php-parser/internal/php8/php8.y

%{
package php8

import (
    "strconv"

    "github.com/laytan/php-parser/pkg/ast"
    "github.com/laytan/php-parser/pkg/token"
)

%}

%union{
    node             ast.Vertex
    token            *token.Token
    list             []ast.Vertex
}

%token <token> T_INCLUDE
%token <token> T_INCLUDE_ONCE
%token <token> T_EXIT
%token <token> T_IF
%token <token> T_LNUMBER
%token <token> T_DNUMBER
%token <token> T_STRING
%token <token> T_STRING_VARNAME
%token <token> T_VARIABLE
%token <token> T_NUM_STRING
%token <token> T_INLINE_HTML
%token <token> T_CHARACTER
%token <token> T_BAD_CHARACTER
%token <token> T_ENCAPSED_AND_WHITESPACE
%token <token> T_CONSTANT_ENCAPSED_STRING
%token <token> T_ECHO
%token <token> T_DO
%token <token> T_WHILE
%token <token> T_ENDWHILE
%token <token> T_FOR
%token <token> T_ENDFOR
%token <token> T_FOREACH
%token <token> T_ENDFOREACH
%token <token> T_DECLARE
%token <token> T_ENDDECLARE
%token <token> T_AS
%token <token> T_SWITCH
%token <token> T_ENDSWITCH
%token <token> T_CASE
%token <token> T_DEFAULT
%token <token> T_BREAK
%token <token> T_CONTINUE
%token <token> T_GOTO
%token <token> T_FUNCTION
%token <token> T_FN
%token <token> T_CONST
%token <token> T_RETURN
%token <token> T_TRY
%token <token> T_CATCH
%token <token> T_FINALLY
%token <token> T_THROW
%token <token> T_USE
%token <token> T_INSTEADOF
%token <token> T_GLOBAL
%token <token> T_VAR
%token <token> T_UNSET
%token <token> T_ISSET
%token <token> T_EMPTY
%token <token> T_HALT_COMPILER
%token <token> T_CLASS
%token <token> T_TRAIT
%token <token> T_INTERFACE
%token <token> T_EXTENDS
%token <token> T_IMPLEMENTS
%token <token> T_OBJECT_OPERATOR
%token <token> T_DOUBLE_ARROW
%token <token> T_LIST
%token <token> T_ARRAY
%token <token> T_CALLABLE
%token <token> T_CLASS_C
%token <token> T_TRAIT_C
%token <token> T_METHOD_C
%token <token> T_FUNC_C
%token <token> T_LINE
%token <token> T_FILE
%token <token> T_COMMENT
%token <token> T_DOC_COMMENT
%token <token> T_OPEN_TAG
%token <token> T_OPEN_TAG_WITH_ECHO
%token <token> T_CLOSE_TAG
%token <token> T_WHITESPACE
%token <token> T_START_HEREDOC
%token <token> T_END_HEREDOC
%token <token> T_DOLLAR_OPEN_CURLY_BRACES
%token <token> T_CURLY_OPEN
%token <token> T_PAAMAYIM_NEKUDOTAYIM
%token <token> T_NAMESPACE
%token <token> T_NS_C
%token <token> T_DIR
%token <token> T_NS_SEPARATOR
%token <token> T_ELLIPSIS
%token <token> T_EVAL
%token <token> T_REQUIRE
%token <token> T_REQUIRE_ONCE
%token <token> T_LOGICAL_OR
%token <token> T_LOGICAL_XOR
%token <token> T_LOGICAL_AND
%token <token> T_INSTANCEOF
%token <token> T_NEW
%token <token> T_CLONE
%token <token> T_ELSEIF
%token <token> T_ELSE
%token <token> T_ENDIF
%token <token> T_PRINT
%token <token> T_YIELD
%token <token> T_STATIC
%token <token> T_ABSTRACT
%token <token> T_FINAL
%token <token> T_PRIVATE
%token <token> T_PROTECTED
%token <token> T_PUBLIC
%token <token> T_INC
%token <token> T_DEC
%token <token> T_YIELD_FROM
%token <token> T_INT_CAST
%token <token> T_DOUBLE_CAST
%token <token> T_STRING_CAST
%token <token> T_ARRAY_CAST
%token <token> T_OBJECT_CAST
%token <token> T_BOOL_CAST
%token <token> T_UNSET_CAST
%token <token> T_COALESCE
%token <token> T_SPACESHIP
%token <token> T_NOELSE
%token <token> T_PLUS_EQUAL
%token <token> T_MINUS_EQUAL
%token <token> T_MUL_EQUAL
%token <token> T_POW_EQUAL
%token <token> T_DIV_EQUAL
%token <token> T_CONCAT_EQUAL
%token <token> T_MOD_EQUAL
%token <token> T_AND_EQUAL
%token <token> T_OR_EQUAL
%token <token> T_XOR_EQUAL
%token <token> T_SL_EQUAL
%token <token> T_SR_EQUAL
%token <token> T_COALESCE_EQUAL
%token <token> T_BOOLEAN_OR
%token <token> T_BOOLEAN_AND
%token <token> T_POW
%token <token> T_SL
%token <token> T_SR
%token <token> T_IS_IDENTICAL
%token <token> T_IS_NOT_IDENTICAL
%token <token> T_IS_EQUAL
%token <token> T_IS_NOT_EQUAL
%token <token> T_IS_SMALLER_OR_EQUAL
%token <token> T_IS_GREATER_OR_EQUAL
%token <token> T_NULLSAFE_OBJECT_OPERATOR
%token <token> T_MATCH
%token <token> T_ATTRIBUTE
%token <token> T_NAME_RELATIVE
%token <token> T_NAME_QUALIFIED
%token <token> T_NAME_FULLY_QUALIFIED
%token <token> T_READONLY
%token <token> T_ENUM
%token <token> T_AMPERSAND_FOLLOWED_BY_VAR_OR_VARARG
%token <token> T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG
%token <token> '"'
%token <token> '`'
%token <token> '{'
%token <token> '}'
%token <token> ';'
%token <token> ':'
%token <token> '('
%token <token> ')'
%token <token> '['
%token <token> ']'
%token <token> '?'
%token <token> '&'
%token <token> '-'
%token <token> '+'
%token <token> '!'
%token <token> '~'
%token <token> '@'
%token <token> '$'
%token <token> ','
%token <token> '|'
%token <token> '='
%token <token> '^'
%token <token> '*'
%token <token> '/'
%token <token> '%'
%token <token> '<'
%token <token> '>'
%token <token> '.'

%right T_THROW
%left T_INCLUDE T_INCLUDE_ONCE T_EVAL T_REQUIRE T_REQUIRE_ONCE
%left ','
%left T_LOGICAL_OR
%left T_LOGICAL_XOR
%left T_LOGICAL_AND
%right T_PRINT
%right T_YIELD
%right T_DOUBLE_ARROW
%right T_YIELD_FROM
%left '=' T_PLUS_EQUAL T_MINUS_EQUAL T_MUL_EQUAL T_DIV_EQUAL T_CONCAT_EQUAL T_MOD_EQUAL T_AND_EQUAL T_OR_EQUAL T_XOR_EQUAL T_SL_EQUAL T_SR_EQUAL T_POW_EQUAL T_COALESCE_EQUAL
%left '?' ':'
%right T_COALESCE
%left T_BOOLEAN_OR
%left T_BOOLEAN_AND
%left '|'
%left '^'
%left T_AMPERSAND_FOLLOWED_BY_VAR_OR_VARARG T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG
%nonassoc T_IS_EQUAL T_IS_NOT_EQUAL T_IS_IDENTICAL T_IS_NOT_IDENTICAL T_SPACESHIP
%nonassoc '<' T_IS_SMALLER_OR_EQUAL '>' T_IS_GREATER_OR_EQUAL
%left '.'
%left T_SL T_SR
%left '+' '-'
%left '*' '/' '%'
%right '!'
%nonassoc T_INSTANCEOF
%right '~' T_INC T_DEC T_INT_CAST T_DOUBLE_CAST T_STRING_CAST T_ARRAY_CAST T_OBJECT_CAST T_BOOL_CAST T_UNSET_CAST '@'
%right T_POW
%right '['
%nonassoc T_NEW T_CLONE
%left T_NOELSE
%left T_ELSEIF
%left T_ELSE
%left T_ENDIF
%right T_STATIC T_ABSTRACT T_FINAL T_PRIVATE T_PROTECTED T_PUBLIC T_READONLY

%type <token> optional_ref optional_arg_ref optional_ellipsis

%type <token> reserved_non_modifiers
%type <token> semi_reserved
%type <token> identifier identifier_ex
%type <token> plain_variable optional_plain_variable
%type <token> optional_comma
%type <token> case_separator
%type <token> use_type
%type <token> ampersand

%type <node> top_statement name statement function_declaration_statement
%type <node> class_declaration_statement trait_declaration_statement
%type <node> interface_declaration_statement
%type <node> const_decl inner_statement for_exprs non_empty_for_exprs
%type <node> expr optional_expr parameter_list non_empty_parameter_list
%type <node> declare_statement finally_statement unset_variable variable
%type <node> parameter argument expr_without_variable global_var_list global_var
%type <node> static_var_list static_var class_statement trait_adaptation trait_precedence trait_alias
%type <node> absolute_trait_method_reference trait_method_reference property echo_expr
%type <node> new_expr anonymous_class class_name class_name_or_var class_name_reference simple_variable
%type <node> internal_functions_in_yacc non_empty_array_pair_list array_pair_list
%type <node> exit_expr scalar lexical_var function_call member_name property_name
%type <node> constant class_constant
%type <node> dereferencable_scalar fully_dereferencable array_object_dereferencable
%type <node> callable_expr callable_variable static_member new_variable
%type <node> encaps_var encaps_var_offset echo_expr_list name_union name_list
%type <node> if_stmt const_list non_empty_argument_list property_list
%type <node> alt_if_stmt lexical_var_list non_empty_lexical_var_list isset_variables class_const_list
%type <node> if_stmt_without_else
%type <node> group_use_declaration inline_use_declaration
%type <node> use_declaration unprefixed_use_declaration non_empty_unprefixed_use_declarations
%type <node> unprefixed_use_declarations non_empty_inline_use_declarations inline_use_declarations use_declarations
%type <node> class_const_decl
%type <node> namespace_name namespace_declaration_name legacy_namespace_name
%type <node> alt_if_stmt_without_else
%type <node> array_pair possible_array_pair
%type <node> isset_variable

%type <node> type_expr type union_type optional_return_type
%type <node> type_expr_without_static type_without_static union_type_without_static optional_type_without_static
%type <node> intersection_type intersection_type_without_static

%type <node> class_modifier
%type <node> argument_list ctor_arguments
%type <node> trait_adaptations
%type <node> switch_case_list
%type <node> method_body
%type <node> foreach_statement for_statement while_statement
%type <node> inline_function attributed_inline_function
%type <node> unset_variables
%type <node> extends_from
%type <node> implements_list
%type <node> interface_extends_list
%type <node> lexical_vars
%type <node> expr_list_allow_comma non_empty_expr_list
%type <node> match match_arm match_arm_list non_empty_match_arm_list
%type <node> catch_list catch
%type <node> property_modifier
%type <node> attribute_decl attribute_group attribute
%type <node> enum_declaration_statement enum_case_expr enum_scalar_type

%type <node> member_modifier
%type <node> foreach_variable


%type <list> encaps_list backticks_expr
%type <list> case_list trait_adaptation_list
%type <list> top_statement_list
%type <list> inner_statement_list class_statement_list
%type <list> method_modifiers variable_modifiers
%type <list> optional_property_modifiers
%type <list> non_empty_member_modifiers class_modifiers optional_class_modifiers
%type <list> optional_attributes attributes

