error tolerant parsing

php5/lexer.go

@@ -7,16 +7,26 @@ import (
 
 	"github.com/cznic/golex/lex"
 
+	"github.com/z7zmey/php-parser/errors"
 	"github.com/z7zmey/php-parser/scanner"
 	"github.com/z7zmey/php-parser/token"
 )
 
 type lexer struct {
 	scanner.Lexer
+	lastToken *token.Token
+	errors    []*errors.Error
 }
 
 func (l *lexer) Lex(lval *yySymType) int {
-	return l.Lexer.Lex(lval)
+	t := l.Lexer.Lex(lval)
+	l.lastToken = &lval.token
+
+	return t
+}
+
+func (l *lexer) Error(msg string) {
+	l.errors = append(l.errors, errors.NewError(msg, *l.lastToken))
 }
 
 func (lval *yySymType) Token(t token.Token) {
@@ -30,12 +40,16 @@ func newLexer(src io.Reader, fName string) *lexer {
 		panic(err)
 	}
 
+	scanner := scanner.Lexer{
+		Lexer:         lx,
+		StateStack:    []int{0},
+		PhpDocComment: "",
+		Comments:      nil,
+	}
+
 	return &lexer{
-		scanner.Lexer{
-			Lexer:         lx,
-			StateStack:    []int{0},
-			PhpDocComment: "",
-			Comments:      nil,
-		},
+		scanner,
+		nil,
+		nil,
 	}
 }

php5/parser.go

@@ -4,6 +4,7 @@ package php5
 import (
 	"io"
 
+	"github.com/z7zmey/php-parser/errors"
 	"github.com/z7zmey/php-parser/node/expr"
 
 	"github.com/z7zmey/php-parser/comment"
@@ -21,15 +22,17 @@ var positionBuilder position.Builder
 var parentNode node.Node
 
 // Parse the php5 parser entrypoint
-func Parse(src io.Reader, fName string) (node.Node, comment.Comments, position.Positions) {
+func Parse(src io.Reader, fName string) (node.Node, comment.Comments, position.Positions, []*errors.Error) {
 	yyDebug = 0
 	yyErrorVerbose = true
 	rootnode = stmt.NewStmtList([]node.Node{}) //reset
 	comments = comment.Comments{}
 	positions = position.Positions{}
 	positionBuilder = position.Builder{Positions: &positions}
-	yyParse(newLexer(src, fName))
-	return rootnode, comments, positions
+
+	lexer := newLexer(src, fName)
+	yyParse(lexer)
+	return rootnode, comments, positions, lexer.errors
 }
 
 // ListGetFirstNodeComments returns comments of a first node in the list

php5/php5.y

@@ -239,7 +239,12 @@ start:
 ;
 
 top_statement_list:
-        top_statement_list top_statement                { $$ = append($1, $2) }
+        top_statement_list top_statement
+            {
+                if $2 != nil {
+                    $$ = append($1, $2)
+                }
+            }
     |   /* empty */                                     { $$ = []node.Node{} }
 ;
 
@@ -261,7 +266,12 @@ namespace_name:
 ;
 
 top_statement:
-        statement
+        error
+            {
+                // error
+                $$ = nil
+            }
+    |   statement
             { $$ = $1 }
     |   function_declaration_statement
             { $$ = $1 }
@@ -534,14 +544,23 @@ constant_declaration:
 
 inner_statement_list:
         inner_statement_list inner_statement
-            { $$ = append($1, $2) }
+            {
+                if $2 != nil {
+                    $$ = append($1, $2)
+                }
+            }
     |   /* empty */
             { $$ = []node.Node{} }
 ;
 
 
 inner_statement:
-        statement
+        error
+            {
+                // error
+                $$ = nil
+            }
+    |   statement
             { $$ = $1 }
     |   function_declaration_statement
             { $$ = $1 }