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Enhance context output of UnrecognizedToken exception

Open ohader opened this issue 5 years ago • 0 comments

Grammar

%pragma		parser.lookahead 	0
%skip		space				\s
%token a	a+
%token b	b+
%token c	c+
#root:
    ( <a> | <b> | <c> )*

Source

a
b
c
d

Results

Parsing above scenario leads to expected exception, since lexeme d is not defined in grammar. In thrown UnrecognizedToken

  • line & column can be enhanced
  • (helpful) position pointer can be adjusted
Hoa\Compiler\Exception\UnrecognizedToken: Unrecognized token "d" at line 1 and column 7:
a
b
c
d
      ↑ in /Users/olly/Development/Packages/fluid-compiler/vendor/hoa/compiler/Llk/Lexer.php on line 1

With adjustments

Hoa\Compiler\Exception\UnrecognizedToken: Unrecognized token "d" at line 4 and column 1:
a
b
c
d
↑ in /Users/olly/Development/Packages/fluid-compiler/vendor/hoa/compiler/Llk/Lexer.php on line 1

ohader avatar Oct 06 '20 09:10 ohader