%%

/////////////////////////////////////////////////////////////////////////

start:
        top_statement_list
            {
                yylex.(*Parser).currentToken.Value = nil

                yylex.(*Parser).rootNode = &ast.Root{
                    Position: yylex.(*Parser).builder.Pos.NewNodeListPosition($1),
                    Stmts:  $1,
                    EndTkn: yylex.(*Parser).currentToken,
                }
            }
;

reserved_non_modifiers:
      T_INCLUDE {$$=$1} | T_INCLUDE_ONCE {$$=$1} | T_EVAL {$$=$1} | T_REQUIRE {$$=$1} | T_REQUIRE_ONCE {$$=$1} | T_LOGICAL_OR {$$=$1} | T_LOGICAL_XOR {$$=$1} | T_LOGICAL_AND {$$=$1}
    | T_INSTANCEOF {$$=$1} | T_NEW {$$=$1} | T_CLONE {$$=$1} | T_EXIT {$$=$1} | T_IF {$$=$1} | T_ELSEIF {$$=$1} | T_ELSE {$$=$1} | T_ENDIF {$$=$1} | T_ECHO {$$=$1} | T_DO {$$=$1} | T_WHILE {$$=$1} | T_ENDWHILE {$$=$1}
    | T_FOR {$$=$1} | T_ENDFOR {$$=$1} | T_FOREACH {$$=$1} | T_ENDFOREACH {$$=$1} | T_DECLARE {$$=$1} | T_ENDDECLARE {$$=$1} | T_AS {$$=$1} | T_TRY {$$=$1} | T_CATCH {$$=$1} | T_FINALLY {$$=$1}
    | T_THROW {$$=$1} | T_USE {$$=$1} | T_INSTEADOF {$$=$1} | T_GLOBAL {$$=$1} | T_VAR {$$=$1} | T_UNSET {$$=$1} | T_ISSET {$$=$1} | T_EMPTY {$$=$1} | T_CONTINUE {$$=$1} | T_GOTO {$$=$1}
    | T_FUNCTION {$$=$1} | T_CONST {$$=$1} | T_RETURN {$$=$1} | T_PRINT {$$=$1} | T_YIELD {$$=$1} | T_LIST {$$=$1} | T_SWITCH {$$=$1} | T_ENDSWITCH {$$=$1} | T_CASE {$$=$1} | T_DEFAULT {$$=$1} | T_BREAK {$$=$1}
    | T_ARRAY {$$=$1} | T_CALLABLE {$$=$1} | T_EXTENDS {$$=$1} | T_IMPLEMENTS {$$=$1} | T_NAMESPACE {$$=$1} | T_TRAIT {$$=$1} | T_INTERFACE {$$=$1} | T_CLASS {$$=$1}
    | T_CLASS_C {$$=$1} | T_TRAIT_C {$$=$1} | T_FUNC_C {$$=$1} | T_METHOD_C {$$=$1} | T_LINE {$$=$1} | T_FILE {$$=$1} | T_DIR {$$=$1} | T_NS_C {$$=$1} | T_FN {$$=$1} | T_MATCH {$$=$1} | T_ENUM {$$=$1}
;

semi_reserved:
        reserved_non_modifiers
            {
                $$ = $1
            }
    |   T_STATIC {$$=$1} | T_ABSTRACT {$$=$1} | T_FINAL {$$=$1} | T_PRIVATE {$$=$1}
    |   T_PROTECTED {$$=$1} | T_PUBLIC {$$=$1} | T_READONLY {$$=$1}
;

ampersand:
        T_AMPERSAND_FOLLOWED_BY_VAR_OR_VARARG     { $$ = $1 }
    |   T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG { $$ = $1 }
;

identifier:
        T_STRING        { $$ = $1 }
;

identifier_ex:
        identifier      { $$ = $1 }
    |   semi_reserved   { $$ = $1 }
;

optional_comma:
        /* empty */     { $$ = nil }
    |   ','             { $$ = $1 }
;

optional_plain_variable:
        /* empty */     { $$ = nil }
    |   plain_variable  { $$ = $1 }
;

plain_variable:
      T_VARIABLE        { $$ = $1 }
;

top_statement_list:
        top_statement_list top_statement {
                                           if $2 != nil {
                                               $$ = append($1, $2)
                                           }
                                         }
    |   /* empty */                      { $$ = []ast.Vertex{} }
;

namespace_declaration_name:
         T_STRING                { $$ = yylex.(*Parser).builder.NewName($1) }
    |    semi_reserved           { $$ = yylex.(*Parser).builder.NewName($1) }
    |    T_NAME_QUALIFIED        { $$ = yylex.(*Parser).builder.NewNameQualified($1) }
;

namespace_name:
        T_STRING                 { $$ = yylex.(*Parser).builder.NewName($1) }
    |   T_NAME_QUALIFIED         { $$ = yylex.(*Parser).builder.NewNameQualified($1) }
;

legacy_namespace_name:
        namespace_name           { $$ = $1 }
    |   T_NAME_FULLY_QUALIFIED   { $$ = yylex.(*Parser).builder.NewNameFullyQualified($1) }
;

name:
         T_STRING                { $$ = yylex.(*Parser).builder.NewName($1) }
    |    T_NAME_QUALIFIED        { $$ = yylex.(*Parser).builder.NewNameQualified($1) }
    |    T_NAME_FULLY_QUALIFIED  { $$ = yylex.(*Parser).builder.NewNameFullyQualified($1) }
    |    T_NAME_RELATIVE         { $$ = yylex.(*Parser).builder.NewNameRelative($1) }
;

attribute_decl:
         class_name                          { $$ = yylex.(*Parser).builder.NewAttribute($1, nil) }
    |    class_name argument_list            { $$ = yylex.(*Parser).builder.NewAttribute($1, $2) }
;

attribute_group:
         attribute_decl                      { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
    |    attribute_group ',' attribute_decl  { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

attribute:
         T_ATTRIBUTE attribute_group optional_comma ']'
                                { $$ = yylex.(*Parser).builder.NewAttributeGroup($1, $2, $3, $4) }
;

attributes:
          attribute             { $$ = []ast.Vertex{$1} }
    |     attributes attribute  { $$ = append($1, $2) }
;

optional_attributes:
         /* empty */            { $$ = nil }
    |    attributes             { $$ = $1 }
;

top_statement:
        error                           { $$ = nil }
    |   statement                       { $$ = $1 }
    |   function_declaration_statement  { $$ = $1 }
    |   class_declaration_statement     { $$ = $1 }
    |   trait_declaration_statement     { $$ = $1 }
    |   interface_declaration_statement { $$ = $1 }
    |   enum_declaration_statement      { $$ = $1 }
    |   T_HALT_COMPILER '(' ')' ';'
            {
                $$ = &ast.StmtHaltCompiler{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    HaltCompilerTkn:     $1,
                    OpenParenthesisTkn:  $2,
                    CloseParenthesisTkn: $3,
                    SemiColonTkn:        $4,
                }
            }
    |   T_NAMESPACE namespace_declaration_name ';'
            { $$ = yylex.(*Parser).builder.NewNamespace($1, $2, nil, nil, nil, $3) }
    |   T_NAMESPACE namespace_declaration_name '{' top_statement_list '}'
            { $$ = yylex.(*Parser).builder.NewNamespace($1, $2, $3, $4, $5, nil) }
    |   T_NAMESPACE '{' top_statement_list '}'
            { $$ = yylex.(*Parser).builder.NewNamespace($1, nil, $2, $3, $4, nil) }

    |   T_USE use_declarations ';'
            { $$ = yylex.(*Parser).builder.NewUseList($1, nil, $2, $3) }
    |   T_USE use_type use_declarations ';'
            { $$ = yylex.(*Parser).builder.NewUseList($1, $2, $3, $4) }
    |   group_use_declaration
            { $$ = $1 }

    |   T_CONST const_list ';'
            {
                $$ = &ast.StmtConstList{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    ConstTkn:      $1,
                    Consts:        $2.(*ParserSeparatedList).Items,
                    SeparatorTkns: $2.(*ParserSeparatedList).SeparatorTkns,
                    SemiColonTkn:  $3,
                }
            }
;

use_type:
        T_FUNCTION { $$ = $1 }
    |   T_CONST    { $$ = $1 }
;

group_use_declaration:
        T_USE use_type legacy_namespace_name T_NS_SEPARATOR '{' unprefixed_use_declarations '}' ';'
                    { $$ = yylex.(*Parser).builder.NewGroupUseList($1, $2, $3, $4, $5, $6, $7, $8) }
    |   T_USE legacy_namespace_name T_NS_SEPARATOR '{' inline_use_declarations '}' ';'
                    { $$ = yylex.(*Parser).builder.NewGroupUseList($1, nil, $2, $3, $4, $5, $6, $7) }
;

inline_use_declarations:
        non_empty_inline_use_declarations optional_comma
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, nil) }
;

non_empty_inline_use_declarations:
        non_empty_inline_use_declarations  ',' inline_use_declaration
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
    |   inline_use_declaration
            { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
;

unprefixed_use_declarations:
      non_empty_unprefixed_use_declarations optional_comma
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, nil) }
;

non_empty_unprefixed_use_declarations:
        non_empty_unprefixed_use_declarations ',' unprefixed_use_declaration
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
    |   unprefixed_use_declaration
            { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
;

use_declarations:
        use_declarations ',' use_declaration  { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
    |   use_declaration                       { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
;

inline_use_declaration:
        unprefixed_use_declaration            { $$ = $1 }
    |   use_type unprefixed_use_declaration   {
                                               decl := $2.(*ast.StmtUse)
                                               decl.Type = yylex.(*Parser).builder.NewIdentifier($1)
                                               decl.Position = yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2)
                                               $$ = $2
                                              }
;

unprefixed_use_declaration:
        namespace_name                        { $$ = yylex.(*Parser).builder.NewUse(nil, $1, nil, nil) }
    |   namespace_name T_AS identifier        { $$ = yylex.(*Parser).builder.NewUse(nil, $1, $2, $3)}
;

use_declaration:
        legacy_namespace_name                 { $$ = yylex.(*Parser).builder.NewUse(nil, $1, nil, nil) }
    |   legacy_namespace_name T_AS identifier { $$ = yylex.(*Parser).builder.NewUse(nil, $1, $2, $3)}
;

const_list:
        const_list ',' const_decl             { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
    |   const_decl                            { $$ = yylex.(*Parser).builder.NewSeparatedList($1)}
;

inner_statement_list:
        inner_statement_list inner_statement  {
                                                if $2 != nil {
                                                    $$ = append($1, $2)
                                                }
                                              }
    |   /* empty */                           { $$ = []ast.Vertex{} }
;

inner_statement:
        error                                 { $$ = nil }
    |   statement                             { $$ = $1 }
    |   function_declaration_statement        { $$ = $1 }
    |   class_declaration_statement           { $$ = $1 }
    |   trait_declaration_statement           { $$ = $1 }
    |   interface_declaration_statement       { $$ = $1 }
    |   enum_declaration_statement            { $$ = $1 }
    |   T_HALT_COMPILER '(' ')' ';'
            {
                $$ = &ast.StmtHaltCompiler{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    HaltCompilerTkn:     $1,
                    OpenParenthesisTkn:  $2,
                    CloseParenthesisTkn: $3,
                    SemiColonTkn:        $4,
                }
            }

statement:
        '{' inner_statement_list '}'
            {
                $$ = &ast.StmtStmtList{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenCurlyBracketTkn:  $1,
                    Stmts:                $2,
                    CloseCurlyBracketTkn: $3,
                }
            }
    |   if_stmt
            {
                $$ = $1
            }
    |   alt_if_stmt
            {
                $$ = $1
            }
    |   T_WHILE '(' expr ')' while_statement
            {
                $5.(*ast.StmtWhile).WhileTkn = $1
                $5.(*ast.StmtWhile).OpenParenthesisTkn = $2
                $5.(*ast.StmtWhile).Cond = $3
                $5.(*ast.StmtWhile).CloseParenthesisTkn = $4
                $5.(*ast.StmtWhile).Position = yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $5)

                $$ = $5
            }
    |   T_DO statement T_WHILE '(' expr ')' ';'
            {
                $$ = &ast.StmtDo{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $7),
                    DoTkn:               $1,
                    Stmt:                $2,
                    WhileTkn:            $3,
                    OpenParenthesisTkn:  $4,
                    Cond:                $5,
                    CloseParenthesisTkn: $6,
                    SemiColonTkn:        $7,
                }
            }
    |   T_FOR '(' for_exprs ';' for_exprs ';' for_exprs ')' for_statement
            {
                $9.(*ast.StmtFor).ForTkn = $1
                $9.(*ast.StmtFor).OpenParenthesisTkn = $2
                $9.(*ast.StmtFor).Init = $3.(*ParserSeparatedList).Items
                $9.(*ast.StmtFor).InitSeparatorTkns = $3.(*ParserSeparatedList).SeparatorTkns
                $9.(*ast.StmtFor).InitSemiColonTkn = $4
                $9.(*ast.StmtFor).Cond = $5.(*ParserSeparatedList).Items
                $9.(*ast.StmtFor).CondSeparatorTkns = $5.(*ParserSeparatedList).SeparatorTkns
                $9.(*ast.StmtFor).CondSemiColonTkn = $6
                $9.(*ast.StmtFor).Loop = $7.(*ParserSeparatedList).Items
                $9.(*ast.StmtFor).LoopSeparatorTkns = $7.(*ParserSeparatedList).SeparatorTkns
                $9.(*ast.StmtFor).CloseParenthesisTkn = $8
                $9.(*ast.StmtFor).Position = yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $9)

