php-parser/parser.y

%{
package main

import (
  "bytes"
  "fmt"
  "os"
  "io"
)

type node struct {
  name string
  children []node
}

func (n node) String() string {
  buf := new(bytes.Buffer)
  n.print(buf, " ")
  return buf.String()
}

func (n node) print(out io.Writer, indent string) {
  fmt.Fprintf(out, "\n%v%v", indent, n.name)
  for _, nn := range n.children { nn.print(out, indent + "  ") }
}

func Node(name string) node { return node{name: name} }
func (n node) append(nn...node) node { n.children = append(n.children, nn...); return n }

%}

%union{
    node node
    token string
}

%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
%left '?' ':'
%right T_COALESCE
%left T_BOOLEAN_OR
%left T_BOOLEAN_AND
%left '|'
%left '^'
%left '&'
%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 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_ELSEIF
%left T_ELSE
%left T_ENDIF
%right T_STATIC T_ABSTRACT T_FINAL T_PRIVATE T_PROTECTED T_PUBLIC

%token T_EXIT
%token T_IF
%token T_LNUMBER
%token T_DNUMBER
%token T_STRING
%token T_STRING_VARNAME
%token T_VARIABLE
%token T_NUM_STRING
%token T_INLINE_HTML
%token T_CHARACTER
%token T_BAD_CHARACTER
%token T_ENCAPSED_AND_WHITESPACE
%token T_CONSTANT_ENCAPSED_STRING
%token T_ECHO
%token T_DO
%token T_WHILE
%token T_ENDWHILE
%token T_FOR
%token T_ENDFOR
%token T_FOREACH
%token T_ENDFOREACH
%token T_DECLARE
%token T_ENDDECLARE
%token T_AS
%token T_SWITCH
%token T_ENDSWITCH
%token T_CASE
%token T_DEFAULT
%token T_BREAK
%token T_CONTINUE
%token T_GOTO
%token T_FUNCTION
%token T_CONST
%token T_RETURN
%token T_TRY
%token T_CATCH
%token T_FINALLY
%token T_THROW
%token T_USE
%token T_INSTEADOF
%token T_GLOBAL
%token T_VAR
%token T_UNSET
%token T_ISSET
%token T_EMPTY
%token T_HALT_COMPILER
%token T_CLASS
%token T_TRAIT
%token T_INTERFACE
%token T_EXTENDS
%token T_IMPLEMENTS
%token T_OBJECT_OPERATOR
%token T_DOUBLE_ARROW
%token T_LIST
%token T_ARRAY
%token T_CALLABLE
%token T_CLASS_C
%token T_TRAIT_C
%token T_METHOD_C
%token T_FUNC_C
%token T_LINE
%token T_FILE
%token T_COMMENT
%token T_DOC_COMMENT
%token T_OPEN_TAG
%token T_OPEN_TAG_WITH_ECHO
%token T_CLOSE_TAG
%token T_WHITESPACE
%token T_START_HEREDOC
%token T_END_HEREDOC
%token T_DOLLAR_OPEN_CURLY_BRACES
%token T_CURLY_OPEN
%token T_PAAMAYIM_NEKUDOTAYIM
%token T_NAMESPACE
%token T_NS_C
%token T_DIR
%token T_NS_SEPARATOR
%token T_ELLIPSIS

%type <node> identifier


%%

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

start:
    identifier  { fmt.Println($1) }
;

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

semi_reserved:
        reserved_non_modifiers
    | T_STATIC | T_ABSTRACT | T_FINAL | T_PRIVATE | T_PROTECTED | T_PUBLIC
;

identifier:
        T_STRING { $$ = Node("identifier") }
    |   semi_reserved  { $$ = Node("reserved") }
;

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

%%

const src = `<?
class
`

func main() {
  yyDebug        = 0
  yyErrorVerbose = true
  l := newLexer(bytes.NewBufferString(src), os.Stdout, "file.name")
  yyParse(l)
}