                $$ = $9
            }
    |   T_SWITCH '(' expr ')' switch_case_list
            {
                $5.(*ast.StmtSwitch).SwitchTkn = $1
                $5.(*ast.StmtSwitch).OpenParenthesisTkn = $2
                $5.(*ast.StmtSwitch).Cond = $3
                $5.(*ast.StmtSwitch).CloseParenthesisTkn = $4
                $5.(*ast.StmtSwitch).Position = yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $5)

                $$ = $5
            }
    |   T_BREAK optional_expr ';'
            {
                $$ = &ast.StmtBreak{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    BreakTkn:     $1,
                    Expr:         $2,
                    SemiColonTkn: $3,
                }
            }
    |   T_CONTINUE optional_expr ';'
            {
                $$ = &ast.StmtContinue{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    ContinueTkn:  $1,
                    Expr:         $2,
                    SemiColonTkn: $3,
                }
            }
    |   T_RETURN optional_expr ';'
            {
                $$ = &ast.StmtReturn{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    ReturnTkn:    $1,
                    Expr:         $2,
                    SemiColonTkn: $3,
                }
            }
    |   T_GLOBAL global_var_list ';'
            {
                $2.(*ast.StmtGlobal).GlobalTkn = $1
                $2.(*ast.StmtGlobal).SemiColonTkn = $3
                $2.(*ast.StmtGlobal).Position = yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3)

                $$ = $2
            }
    |   T_STATIC static_var_list ';'
            {
                $2.(*ast.StmtStatic).StaticTkn = $1
                $2.(*ast.StmtStatic).SemiColonTkn = $3
                $2.(*ast.StmtStatic).Position = yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3)

                $$ = $2
            }
    |   T_ECHO echo_expr_list ';'
            {
                $2.(*ast.StmtEcho).EchoTkn = $1
                $2.(*ast.StmtEcho).SemiColonTkn = $3
                $2.(*ast.StmtEcho).Position = yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3)

                $$ = $2
            }
    |   T_INLINE_HTML
            {
                $$ = &ast.StmtInlineHtml{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    InlineHtmlTkn: $1,
                    Value:         $1.Value,
                }
            }
    |   expr ';'
            {
                $$ = yylex.(*Parser).builder.NewExpressionStmt($1, $2)
            }
    |   T_UNSET '(' unset_variables optional_comma ')' ';'
            {
                $3.(*ast.StmtUnset).UnsetTkn = $1
                $3.(*ast.StmtUnset).OpenParenthesisTkn = $2
                if $4 != nil {
                    $3.(*ast.StmtUnset).SeparatorTkns = append($3.(*ast.StmtUnset).SeparatorTkns, $4)
                }
                $3.(*ast.StmtUnset).CloseParenthesisTkn = $5
                $3.(*ast.StmtUnset).SemiColonTkn = $6
                $3.(*ast.StmtUnset).Position = yylex.(*Parser).builder.Pos.NewTokensPosition($1, $6)

                $$ = $3
            }
    |   T_FOREACH '(' expr T_AS foreach_variable ')' foreach_statement
            {
                foreach := $7.(*ast.StmtForeach)

                foreach.Position            = yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $7)
                foreach.ForeachTkn          = $1
                foreach.OpenParenthesisTkn  = $2
                foreach.Expr                = $3
                foreach.AsTkn               = $4
                foreach.Var                 = $5
                foreach.CloseParenthesisTkn = $6

                if val, ok := $5.(*ast.StmtForeach); ok {
                    foreach.AmpersandTkn    = val.AmpersandTkn
                    foreach.Var             = val.Var
                }

                $$ = foreach
            }
    |   T_FOREACH '(' expr T_AS variable T_DOUBLE_ARROW foreach_variable ')' foreach_statement
            {
                foreach := $9.(*ast.StmtForeach)

                foreach.Position            = yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $9)
                foreach.ForeachTkn          = $1
                foreach.OpenParenthesisTkn  = $2
                foreach.Expr                = $3
                foreach.AsTkn               = $4
                foreach.Key                 = $5
                foreach.DoubleArrowTkn      = $6
                foreach.Var                 = $7
                foreach.CloseParenthesisTkn = $8

                if val, ok := $7.(*ast.StmtForeach); ok {
                    foreach.AmpersandTkn    = val.AmpersandTkn
                    foreach.Var             = val.Var
                }

                $$ = foreach
            }
    |   T_DECLARE '(' const_list ')' declare_statement
            {
                $5.(*ast.StmtDeclare).DeclareTkn = $1
                $5.(*ast.StmtDeclare).OpenParenthesisTkn = $2
                $5.(*ast.StmtDeclare).Consts = $3.(*ParserSeparatedList).Items
                $5.(*ast.StmtDeclare).SeparatorTkns = $3.(*ParserSeparatedList).SeparatorTkns
                $5.(*ast.StmtDeclare).CloseParenthesisTkn = $4
                $5.(*ast.StmtDeclare).Position = yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $5)

                $$ = $5
            }
    |   ';'
            {
                $$ = &ast.StmtNop{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    SemiColonTkn: $1,
                }
            }
    |   T_TRY '{' inner_statement_list '}' catch_list finally_statement
            {
                $$ = yylex.(*Parser).builder.NewTry($1, $2, $3, $4, $5, $6)
            }
    |   T_GOTO identifier ';'
            {
                $$ = &ast.StmtGoto{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    GotoTkn: $1,
                    Label: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($2),
                        IdentifierTkn: $2,
                        Value:         $2.Value,
                    },
                    SemiColonTkn: $3,
                }
            }
    |   identifier ':'
            {
                $$ = &ast.StmtLabel{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $2),
                    Name: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        IdentifierTkn: $1,
                        Value:         $1.Value,
                    },
                    ColonTkn: $2,
                }
            }

catch_list:
        /* empty */         { $$ = yylex.(*Parser).builder.NewEmptySeparatedList() }
    |   catch_list catch    { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, nil, $2) }
;

catch:
        T_CATCH '(' name_union optional_plain_variable ')' '{' inner_statement_list '}'
                            { $$ = yylex.(*Parser).builder.NewCatch($1, $2, $3, $4, $5, $6, $7, $8) }
;

name_union:
        name                { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
    |   name_union '|' name { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

finally_statement:
        /* empty */
            {
                $$ = nil
            }
    |   T_FINALLY '{' inner_statement_list '}'
            {
                $$ = &ast.StmtFinally{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    FinallyTkn:           $1,
                    OpenCurlyBracketTkn:  $2,
                    Stmts:                $3,
                    CloseCurlyBracketTkn: $4,
                }
            }
;

unset_variables:
        unset_variable
            {
                $$ = &ast.StmtUnset{
                    Vars: []ast.Vertex{$1},
                }
            }
    |   unset_variables ',' unset_variable
            {
                $1.(*ast.StmtUnset).Vars = append($1.(*ast.StmtUnset).Vars, $3)
                $1.(*ast.StmtUnset).SeparatorTkns = append($1.(*ast.StmtUnset).SeparatorTkns, $2)

                $$ = $1
            }
;

unset_variable:
        variable { $$ = $1 }
;

function_declaration_statement:
        T_FUNCTION optional_ref identifier '(' parameter_list ')' optional_return_type '{' inner_statement_list '}'
            { $$ = yylex.(*Parser).builder.NewFunction(nil, $1, $2, $3, $4, $5, $6, $7, $8, $9, $10) }
    |   attributes
        T_FUNCTION optional_ref identifier '(' parameter_list ')' optional_return_type '{' inner_statement_list '}'
            { $$ = yylex.(*Parser).builder.NewFunction($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11) }
;

optional_ref:
        /* empty */                    { $$ = nil }
    |   ampersand                      { $$ = $1 }
;

optional_arg_ref:
        /* empty */                           { $$ = nil }
    |   T_AMPERSAND_FOLLOWED_BY_VAR_OR_VARARG { $$ = $1 }
;

optional_ellipsis:
        /* empty */                    { $$ = nil }
    |   T_ELLIPSIS                     { $$ = $1 }
;

optional_class_modifiers:
        /* empty */                    { $$ = nil }
    |   class_modifiers                { $$ = $1 }
;

class_modifiers:
        class_modifier                 { $$ = []ast.Vertex{$1} }
    |   class_modifiers class_modifier { $$ = append($1, $2) }
;

class_modifier:
        T_ABSTRACT                     { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_FINAL                        { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_READONLY                     { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
;

class_declaration_statement:
    optional_attributes optional_class_modifiers
    T_CLASS identifier extends_from implements_list '{' class_statement_list '}'
            { $$ = yylex.(*Parser).builder.NewClass($1, $2, $3, $4, $5, $6, $7, $8, $9) }
;

trait_declaration_statement:
        optional_attributes
        T_TRAIT identifier '{' class_statement_list '}'
            { $$ = yylex.(*Parser).builder.NewTrait($1, $2, $3, $4, $5, $6) }
;

interface_declaration_statement:
        optional_attributes
        T_INTERFACE identifier interface_extends_list '{' class_statement_list '}'
            { $$ = yylex.(*Parser).builder.NewInterface($1, $2, $3, $4, $5, $6, $7) }
;

enum_declaration_statement:
        optional_attributes
        T_ENUM identifier enum_scalar_type implements_list '{' class_statement_list '}'
            { $$ = yylex.(*Parser).builder.NewEnum($1, $2, $3, $4, $5, $6, $7, $8) }
;

enum_scalar_type:
        /* empty */   { $$ = nil }
    |   ':' type      { $$ = yylex.(*Parser).builder.NewEnumType($1, $2) }

enum_case_expr:
        /* empty */   { $$ = nil }
    |   '=' expr      { $$ = yylex.(*Parser).builder.NewEnumExpr($1, $2) }

extends_from:
        /* empty */
            {
                $$ = nil
            }
    |   T_EXTENDS name
            {
                $$ = &ast.StmtClass{
                    Position:   yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    ExtendsTkn: $1,
                    Extends:    $2,
                }
            }
;

interface_extends_list:
        /* empty */
            {
                $$ = nil
            }
    |   T_EXTENDS name_list
            {
                $$ = &ast.StmtInterface{
                    Position:             yylex.(*Parser).builder.Pos.NewTokenNodeListPosition($1, $2.(*ParserSeparatedList).Items),
                    ExtendsTkn:           $1,
                    Extends:              $2.(*ParserSeparatedList).Items,
                    ExtendsSeparatorTkns: $2.(*ParserSeparatedList).SeparatorTkns,
                };
            }
;

implements_list:
        /* empty */
            {
                $$ = nil
            }
    |   T_IMPLEMENTS name_list
            {
                $$ = &ast.StmtClass{
                    Position:                yylex.(*Parser).builder.Pos.NewTokenNodeListPosition($1, $2.(*ParserSeparatedList).Items),
                    ImplementsTkn:           $1,
                    Implements:              $2.(*ParserSeparatedList).Items,
                    ImplementsSeparatorTkns: $2.(*ParserSeparatedList).SeparatorTkns,
                };
            }
;

foreach_variable:
        variable
            {
                $$ = $1
            }
    |   ampersand variable
            {
                $$ = &ast.StmtForeach{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    AmpersandTkn: $1,
                    Var:          $2,
                }
            }
    |   T_LIST '(' array_pair_list ')'
            {
                $$ = &ast.ExprList{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    ListTkn:         $1,
                    OpenBracketTkn:  $2,
                    Items:           $3.(*ParserSeparatedList).Items,
                    SeparatorTkns:   $3.(*ParserSeparatedList).SeparatorTkns,
                    CloseBracketTkn: $4,
                }
            }
    |   '[' array_pair_list ']'
            {
                $$ = &ast.ExprList{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenBracketTkn:  $1,
                    Items:           $2.(*ParserSeparatedList).Items,
                    SeparatorTkns:   $2.(*ParserSeparatedList).SeparatorTkns,
                    CloseBracketTkn: $3,
                }
            }
;

for_statement:
        statement
            {
                $$ = &ast.StmtFor{
                    Position: yylex.(*Parser).builder.Pos.NewNodePosition($1),
                    Stmt: $1,
                }
            }
    |   ':' inner_statement_list T_ENDFOR ';'
            {
                $$ = &ast.StmtFor{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    ColonTkn: $1,
                    Stmt: &ast.StmtStmtList{
                        Position: yylex.(*Parser).builder.Pos.NewNodeListPosition($2),
                        Stmts: $2,
                    },
                    EndForTkn:    $3,
                    SemiColonTkn: $4,
                }
            }
;

foreach_statement:
        statement
            {
                $$ = &ast.StmtForeach{
                    Position: yylex.(*Parser).builder.Pos.NewNodePosition($1),
                    Stmt: $1,
                }
            }
    |   ':' inner_statement_list T_ENDFOREACH ';'
            {
                $$ = &ast.StmtForeach{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    ColonTkn: $1,
                    Stmt: &ast.StmtStmtList{
                        Position: yylex.(*Parser).builder.Pos.NewNodeListPosition($2),
                        Stmts: $2,
                    },
                    EndForeachTkn: $3,
                    SemiColonTkn:  $4,
                }
            }
;

declare_statement:
        statement
            {
                $$ = &ast.StmtDeclare{
                    Position: yylex.(*Parser).builder.Pos.NewNodePosition($1),
                    Stmt: $1,
                }
            }
    |   ':' inner_statement_list T_ENDDECLARE ';'
            {
                $$ = &ast.StmtDeclare{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    ColonTkn: $1,
                    Stmt: &ast.StmtStmtList{
                        Position: yylex.(*Parser).builder.Pos.NewNodeListPosition($2),
                        Stmts: $2,
                    },
                    EndDeclareTkn: $3,
                    SemiColonTkn:  $4,
                }
            }
;

switch_case_list:
        '{' case_list '}'
            {
                $$ = &ast.StmtSwitch{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenCurlyBracketTkn:  $1,
                    Cases:                $2,
                    CloseCurlyBracketTkn: $3,
                }
            }
    |   '{' ';' case_list '}'
            {
                $$ = &ast.StmtSwitch{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    OpenCurlyBracketTkn:  $1,
                    CaseSeparatorTkn:     $2,
                    Cases:                $3,
                    CloseCurlyBracketTkn: $4,
                }
            }
    |   ':' case_list T_ENDSWITCH ';'
            {
                $$ = &ast.StmtSwitch{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    ColonTkn:     $1,
                    Cases:        $2,
                    EndSwitchTkn: $3,
                    SemiColonTkn: $4,
                }
            }
    |   ':' ';' case_list T_ENDSWITCH ';'
            {
                $$ = &ast.StmtSwitch{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $5),
                    ColonTkn:         $1,
                    CaseSeparatorTkn: $2,
                    Cases:            $3,
                    EndSwitchTkn:     $4,
                    SemiColonTkn:     $5,
                }
            }
;

case_list:
        /* empty */
            {
                $$ = nil
            }
    |   case_list T_CASE expr case_separator inner_statement_list
            {
                $$ = append($1, &ast.StmtCase{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodeListPosition($2, $5),
                    CaseTkn:          $2,
                    Cond:             $3,
                    CaseSeparatorTkn: $4,
                    Stmts:            $5,
                })
            }
    |   case_list T_DEFAULT case_separator inner_statement_list
            {
                $$ = append($1, &ast.StmtDefault{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodeListPosition($2, $4),
                    DefaultTkn:       $2,
                    CaseSeparatorTkn: $3,
                    Stmts:            $4,
                })
            }
;

case_separator:
        ':' { $$ = $1 }
    |   ';' { $$ = $1 }
;

while_statement:
        statement
            {
                $$ = &ast.StmtWhile{
                    Position: yylex.(*Parser).builder.Pos.NewNodePosition($1),
                    Stmt: $1,
                }
            }
    |   ':' inner_statement_list T_ENDWHILE ';'
            {
                $$ = &ast.StmtWhile{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    ColonTkn: $1,
                    Stmt: &ast.StmtStmtList{
                        Position: yylex.(*Parser).builder.Pos.NewNodeListPosition($2),
                        Stmts: $2,
                    },
                    EndWhileTkn:  $3,
                    SemiColonTkn: $4,
                }
            }
;

if_stmt_without_else:
        T_IF '(' expr ')' statement
            {
                $$ = &ast.StmtIf{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $5),
                    IfTkn:               $1,
                    OpenParenthesisTkn:  $2,
                    Cond:                $3,
                    CloseParenthesisTkn: $4,
                    Stmt:                $5,
                }
            }
    |   if_stmt_without_else T_ELSEIF '(' expr ')' statement
            {
                $1.(*ast.StmtIf).ElseIf = append($1.(*ast.StmtIf).ElseIf, &ast.StmtElseIf{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($2, $6),
                    ElseIfTkn:           $2,
                    OpenParenthesisTkn:  $3,
                    Cond:                $4,
                    CloseParenthesisTkn: $5,
                    Stmt:                $6,
                })

                $1.(*ast.StmtIf).Position = yylex.(*Parser).builder.Pos.NewNodesPosition($1, $6)

                $$ = $1
            }
;

if_stmt:
        if_stmt_without_else %prec T_NOELSE
            {
                $$ = $1
            }
    |   if_stmt_without_else T_ELSE statement
            {
                $1.(*ast.StmtIf).Else = &ast.StmtElse{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($2, $3),
                    ElseTkn: $2,
                    Stmt:    $3,
                }

                $1.(*ast.StmtIf).Position = yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3)

                $$ = $1
            }
;

alt_if_stmt_without_else:
        T_IF '(' expr ')' ':' inner_statement_list
            {
                $$ = &ast.StmtIf{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodeListPosition($1, $6),
                    IfTkn:               $1,
                    OpenParenthesisTkn:  $2,
                    Cond:                $3,
                    CloseParenthesisTkn: $4,
                    ColonTkn:            $5,
                    Stmt: &ast.StmtStmtList{
                        Position: yylex.(*Parser).builder.Pos.NewNodeListPosition($6),
                        Stmts: $6,
                    },
                }
            }
    |   alt_if_stmt_without_else T_ELSEIF '(' expr ')' ':' inner_statement_list
            {
                $1.(*ast.StmtIf).ElseIf = append($1.(*ast.StmtIf).ElseIf, &ast.StmtElseIf{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodeListPosition($2, $7),
                    ElseIfTkn:           $2,
                    OpenParenthesisTkn:  $3,
                    Cond:                $4,
                    CloseParenthesisTkn: $5,
                    ColonTkn:            $6,
                    Stmt: &ast.StmtStmtList{
                        Position: yylex.(*Parser).builder.Pos.NewNodeListPosition($7),
                        Stmts: $7,
                    },
                })

                $$ = $1
            }
;

alt_if_stmt:
        alt_if_stmt_without_else T_ENDIF ';'
            {
                $1.(*ast.StmtIf).EndIfTkn = $2
                $1.(*ast.StmtIf).SemiColonTkn = $3
                $1.(*ast.StmtIf).Position = yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $3)

                $$ = $1
            }
    |   alt_if_stmt_without_else T_ELSE ':' inner_statement_list T_ENDIF ';'
            {
                $1.(*ast.StmtIf).Else = &ast.StmtElse{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodeListPosition($2, $4),
                    ElseTkn:  $2,
                    ColonTkn: $3,
                    Stmt: &ast.StmtStmtList{
                        Position: yylex.(*Parser).builder.Pos.NewNodeListPosition($4),
                        Stmts: $4,
                    },
                }
                $1.(*ast.StmtIf).EndIfTkn = $5
                $1.(*ast.StmtIf).SemiColonTkn = $6
                $1.(*ast.StmtIf).Position = yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $6)

                $$ = $1
            }
;

parameter_list:
        non_empty_parameter_list optional_comma        { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, nil) }
    |   /* empty */                                    { $$ = yylex.(*Parser).builder.NewEmptySeparatedList() }
;

non_empty_parameter_list:
        parameter                                      { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
    |   non_empty_parameter_list ',' parameter         { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

optional_property_modifiers:
         /* empty */                                   { $$ = nil }
    |    optional_property_modifiers property_modifier { $$ = append($1, $2) }
;

property_modifier:
        T_PUBLIC                  { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_PROTECTED               { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_PRIVATE                 { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_READONLY                { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
;

parameter:
        optional_attributes optional_property_modifiers optional_type_without_static
        optional_arg_ref optional_ellipsis plain_variable
            { $$ = yylex.(*Parser).builder.NewParameter($1, $2, $3, $4, $5, $6, nil, nil, false) }
    |   optional_attributes optional_property_modifiers optional_type_without_static
        optional_arg_ref optional_ellipsis plain_variable '=' expr
            { $$ = yylex.(*Parser).builder.NewParameter($1, $2, $3, $4, $5, $6, $7, $8, true) }
;

type_expr:
        type                { $$ = $1 }
    |   '?' type            { $$ = yylex.(*Parser).builder.NewNullableType($1, $2) }
    |   union_type          { $$ = yylex.(*Parser).builder.NewUnionType($1) }
    |   intersection_type   { $$ = yylex.(*Parser).builder.NewIntersectionType($1) }
;

type:
        type_without_static { $$ = $1 }
    |   T_STATIC            { $$ = yylex.(*Parser).builder.NewNameType($1) }
;

type_without_static:
        T_ARRAY             { $$ = yylex.(*Parser).builder.NewNameType($1) }
    |   T_CALLABLE          { $$ = yylex.(*Parser).builder.NewNameType($1) }
    |   name                { $$ = $1 }
;

union_type:
        type '|' type       { $$ = yylex.(*Parser).builder.NewSeparatedListWithTwoElements($1, $2, $3) }
    |   union_type '|' type { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

union_type_without_static:
        type_without_static '|' type_without_static
            { $$ = yylex.(*Parser).builder.NewSeparatedListWithTwoElements($1, $2, $3) }
    |   union_type_without_static '|' type_without_static
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

intersection_type:
        type T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG type
            { $$ = yylex.(*Parser).builder.NewSeparatedListWithTwoElements($1, $2, $3) }
    |   intersection_type T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG type
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

intersection_type_without_static:
        type_expr_without_static T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG type_expr_without_static
            { $$ = yylex.(*Parser).builder.NewSeparatedListWithTwoElements($1, $2, $3) }
    |   intersection_type_without_static T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG type_expr_without_static
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

type_expr_without_static:
        type_without_static              { $$ = $1 }
    |   '?' type_without_static          { $$ = yylex.(*Parser).builder.NewNullableType($1, $2) }
    |   union_type_without_static        { $$ = yylex.(*Parser).builder.NewUnionType($1) }
    |   intersection_type_without_static { $$ = yylex.(*Parser).builder.NewIntersectionType($1) }
;

optional_type_without_static:
        /* empty */               { $$ = nil }
    |   type_expr_without_static  { $$ = $1 }
;

optional_return_type:
        /* empty */               { $$ = &ReturnType{} }
    |   ':' type_expr             { $$ = yylex.(*Parser).builder.NewReturnType($1, $2) }
;

argument_list:
        '(' ')'                   { $$ = yylex.(*Parser).builder.NewArgumentList($1, nil, nil, nil, $2) }
    |   '(' non_empty_argument_list optional_comma ')'
                                  { $$ = yylex.(*Parser).builder.NewArgumentList($1, $2, $3, nil, $4) }
    |   '(' T_ELLIPSIS ')'        { $$ = yylex.(*Parser).builder.NewArgumentList($1, nil, nil, $2, $3) }
;

non_empty_argument_list:
        argument                  { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
    |   non_empty_argument_list ',' argument
                                  { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

argument:
        expr                      { $$ = yylex.(*Parser).builder.NewArgument($1) }
    |   T_ELLIPSIS expr           { $$ = yylex.(*Parser).builder.NewVariadicArgument($1, $2) }
    |   identifier_ex ':' expr    { $$ = yylex.(*Parser).builder.NewNamedArgument($1, $2, $3) }
;

global_var_list:
        global_var_list ',' global_var
            {
                $1.(*ast.StmtGlobal).Vars = append($1.(*ast.StmtGlobal).Vars, $3)
                $1.(*ast.StmtGlobal).SeparatorTkns = append($1.(*ast.StmtGlobal).SeparatorTkns, $2)

                $$ = $1
            }
    |   global_var
            {
                $$ = &ast.StmtGlobal{
                    Vars: []ast.Vertex{$1},
                }
            }
;

global_var:
        simple_variable { $$ = $1 }
;

static_var_list:
        static_var_list ',' static_var
            {
                $1.(*ast.StmtStatic).Vars = append($1.(*ast.StmtStatic).Vars, $3)
                $1.(*ast.StmtStatic).SeparatorTkns = append($1.(*ast.StmtStatic).SeparatorTkns, $2)

                $$ = $1
            }
    |   static_var
            {
                $$ = &ast.StmtStatic{
                    Vars: []ast.Vertex{$1},
                }
            }
;

static_var:
        plain_variable
            {
                $$ = &ast.StmtStaticVar{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    Var: &ast.ExprVariable{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        Name: &ast.Identifier{
                            Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                            IdentifierTkn: $1,
                            Value:         $1.Value,
                        },
                    },
                }
            }
    |   plain_variable '=' expr
            {
                $$ = &ast.StmtStaticVar{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $3),
                    Var: &ast.ExprVariable{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        Name: &ast.Identifier{
                            Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                            IdentifierTkn: $1,
                            Value:         $1.Value,
                        },
                    },
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
;

class_statement_list:
        class_statement_list class_statement { $$ = append($1, $2) }
    |   /* empty */                          { $$ = []ast.Vertex{} }
;

class_statement:
        optional_attributes variable_modifiers optional_type_without_static property_list ';'
            { $$ = yylex.(*Parser).builder.NewPropertyList($1, $2, $3, $4, $5) }
    |   optional_attributes method_modifiers T_CONST class_const_list ';'
            { $$ = yylex.(*Parser).builder.NewClassConstList($1, $2, $3, $4, $5) }
    |   optional_attributes method_modifiers T_FUNCTION optional_ref identifier_ex '(' parameter_list ')' optional_return_type method_body
            { $$ = yylex.(*Parser).builder.NewClassMethod($1, $2, $3, $4, $5, $6, $7, $8, $9, $10) }
    |   T_USE name_list trait_adaptations
            {
                traitUse := &ast.StmtTraitUse{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $3),
                    UseTkn:        $1,
                    Traits:        $2.(*ParserSeparatedList).Items,
                    SeparatorTkns: $2.(*ParserSeparatedList).SeparatorTkns,
                }

                switch n := $3.(type) {
                case *TraitAdaptationList :
                    traitUse.OpenCurlyBracketTkn = n.OpenCurlyBracketTkn
                    traitUse.Adaptations = n.Adaptations
                    traitUse.CloseCurlyBracketTkn = n.CloseCurlyBracketTkn
                case *ast.StmtNop :
                    traitUse.SemiColonTkn = n.SemiColonTkn
                };

                $$ = traitUse
            }
    |   optional_attributes T_CASE identifier enum_case_expr ';'
            { $$ = yylex.(*Parser).builder.NewEnumCase($1, $2, $3, $4, $5) }
;

name_list:
        name               { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
    |   name_list ',' name { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

trait_adaptations:
        ';'
            {
                $$ = &ast.StmtNop{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    SemiColonTkn: $1,
                }
            }
    |   '{' '}'
            {
                $$ = &TraitAdaptationList{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $2),
                    OpenCurlyBracketTkn:  $1,
                    CloseCurlyBracketTkn: $2,
                }
            }
    |   '{' trait_adaptation_list '}'
            {
                $$ = &TraitAdaptationList{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenCurlyBracketTkn:  $1,
                    Adaptations:          $2,
                    CloseCurlyBracketTkn: $3,
                }
            }
;

trait_adaptation_list:
        trait_adaptation                       { $$ = []ast.Vertex{$1} }
    |   trait_adaptation_list trait_adaptation { $$ = append($1, $2) }
;

trait_adaptation:
        trait_precedence ';'
            {
                $1.(*ast.StmtTraitUsePrecedence).SemiColonTkn = $2

                $$ = $1;
            }
    |   trait_alias ';'
            {
                $1.(*ast.StmtTraitUseAlias).SemiColonTkn = $2

                $$ = $1;
            }
;

trait_precedence:
        absolute_trait_method_reference T_INSTEADOF name_list
            {
                $$ = &ast.StmtTraitUsePrecedence{
                    Position:       yylex.(*Parser).builder.Pos.NewNodeNodeListPosition($1, $3.(*ParserSeparatedList).Items),
                    Trait:          $1.(*TraitMethodRef).Trait,
                    DoubleColonTkn: $1.(*TraitMethodRef).DoubleColonTkn,
                    Method:         $1.(*TraitMethodRef).Method,
                    InsteadofTkn:   $2,
                    Insteadof:      $3.(*ParserSeparatedList).Items,
                    SeparatorTkns:  $3.(*ParserSeparatedList).SeparatorTkns,
                }
            }
;

trait_alias:
        trait_method_reference T_AS identifier
            {
                $$ = &ast.StmtTraitUseAlias{
                    Position:       yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $3),
                    Trait:          $1.(*TraitMethodRef).Trait,
                    DoubleColonTkn: $1.(*TraitMethodRef).DoubleColonTkn,
                    Method:         $1.(*TraitMethodRef).Method,
                    AsTkn:          $2,
                    Alias: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($3),
                        IdentifierTkn: $3,
                        Value:         $3.Value,
                    },
                }
            }
    |   trait_method_reference T_AS reserved_non_modifiers
            {
                $$ = &ast.StmtTraitUseAlias{
                    Position:       yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $3),
                    Trait:          $1.(*TraitMethodRef).Trait,
                    DoubleColonTkn: $1.(*TraitMethodRef).DoubleColonTkn,
                    Method:         $1.(*TraitMethodRef).Method,
                    AsTkn:          $2,
                    Alias: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($3),
                        IdentifierTkn: $3,
                        Value:         $3.Value,
                    },
                }
            }
    |   trait_method_reference T_AS member_modifier identifier_ex
            {
                $$ = &ast.StmtTraitUseAlias{
                    Position:       yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $4),
                    Trait:          $1.(*TraitMethodRef).Trait,
                    DoubleColonTkn: $1.(*TraitMethodRef).DoubleColonTkn,
                    Method:         $1.(*TraitMethodRef).Method,
                    AsTkn:          $2,
                    Modifier:       $3,
                    Alias: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($4),
                        IdentifierTkn: $4,
                        Value:         $4.Value,
                    },
                }
            }
    |   trait_method_reference T_AS member_modifier
            {
                $$ = &ast.StmtTraitUseAlias{
                    Position:       yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Trait:          $1.(*TraitMethodRef).Trait,
                    DoubleColonTkn: $1.(*TraitMethodRef).DoubleColonTkn,
                    Method:         $1.(*TraitMethodRef).Method,
                    AsTkn:          $2,
                    Modifier:       $3,
                }
            }
;

trait_method_reference:
        identifier_ex
            {
                $$ = &TraitMethodRef{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    Method: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        IdentifierTkn: $1,
                        Value:         $1.Value,
                    },
                }
            }
    |   absolute_trait_method_reference
            {
                $$ = $1
            }
;

absolute_trait_method_reference:
        name T_PAAMAYIM_NEKUDOTAYIM identifier_ex
            {
                $$ = &TraitMethodRef{
                    Position: yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $3),
                    Trait:          $1,
                    DoubleColonTkn: $2,
                    Method: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($3),
                        IdentifierTkn: $3,
                        Value:         $3.Value,
                    },
                }
            }
;

method_body:
        ';' /* abstract method */
            {
                $$ = &ast.StmtNop{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    SemiColonTkn: $1,
                }
            }
    |   '{' inner_statement_list '}'
            {
                $$ = &ast.StmtStmtList{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenCurlyBracketTkn:  $1,
                    Stmts:                $2,
                    CloseCurlyBracketTkn: $3,
                }
            }
;

variable_modifiers:
        non_empty_member_modifiers { $$ = $1 }
    |   T_VAR                      { $$ = []ast.Vertex{yylex.(*Parser).builder.NewIdentifier($1)} }
;

method_modifiers:
        /* empty */                { $$ = nil }
    |   non_empty_member_modifiers { $$ = $1 }
;

non_empty_member_modifiers:
        member_modifier                            { $$ = []ast.Vertex{$1} }
    |   non_empty_member_modifiers member_modifier { $$ = append($1, $2) }
;

member_modifier:
        T_PUBLIC                   { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_PROTECTED                { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_PRIVATE                  { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_STATIC                   { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_ABSTRACT                 { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_FINAL                    { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   T_READONLY                 { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
;

property_list:
        property_list ',' property { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
    |   property                   { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
;

property:
        plain_variable backup_doc_comment
            {
                $$ = &ast.StmtProperty{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    Var: &ast.ExprVariable{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        Name: &ast.Identifier{
                            Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                            IdentifierTkn: $1,
                            Value:         $1.Value,
                        },
                    },
                    Expr: nil,
                }
            }
    |   plain_variable '=' expr backup_doc_comment
            {
                $$ = &ast.StmtProperty{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $3),
                    Var: &ast.ExprVariable{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        Name: &ast.Identifier{
                            Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                            IdentifierTkn: $1,
                            Value:         $1.Value,
                        },
                    },
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
;

class_const_list:
        class_const_list ',' class_const_decl { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
    |   class_const_decl                      { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
;

class_const_decl:
        identifier_ex '=' expr backup_doc_comment
            {
                $$ = &ast.StmtConstant{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $3),
                    Name: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        IdentifierTkn: $1,
                        Value:         $1.Value,
                    },
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
;

const_decl:
        identifier '=' expr backup_doc_comment
            {
                $$ = &ast.StmtConstant{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $3),
                    Name: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        IdentifierTkn: $1,
                        Value:         $1.Value,
                    },
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
;

echo_expr_list:
        echo_expr_list ',' echo_expr
            {
                $1.(*ast.StmtEcho).Exprs = append($1.(*ast.StmtEcho).Exprs, $3)
                $1.(*ast.StmtEcho).SeparatorTkns = append($1.(*ast.StmtEcho).SeparatorTkns, $2)

                $$ = $1
            }
    |   echo_expr
            {
                $$ = &ast.StmtEcho{
                    Exprs: []ast.Vertex{$1},
                }
            }
;

echo_expr:
        expr { $$ = $1 }
;

for_exprs:
        /* empty */                  { $$ = &ParserSeparatedList{} }
    |   non_empty_for_exprs          { $$ = $1 }
;

non_empty_for_exprs:
        non_empty_for_exprs ',' expr { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
    |   expr                         { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
;

anonymous_class:
        optional_attributes
        T_CLASS ctor_arguments extends_from implements_list '{' class_statement_list '}'
            { $$ = yylex.(*Parser).builder.NewAnonClass($1, $2, $3, $4, $5, $6, $7, $8) }
;

new_expr:
        T_NEW class_name_reference ctor_arguments
            {
                if $3 != nil {
                    $$ = &ast.ExprNew{
                        Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $3),
                        NewTkn:              $1,
                        Class:               $2,
                        OpenParenthesisTkn:  $3.(*ArgumentList).OpenParenthesisTkn,
                        Args:                $3.(*ArgumentList).Arguments,
                        SeparatorTkns:       $3.(*ArgumentList).SeparatorTkns,
                        CloseParenthesisTkn: $3.(*ArgumentList).CloseParenthesisTkn,
                    }
                } else {
                    $$ = &ast.ExprNew{
                        Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                        NewTkn: $1,
                        Class:  $2,
                    }
                }
            }
    |   T_NEW anonymous_class
            {
                $$ = &ast.ExprNew{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    NewTkn: $1,
                    Class:  $2,
                }
            }
;

expr_list_allow_comma:
        non_empty_expr_list optional_comma
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, nil) }
;

non_empty_expr_list:
        non_empty_expr_list ',' expr { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
    |   expr                         { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
;

match:
        T_MATCH '(' expr ')' '{' match_arm_list '}'
            { $$ = yylex.(*Parser).builder.NewMatch($1, $2, $3, $4, $5, $6, $7) }
;

match_arm_list:
        /* empty */
            { $$ = nil; }
    |   non_empty_match_arm_list optional_comma
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, nil) }
;

non_empty_match_arm_list:
        match_arm
            { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
    |   non_empty_match_arm_list ',' match_arm
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

match_arm:
        expr_list_allow_comma T_DOUBLE_ARROW expr
            { $$ = yylex.(*Parser).builder.NewMatchArm(nil, nil, $1, $2, $3) }
    |   T_DEFAULT optional_comma T_DOUBLE_ARROW expr
            { $$ = yylex.(*Parser).builder.NewMatchArm($1, $2, nil, $3, $4) }
;

expr_without_variable:
        T_LIST '(' array_pair_list ')' '=' expr
            {
                $$ = &ast.ExprAssign{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $6),
                    Var: &ast.ExprList{
                        Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                        ListTkn:         $1,
                        OpenBracketTkn:  $2,
                        Items:           $3.(*ParserSeparatedList).Items,
                        SeparatorTkns:   $3.(*ParserSeparatedList).SeparatorTkns,
                        CloseBracketTkn: $4,
                    },
                    EqualTkn: $5,
                    Expr:     $6,
                }
            }
    |   '[' array_pair_list ']' '=' expr
            {
                $$ = &ast.ExprAssign{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $5),
                    Var: &ast.ExprList{
                        Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                        OpenBracketTkn:  $1,
                        Items:           $2.(*ParserSeparatedList).Items,
                        SeparatorTkns:   $2.(*ParserSeparatedList).SeparatorTkns,
                        CloseBracketTkn: $3,
                    },
                    EqualTkn: $4,
                    Expr:     $5,
                }
            }
    |   variable '=' expr
            {
                $$ = &ast.ExprAssign{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable '=' ampersand expr
            {
                $$ = &ast.ExprAssignReference{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $4),
                    Var:          $1,
                    EqualTkn:     $2,
                    AmpersandTkn: $3,
                    Expr:         $4,
                }
            }
    |   T_CLONE expr
            {
                $$ = &ast.ExprClone{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    CloneTkn: $1,
                    Expr:     $2,
                }
            }
    |   variable T_PLUS_EQUAL expr
            {
                $$ = &ast.ExprAssignPlus{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_MINUS_EQUAL expr
            {
                $$ = &ast.ExprAssignMinus{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_MUL_EQUAL expr
            {
                $$ = &ast.ExprAssignMul{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_POW_EQUAL expr
            {
                $$ = &ast.ExprAssignPow{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_DIV_EQUAL expr
            {
                $$ = &ast.ExprAssignDiv{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_CONCAT_EQUAL expr
            {
                $$ = &ast.ExprAssignConcat{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_MOD_EQUAL expr
            {
                $$ = &ast.ExprAssignMod{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_AND_EQUAL expr
            {
                $$ = &ast.ExprAssignBitwiseAnd{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_OR_EQUAL expr
            {
                $$ = &ast.ExprAssignBitwiseOr{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_XOR_EQUAL expr
            {
                $$ = &ast.ExprAssignBitwiseXor{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_SL_EQUAL expr
            {
                $$ = &ast.ExprAssignShiftLeft{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_SR_EQUAL expr
            {
                $$ = &ast.ExprAssignShiftRight{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_COALESCE_EQUAL expr
            {
                $$ = &ast.ExprAssignCoalesce{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Var:      $1,
                    EqualTkn: $2,
                    Expr:     $3,
                }
            }
    |   variable T_INC
            {
                $$ = &ast.ExprPostInc{
                    Position: yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $2),
                    Var:    $1,
                    IncTkn: $2,
                }
            }
    |   T_INC variable
            {
                $$ = &ast.ExprPreInc{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    IncTkn: $1,
                    Var:    $2,
                }
            }
    |   variable T_DEC
            {
                $$ = &ast.ExprPostDec{
                    Position: yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $2),
                    Var:    $1,
                    DecTkn: $2,
                }
            }
    |   T_DEC variable
            {
                $$ = &ast.ExprPreDec{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    DecTkn: $1,
                    Var:    $2,
                }
            }
    |   expr T_BOOLEAN_OR expr
            {
                $$ = &ast.ExprBinaryBooleanOr{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_BOOLEAN_AND expr
            {
                $$ = &ast.ExprBinaryBooleanAnd{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_LOGICAL_OR expr
            {
                $$ = &ast.ExprBinaryLogicalOr{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_LOGICAL_AND expr
            {
                $$ = &ast.ExprBinaryLogicalAnd{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_LOGICAL_XOR expr
            {
                $$ = &ast.ExprBinaryLogicalXor{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr '|' expr
            {
                $$ = &ast.ExprBinaryBitwiseOr{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_AMPERSAND_NOT_FOLLOWED_BY_VAR_OR_VARARG expr
            {
                $$ = &ast.ExprBinaryBitwiseAnd{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_AMPERSAND_FOLLOWED_BY_VAR_OR_VARARG expr
	    {
	        $$ = &ast.ExprBinaryBitwiseAnd{
	    	     Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
	    	     Left:  $1,
	    	     OpTkn: $2,
	    	     Right: $3,
	        }
	    }
    |   expr '^' expr
            {
                $$ = &ast.ExprBinaryBitwiseXor{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr '.' expr
            {
                $$ = &ast.ExprBinaryConcat{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr '+' expr
            {
                $$ = &ast.ExprBinaryPlus{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr '-' expr
            {
                $$ = &ast.ExprBinaryMinus{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr '*' expr
            {
                $$ = &ast.ExprBinaryMul{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_POW expr
            {
                $$ = &ast.ExprBinaryPow{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr '/' expr
            {
                $$ = &ast.ExprBinaryDiv{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr '%' expr
            {
                $$ = &ast.ExprBinaryMod{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_SL expr
            {
                $$ = &ast.ExprBinaryShiftLeft{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_SR expr
            {
                $$ = &ast.ExprBinaryShiftRight{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   '+' expr %prec T_INC
            {
                $$ = &ast.ExprUnaryPlus{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    PlusTkn: $1,
                    Expr:    $2,
                }
            }
    |   '-' expr %prec T_INC
            {
                $$ = &ast.ExprUnaryMinus{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    MinusTkn: $1,
                    Expr:     $2,
                }
            }
    |   '!' expr
            {
                $$ = &ast.ExprBooleanNot{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    ExclamationTkn: $1,
                    Expr:           $2,
                }
            }
    |   '~' expr
            {
                $$ = &ast.ExprBitwiseNot{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    TildaTkn: $1,
                    Expr:     $2,
                }
            }
    |   expr T_IS_IDENTICAL expr
            {
                $$ = &ast.ExprBinaryIdentical{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_IS_NOT_IDENTICAL expr
            {
                $$ = &ast.ExprBinaryNotIdentical{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_IS_EQUAL expr
            {
                $$ = &ast.ExprBinaryEqual{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_IS_NOT_EQUAL expr
            {
                $$ = &ast.ExprBinaryNotEqual{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr '<' expr
            {
                $$ = &ast.ExprBinarySmaller{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_IS_SMALLER_OR_EQUAL expr
            {
                $$ = &ast.ExprBinarySmallerOrEqual{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr '>' expr
            {
                $$ = &ast.ExprBinaryGreater{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_IS_GREATER_OR_EQUAL expr
            {
                $$ = &ast.ExprBinaryGreaterOrEqual{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_SPACESHIP expr
            {
                $$ = &ast.ExprBinarySpaceship{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   expr T_INSTANCEOF class_name_reference
            {
                $$ = &ast.ExprInstanceOf{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Expr:          $1,
                    InstanceOfTkn: $2,
                    Class:         $3,
                }
            }
    |   '(' expr ')'
            {
                $$ = &ast.ExprBrackets{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenParenthesisTkn:  $1,
                    Expr:                $2,
                    CloseParenthesisTkn: $3,
                }
            }
    |   new_expr
            {
                $$ = $1
            }
    |   match
            {
                $$ = $1
            }
    |   expr '?' expr ':' expr
            {
                $$ = &ast.ExprTernary{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $5),
                    Cond:        $1,
                    QuestionTkn: $2,
                    IfTrue:      $3,
                    ColonTkn:    $4,
                    IfFalse:     $5,
                }
            }
    |   expr '?' ':' expr
            {
                $$ = &ast.ExprTernary{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $4),
                    Cond:        $1,
                    QuestionTkn: $2,
                    ColonTkn:    $3,
                    IfFalse:     $4,
                }
            }
    |   expr T_COALESCE expr
            {
                $$ = &ast.ExprBinaryCoalesce{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Left:  $1,
                    OpTkn: $2,
                    Right: $3,
                }
            }
    |   internal_functions_in_yacc
            {
                $$ = $1
            }
    |   T_INT_CAST expr
            {
                $$ = &ast.ExprCastInt{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    CastTkn: $1,
                    Expr:    $2,
                }
            }
    |   T_DOUBLE_CAST expr
            {
                $$ = &ast.ExprCastDouble{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    CastTkn: $1,
                    Expr:    $2,
                }
            }
    |   T_STRING_CAST expr
            {
                $$ = &ast.ExprCastString{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    CastTkn: $1,
                    Expr:    $2,
                }
            }
    |   T_ARRAY_CAST expr
            {
                $$ = &ast.ExprCastArray{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    CastTkn: $1,
                    Expr:    $2,
                }
            }
    |   T_OBJECT_CAST expr
            {
                $$ = &ast.ExprCastObject{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    CastTkn: $1,
                    Expr:    $2,
                }
            }
    |   T_BOOL_CAST expr
            {
                $$ = &ast.ExprCastBool{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    CastTkn: $1,
                    Expr:    $2,
                }
            }
    |   T_UNSET_CAST expr
            {
                $$ = &ast.ExprCastUnset{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    CastTkn: $1,
                    Expr:    $2,
                }
            }
    |   T_EXIT exit_expr
            {
                exit := &ast.ExprExit{
                    ExitTkn: $1,
                }

                if $2 == nil {
                    exit.Position = yylex.(*Parser).builder.Pos.NewTokenPosition($1)
                } else {
                    exit.Position       = yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2)
                    exit.OpenParenthesisTkn  = $2.(*ast.ExprBrackets).OpenParenthesisTkn
                    exit.Expr                = $2.(*ast.ExprBrackets).Expr
                    exit.CloseParenthesisTkn = $2.(*ast.ExprBrackets).CloseParenthesisTkn
                }

                $$ = exit
            }
    |   '@' expr
            {
                $$ = &ast.ExprErrorSuppress{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    AtTkn: $1,
                    Expr:  $2,
                }
            }
    |   scalar
            {
                $$ = $1
            }
    |   '`' backticks_expr '`'
            {
                $$ = &ast.ExprShellExec{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenBacktickTkn:  $1,
                    Parts:            $2,
                    CloseBacktickTkn: $3,
                }
            }
    |   T_PRINT expr
            {
                $$ = &ast.ExprPrint{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    PrintTkn: $1,
                    Expr:     $2,
                }
            }
    |   T_YIELD
            {
                $$ = &ast.ExprYield{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    YieldTkn: $1,
                }
            }
    |   T_YIELD expr
            {
                $$ = &ast.ExprYield{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    YieldTkn: $1,
                    Val:      $2,
                }
            }
    |   T_YIELD expr T_DOUBLE_ARROW expr
            {
                $$ = &ast.ExprYield{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $4),
                    YieldTkn:       $1,
                    Key:            $2,
                    DoubleArrowTkn: $3,
                    Val:            $4,
                }
            }
    |   T_YIELD_FROM expr
            {
                $$ = &ast.ExprYieldFrom{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    YieldFromTkn: $1,
                    Expr:         $2,
                }
            }
    |   T_THROW expr
            {
                $$ = yylex.(*Parser).builder.NewThrowExpr($1, $2)
            }
    |   attributed_inline_function
            {
                $$ = $1;
            }
    |   T_STATIC attributed_inline_function
            {
                switch n := $2.(type) {
                case *ast.ExprClosure :
                    n.Position = yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2)
                    n.StaticTkn = $1;
                case *ast.ExprArrowFunction :
                    n.Position = yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2)
                    n.StaticTkn = $1;
                };

                $$ = $2
            }
;

attributed_inline_function:
        inline_function            { $$ = $1 }
    |   attributes inline_function
           {
               switch n := $2.(type) {
               case *ast.ExprClosure :
                   n.Position = yylex.(*Parser).builder.Pos.NewNodeListNodePosition($1, $2)
                   n.AttrGroups = $1;
               case *ast.ExprArrowFunction :
                   n.Position = yylex.(*Parser).builder.Pos.NewNodeListNodePosition($1, $2)
                   n.AttrGroups = $1;
               };

               $$ = $2
           }
;

inline_function:
        T_FUNCTION optional_ref backup_doc_comment '(' parameter_list ')' lexical_vars optional_return_type '{' inner_statement_list '}'
            {
                closure := $7.(*ast.ExprClosure)

                closure.Position             = yylex.(*Parser).builder.Pos.NewTokensPosition($1, $11)
                closure.FunctionTkn          = $1
                closure.AmpersandTkn         = $2
                closure.OpenParenthesisTkn   = $4
                closure.Params               = $5.(*ParserSeparatedList).Items
                closure.SeparatorTkns        = $5.(*ParserSeparatedList).SeparatorTkns
                closure.CloseParenthesisTkn  = $6
                closure.ColonTkn             = $8.(*ReturnType).ColonTkn
                closure.ReturnType           = $8.(*ReturnType).Type
                closure.OpenCurlyBracketTkn  = $9
                closure.Stmts                = $10
                closure.CloseCurlyBracketTkn = $11

                $$ = closure
            }
    |   T_FN optional_ref '(' parameter_list ')' optional_return_type backup_doc_comment T_DOUBLE_ARROW expr %prec T_THROW
            {
                $$ = &ast.ExprArrowFunction{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $9),
                    FnTkn:               $1,
                    AmpersandTkn:        $2,
                    OpenParenthesisTkn:  $3,
                    Params:              $4.(*ParserSeparatedList).Items,
                    SeparatorTkns:       $4.(*ParserSeparatedList).SeparatorTkns,
                    CloseParenthesisTkn: $5,
                    ColonTkn:            $6.(*ReturnType).ColonTkn,
                    ReturnType:          $6.(*ReturnType).Type,
                    DoubleArrowTkn:      $8,
                    Expr:                $9,
                }
            }
;

backup_doc_comment:
        /* empty */
;

lexical_vars:
        /* empty */
            { $$ = &ast.ExprClosure{} }
    |   T_USE '(' lexical_var_list ')'
            {
                $$ = &ast.ExprClosure{
                    UseTkn:                 $1,
                    UseOpenParenthesisTkn:  $2,
                    Uses:                   $3.(*ParserSeparatedList).Items,
                    UseSeparatorTkns:       $3.(*ParserSeparatedList).SeparatorTkns,
                    UseCloseParenthesisTkn: $4,
                }
            }
;

lexical_var_list:
       non_empty_lexical_var_list optional_comma   { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, nil) }
;

non_empty_lexical_var_list:
        non_empty_lexical_var_list ',' lexical_var { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
    |   lexical_var                                { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
;

lexical_var:
    plain_variable
            {
                $$ = &ast.ExprClosureUse{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    Var: &ast.ExprVariable{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        Name: &ast.Identifier{
                            Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                            IdentifierTkn: $1,
                            Value:         $1.Value,
                        },
                    },
                }
            }
    |   ampersand plain_variable
            {
                $$ = &ast.ExprClosureUse{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $2),
                    AmpersandTkn: $1,
                    Var: &ast.ExprVariable{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($2),
                        Name: &ast.Identifier{
                            Position: yylex.(*Parser).builder.Pos.NewTokenPosition($2),
                            IdentifierTkn: $2,
                            Value:         $2.Value,
                        },
                    },
                }
            }
;

function_call:
        name argument_list
            {
                $$ = &ast.ExprFunctionCall{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $2),
                    Function:            $1,
                    OpenParenthesisTkn:  $2.(*ArgumentList).OpenParenthesisTkn,
                    Args:                $2.(*ArgumentList).Arguments,
                    SeparatorTkns:       $2.(*ArgumentList).SeparatorTkns,
                    EllipsisTkn:         $2.(*ArgumentList).EllipsisTkn,
                    CloseParenthesisTkn: $2.(*ArgumentList).CloseParenthesisTkn,
                }
            }
    |   class_name_or_var T_PAAMAYIM_NEKUDOTAYIM member_name argument_list
            {
                staticCall := &ast.ExprStaticCall{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $4),
                    Class:               $1,
                    DoubleColonTkn:      $2,
                    Call:                $3,
                    OpenParenthesisTkn:  $4.(*ArgumentList).OpenParenthesisTkn,
                    Args:                $4.(*ArgumentList).Arguments,
                    SeparatorTkns:       $4.(*ArgumentList).SeparatorTkns,
                    EllipsisTkn:         $4.(*ArgumentList).EllipsisTkn,
                    CloseParenthesisTkn: $4.(*ArgumentList).CloseParenthesisTkn,
                }

                if brackets, ok := $3.(*ParserBrackets); ok {
                    staticCall.OpenCurlyBracketTkn  = brackets.OpenBracketTkn
                    staticCall.Call                 = brackets.Child
                    staticCall.CloseCurlyBracketTkn = brackets.CloseBracketTkn
                }

                $$ = staticCall
            }
    |   callable_expr argument_list
            {
                $$ = &ast.ExprFunctionCall{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $2),
                    Function:            $1,
                    OpenParenthesisTkn:  $2.(*ArgumentList).OpenParenthesisTkn,
                    Args:                $2.(*ArgumentList).Arguments,
                    SeparatorTkns:       $2.(*ArgumentList).SeparatorTkns,
                    EllipsisTkn:         $2.(*ArgumentList).EllipsisTkn,
                    CloseParenthesisTkn: $2.(*ArgumentList).CloseParenthesisTkn,
                }
            }
;

class_name_or_var:
         class_name           { $$ = $1 }
    |    fully_dereferencable { $$ = $1 }
;

class_name:
        T_STATIC              { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   name                  { $$ = $1 }
;

class_name_reference:
        class_name            { $$ = $1 }
    |   new_variable          { $$ = $1 }
    |   '(' expr ')'          { $$ = yylex.(*Parser).builder.NewBracket($1, $2, $3) }
;

exit_expr:
        /* empty */           { $$ = nil }
    |   '(' optional_expr ')' { $$ = yylex.(*Parser).builder.NewBracket($1, $2, $3) }
;

backticks_expr:
        /* empty */
            {
                $$ = []ast.Vertex{}
            }
    |   T_ENCAPSED_AND_WHITESPACE
            {
                $$ = []ast.Vertex{
                    &ast.ScalarEncapsedStringPart{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        EncapsedStrTkn: $1,
                        Value:          $1.Value,
                    },
                }
            }
    |   encaps_list
            {
                $$ = $1
            }
;

ctor_arguments:
        /* empty */   { $$ = nil }
    |   argument_list { $$ = $1 }
;

dereferencable_scalar:
    T_ARRAY '(' array_pair_list ')'
            {
                $$ = &ast.ExprArray{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    ArrayTkn:        $1,
                    OpenBracketTkn:  $2,
                    Items:           $3.(*ParserSeparatedList).Items,
                    SeparatorTkns:   $3.(*ParserSeparatedList).SeparatorTkns,
                    CloseBracketTkn: $4,
                }
            }
    |   '[' array_pair_list ']'
            {
                $$ = &ast.ExprArray{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenBracketTkn:  $1,
                    Items:           $2.(*ParserSeparatedList).Items,
                    SeparatorTkns:   $2.(*ParserSeparatedList).SeparatorTkns,
                    CloseBracketTkn: $3,
                }
            }
    |   T_CONSTANT_ENCAPSED_STRING
            {
                $$ = &ast.ScalarString{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    StringTkn: $1,
                    Value:     $1.Value,
                }
            }
    |   '"' encaps_list '"'
            {
                $$ = &ast.ScalarEncapsed{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenQuoteTkn:  $1,
                    Parts:         $2,
                    CloseQuoteTkn: $3,
                }
            }
;

scalar:
        T_LNUMBER
            {
                $$ = &ast.ScalarLnumber{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    NumberTkn: $1,
                    Value:     $1.Value,
                }
            }
    |   T_DNUMBER
            {
                $$ = &ast.ScalarDnumber{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    NumberTkn: $1,
                    Value:     $1.Value,
                }
            }
    |   T_START_HEREDOC T_ENCAPSED_AND_WHITESPACE T_END_HEREDOC
            {
                $$ = &ast.ScalarHeredoc{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenHeredocTkn: $1,
                    Parts: []ast.Vertex{
                        &ast.ScalarEncapsedStringPart{
                            Position: yylex.(*Parser).builder.Pos.NewTokenPosition($2),
                            EncapsedStrTkn: $2,
                            Value:          $2.Value,
                        },
                    },
                    CloseHeredocTkn: $3,
                }
            }
    |   T_START_HEREDOC T_END_HEREDOC
            {
                $$ = &ast.ScalarHeredoc{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $2),
                    OpenHeredocTkn:  $1,
                    CloseHeredocTkn: $2,
                }
            }
    |   T_START_HEREDOC encaps_list T_END_HEREDOC
            {
                $$ = &ast.ScalarHeredoc{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenHeredocTkn:  $1,
                    Parts:           $2,
                    CloseHeredocTkn: $3,
                }
            }
    |   dereferencable_scalar { $$ = $1 }
    |   class_constant        { $$ = $1 }
    |   constant              { $$ = $1 }
;

class_constant:
        class_name_or_var T_PAAMAYIM_NEKUDOTAYIM identifier_ex
            {
                $$ = &ast.ExprClassConstFetch{
                    Position: yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $3),
                    Class:          $1,
                    DoubleColonTkn: $2,
                    Const: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($3),
                        IdentifierTkn: $3,
                        Value:         $3.Value,
                    },
                }
            }
;

constant:
        name                  { $$ = yylex.(*Parser).builder.NewConstFetch($1) }
    |   T_LINE                { $$ = yylex.(*Parser).builder.NewScalarMagicConstant($1) }
    |   T_FILE                { $$ = yylex.(*Parser).builder.NewScalarMagicConstant($1) }
    |   T_DIR                 { $$ = yylex.(*Parser).builder.NewScalarMagicConstant($1) }
    |   T_TRAIT_C             { $$ = yylex.(*Parser).builder.NewScalarMagicConstant($1) }
    |   T_METHOD_C            { $$ = yylex.(*Parser).builder.NewScalarMagicConstant($1) }
    |   T_FUNC_C              { $$ = yylex.(*Parser).builder.NewScalarMagicConstant($1) }
    |   T_NS_C                { $$ = yylex.(*Parser).builder.NewScalarMagicConstant($1) }
    |   T_CLASS_C             { $$ = yylex.(*Parser).builder.NewScalarMagicConstant($1) }
;

expr:
        variable              { $$ = $1 }
    |   expr_without_variable { $$ = $1 }
;

optional_expr:
        /* empty */           { $$ = nil }
    |   expr                  { $$ = $1 }
;

fully_dereferencable:
        variable              { $$ = $1 }
    |   '(' expr ')'          { $$ = yylex.(*Parser).builder.NewBracket($1, $2, $3) }
    |   dereferencable_scalar { $$ = $1 }
    | class_constant          { $$ = $1 }
;

array_object_dereferencable:
      fully_dereferencable    { $$ = $1 }
    | constant                { $$ = $1 }
;

callable_expr:
        callable_variable     { $$ = $1 }
    |   '(' expr ')'          { $$ = yylex.(*Parser).builder.NewBracket($1, $2, $3) }
    |   dereferencable_scalar { $$ = $1 }
;

callable_variable:
        simple_variable
            { $$ = $1 }
    |   array_object_dereferencable '[' optional_expr ']'
            {
                $$ = &ast.ExprArrayDimFetch{
                    Position: yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $4),
                    Var:             $1,
                    OpenBracketTkn:  $2,
                    Dim:             $3,
                    CloseBracketTkn: $4,
                }
            }
    |   array_object_dereferencable '{' expr '}'
            {
                yylex.(*Parser).Error("Array and string offset access syntax with curly braces is no longer supported")

                $$ = &ast.ExprArrayDimFetch{
                    Position: yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $4),
                    Var:             $1,
                    OpenBracketTkn:  $2,
                    Dim:             $3,
                    CloseBracketTkn: $4,
                }
            }
    |   array_object_dereferencable T_OBJECT_OPERATOR property_name argument_list
            { $$ = yylex.(*Parser).builder.NewMethodCall($1, $2, $3, $4) }
    |   array_object_dereferencable T_NULLSAFE_OBJECT_OPERATOR property_name argument_list
            { $$ = yylex.(*Parser).builder.NewNullsafeMethodCall($1, $2, $3, $4) }
    |   function_call
            { $$ = $1 }
;

variable:
        callable_variable
            { $$ = $1 }
    |   static_member
            { $$ = $1 }
    |   array_object_dereferencable T_OBJECT_OPERATOR property_name
            { $$ = yylex.(*Parser).builder.NewPropertyFetch($1, $2, $3) }
    |   array_object_dereferencable T_NULLSAFE_OBJECT_OPERATOR property_name
            { $$ = yylex.(*Parser).builder.NewNullsafePropertyFetch($1, $2, $3) }
;

simple_variable:
        plain_variable
            {
                $$ = &ast.ExprVariable{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    Name: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        IdentifierTkn: $1,
                        Value:         $1.Value,
                    },
                }
            }
    |   '$' '{' expr '}'
            {
                $$ = &ast.ExprVariable{
                    Position:             yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    DollarTkn:            $1,
                    OpenCurlyBracketTkn:  $2,
                    Name:                 $3,
                    CloseCurlyBracketTkn: $4,
                }
            }
    |   '$' simple_variable
            {
                $$ = &ast.ExprVariable{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    DollarTkn: $1,
                    Name:      $2,
                }
            }
;

static_member:
        class_name_or_var T_PAAMAYIM_NEKUDOTAYIM simple_variable
            {
                $$ = &ast.ExprStaticPropertyFetch{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Class:          $1,
                    DoubleColonTkn: $2,
                    Prop:           $3,
                }
            }
;

new_variable:
        simple_variable
            {
                $$ = $1
            }
    |   new_variable '[' optional_expr ']'
            {
                $$ = &ast.ExprArrayDimFetch{
                    Position: yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $4),
                    Var:             $1,
                    OpenBracketTkn:  $2,
                    Dim:             $3,
                    CloseBracketTkn: $4,
                }
            }
    |   new_variable '{' expr '}'
            {
                yylex.(*Parser).Error("Array and string offset access syntax with curly braces is no longer supported")

                $$ = &ast.ExprArrayDimFetch{
                    Position: yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $4),
                    Var:             $1,
                    OpenBracketTkn:  $2,
                    Dim:             $3,
                    CloseBracketTkn: $4,
                }
            }
    |   new_variable T_OBJECT_OPERATOR property_name
            {
                $$ = yylex.(*Parser).builder.NewPropertyFetch($1, $2, $3)
            }
    |   new_variable T_NULLSAFE_OBJECT_OPERATOR property_name
           {
               $$ = yylex.(*Parser).builder.NewNullsafePropertyFetch($1, $2, $3)
           }
    |   class_name T_PAAMAYIM_NEKUDOTAYIM simple_variable
            {
                $$ = &ast.ExprStaticPropertyFetch{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Class:          $1,
                    DoubleColonTkn: $2,
                    Prop:           $3,
                }
            }
    |   new_variable T_PAAMAYIM_NEKUDOTAYIM simple_variable
            {
                $$ = &ast.ExprStaticPropertyFetch{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Class:          $1,
                    DoubleColonTkn: $2,
                    Prop:           $3,
                }
            }
;

member_name:
        identifier_ex      { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   '{' expr '}'    { $$ = yylex.(*Parser).builder.NewBracket($1, $2, $3) }
    |   simple_variable { $$ = $1 }
;

property_name:
        identifier      { $$ = yylex.(*Parser).builder.NewIdentifier($1) }
    |   '{' expr '}'    { $$ = yylex.(*Parser).builder.NewBracket($1, $2, $3) }
    |   simple_variable { $$ = $1 }
;

array_pair_list:
        non_empty_array_pair_list
            {
                pairList := $1.(*ParserSeparatedList)
                fistPair := pairList.Items[0].(*ast.ExprArrayItem)

                if fistPair.Key == nil && fistPair.Val == nil && len(pairList.Items) == 1 {
                    pairList.Items = nil
                }

                $$ = $1
            }
;

possible_array_pair:
        /* empty */ { $$ = &ast.ExprArrayItem{} }
    |   array_pair  { $$ = $1}
;

non_empty_array_pair_list:
        non_empty_array_pair_list ',' possible_array_pair
            { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
    |   possible_array_pair
            { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
;

array_pair:
        expr T_DOUBLE_ARROW expr
            {
                $$ = &ast.ExprArrayItem{
                    Position: yylex.(*Parser).builder.Pos.NewNodesPosition($1, $3),
                    Key:            $1,
                    DoubleArrowTkn: $2,
                    Val:            $3,
                }
            }
    |   expr
            {
                $$ = &ast.ExprArrayItem{
                    Position: yylex.(*Parser).builder.Pos.NewNodePosition($1),
                    Val: $1,
                }
            }
    |   expr T_DOUBLE_ARROW T_AMPERSAND_FOLLOWED_BY_VAR_OR_VARARG variable
            {
                $$ = &ast.ExprArrayItem{
                    Position:       yylex.(*Parser).builder.Pos.NewNodesPosition($1, $4),
                    Key:            $1,
                    DoubleArrowTkn: $2,
                    AmpersandTkn:   $3,
                    Val:            $4,
                }
            }
    |   T_AMPERSAND_FOLLOWED_BY_VAR_OR_VARARG variable
            {
                $$ = &ast.ExprArrayItem{
                    Position:     yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    AmpersandTkn: $1,
                    Val:          $2,
                }
            }
    |   T_ELLIPSIS expr
            {
                $$ = &ast.ExprArrayItem{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    EllipsisTkn: $1,
                    Val:         $2,
                }
            }
    |   expr T_DOUBLE_ARROW T_LIST '(' array_pair_list ')'
            {
                $$ = &ast.ExprArrayItem{
                    Position: yylex.(*Parser).builder.Pos.NewNodeTokenPosition($1, $6),
                    Key:            $1,
                    DoubleArrowTkn: $2,
                    Val: &ast.ExprList{
                        Position: yylex.(*Parser).builder.Pos.NewTokensPosition($3, $6),
                        ListTkn:         $3,
                        OpenBracketTkn:  $4,
                        Items:           $5.(*ParserSeparatedList).Items,
                        SeparatorTkns:   $5.(*ParserSeparatedList).SeparatorTkns,
                        CloseBracketTkn: $6,
                    },
                }
            }
    |   T_LIST '(' array_pair_list ')'
            {
                $$ = &ast.ExprArrayItem{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    Val: &ast.ExprList{
                        Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                        ListTkn:         $1,
                        OpenBracketTkn:  $2,
                        Items:           $3.(*ParserSeparatedList).Items,
                        SeparatorTkns:   $3.(*ParserSeparatedList).SeparatorTkns,
                        CloseBracketTkn: $4,
                    },
                }
            }
;

encaps_list:
        encaps_list encaps_var
            {
                $$ = append($1, $2)
            }
    |   encaps_list T_ENCAPSED_AND_WHITESPACE
            {
                $$ = append(
                    $1,
                    &ast.ScalarEncapsedStringPart{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($2),
                        EncapsedStrTkn: $2,
                        Value:          $2.Value,
                    },
                )
            }
    |   encaps_var
            {
                $$ = []ast.Vertex{$1}
            }
    |   T_ENCAPSED_AND_WHITESPACE encaps_var
            {
                $$ = []ast.Vertex{
                    &ast.ScalarEncapsedStringPart{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        EncapsedStrTkn: $1,
                        Value:          $1.Value,
                    },
                    $2,
                }
            }
;

encaps_var:
        plain_variable
            {
                $$ = &ast.ExprVariable{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    Name: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        IdentifierTkn: $1,
                        Value:         $1.Value,
                    },
                }
            }
    |   plain_variable '[' encaps_var_offset ']'
            {
                $$ = &ast.ExprArrayDimFetch{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    Var: &ast.ExprVariable{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        Name: &ast.Identifier{
                            Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                            IdentifierTkn: $1,
                            Value:         $1.Value,
                        },
                    },
                    OpenBracketTkn:  $2,
                    Dim:             $3,
                    CloseBracketTkn: $4,
                }
            }
    |   plain_variable T_OBJECT_OPERATOR identifier
            {
                $$ = yylex.(*Parser).builder.NewPropertyFetchFromTokens($1, $2, $3)
            }
    |   plain_variable T_NULLSAFE_OBJECT_OPERATOR identifier
            {
                $$ = yylex.(*Parser).builder.NewNullsafePropertyFetchFromTokens($1, $2, $3)
            }
    |   T_DOLLAR_OPEN_CURLY_BRACES expr '}'
            {
                $$ = &ast.ScalarEncapsedStringVar{
                    Position:                  yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    DollarOpenCurlyBracketTkn: $1,
                    Name:                      $2,
                    CloseCurlyBracketTkn:      $3,
                }
            }
    |   T_DOLLAR_OPEN_CURLY_BRACES T_STRING_VARNAME '}'
            {
                $$ = &ast.ScalarEncapsedStringVar{
                    Position:                  yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    DollarOpenCurlyBracketTkn: $1,
                    Name: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($2),
                        IdentifierTkn: $2,
                        Value:         $2.Value,
                    },
                    CloseCurlyBracketTkn: $3,
                }
            }
    |   T_DOLLAR_OPEN_CURLY_BRACES T_STRING_VARNAME '[' expr ']' '}'
            {
                $$ = &ast.ScalarEncapsedStringVar{
                    Position:                  yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    DollarOpenCurlyBracketTkn: $1,
                    Name: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($2),
                        IdentifierTkn: $2,
                        Value:         $2.Value,
                    },
                    OpenSquareBracketTkn:  $3,
                    Dim:                   $4,
                    CloseSquareBracketTkn: $5,
                    CloseCurlyBracketTkn:  $6,
                }
            }
    |   T_CURLY_OPEN variable '}'
            {
                $$ = &ast.ScalarEncapsedStringBrackets{
                    Position:             yylex.(*Parser).builder.Pos.NewTokensPosition($1, $3),
                    OpenCurlyBracketTkn:  $1,
                    Var:                  $2,
                    CloseCurlyBracketTkn: $3,
                }
            }
;

encaps_var_offset:
        identifier
            {
                $$ = &ast.ScalarString{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    StringTkn: $1,
                    Value:     $1.Value,
                }
            }
    |   T_NUM_STRING
            {
                // TODO: add option to handle 64 bit integer
                if _, err := strconv.Atoi(string($1.Value)); err == nil {
                    $$ = &ast.ScalarLnumber{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        NumberTkn: $1,
                        Value:     $1.Value,
                    }
                } else {
                    $$ = &ast.ScalarString{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        StringTkn: $1,
                        Value:     $1.Value,
                    }
                }
            }
    |   '-' T_NUM_STRING
            {
                _, err := strconv.Atoi(string($2.Value));
                isInt := err == nil

                if isInt {
                    $$ = &ast.ExprUnaryMinus{
                        Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $2),
                        MinusTkn: $1,
                        Expr: &ast.ScalarLnumber{
                            Position: yylex.(*Parser).builder.Pos.NewTokenPosition($2),
                            NumberTkn: $2,
                            Value:     $2.Value,
                        },
                    }
                } else {
                    $$ = &ast.ScalarString{
                        Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $2),
                        MinusTkn:  $1,
                        StringTkn: $2,
                        Value:     append([]byte("-"), $2.Value...),
                    }
                }
            }
    |   plain_variable
            {
                $$ = &ast.ExprVariable{
                    Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                    Name: &ast.Identifier{
                        Position: yylex.(*Parser).builder.Pos.NewTokenPosition($1),
                        IdentifierTkn: $1,
                        Value:         $1.Value,
                    },
                }
            }
;

internal_functions_in_yacc:
        T_ISSET '(' isset_variables optional_comma ')'
            {
                if $4 != nil {
                    $3.(*ParserSeparatedList).SeparatorTkns = append($3.(*ParserSeparatedList).SeparatorTkns, $4)
                }

                $$ = &ast.ExprIsset{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $5),
                    IssetTkn:            $1,
                    OpenParenthesisTkn:  $2,
                    Vars:                $3.(*ParserSeparatedList).Items,
                    SeparatorTkns:       $3.(*ParserSeparatedList).SeparatorTkns,
                    CloseParenthesisTkn: $5,
                }
            }
    |   T_EMPTY '(' expr ')'
            {
                $$ = &ast.ExprEmpty{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    EmptyTkn:            $1,
                    OpenParenthesisTkn:  $2,
                    Expr:                $3,
                    CloseParenthesisTkn: $4,
                }
            }
    |   T_INCLUDE expr
            {
                $$ = &ast.ExprInclude{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    IncludeTkn: $1,
                    Expr:       $2,
                }
            }
    |   T_INCLUDE_ONCE expr
            {
                $$ = &ast.ExprIncludeOnce{
                    Position:       yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    IncludeOnceTkn: $1,
                    Expr:           $2,
                }
            }
    |   T_EVAL '(' expr ')'
            {
                $$ = &ast.ExprEval{
                    Position: yylex.(*Parser).builder.Pos.NewTokensPosition($1, $4),
                    EvalTkn:             $1,
                    OpenParenthesisTkn:  $2,
                    Expr:                $3,
                    CloseParenthesisTkn: $4,
                }
            }
    |   T_REQUIRE expr
            {
                $$ = &ast.ExprRequire{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    RequireTkn: $1,
                    Expr:       $2,
                }
            }
    |   T_REQUIRE_ONCE expr
            {
                $$ = &ast.ExprRequireOnce{
                    Position: yylex.(*Parser).builder.Pos.NewTokenNodePosition($1, $2),
                    RequireOnceTkn: $1,
                    Expr:           $2,
                }
            }
;

isset_variables:
        isset_variable                     { $$ = yylex.(*Parser).builder.NewSeparatedList($1) }
    |   isset_variables ',' isset_variable { $$ = yylex.(*Parser).builder.AppendToSeparatedList($1, $2, $3) }
;

isset_variable:
        expr                               { $$ = $1 }
;

/////////////////////////////////////////////////////////////////////////

%%