JSGLR seems to fails to apply the rejection of line 14 of the following grammar applied to the input “a”; the C sglr does it right. The problem does not occur for the reverse rejection.
Sebastian

definition
module Helper
exports

syntax %% Lexeme
-> N {cons(“AorB”)}
-> N {cons(“Any”)}

lexical syntax
“a” -> AorB
“b” -> AorB
[A-Za-z] -> Any

ReservedId -> VarId {reject}

%% VarId -> ReservedId {reject}

module Main
imports Helper

exports
start-symbols
S

syntax %% LexedDocument
N “\n” -> S {cons(“S”)}

Submitted on 8 February 2011 at 09:00

But ReservedId is not defined in this example grammar? Also, did you test if it was the QVarId injection in your original grammar that triggered the problem? You have a similar injection (to N) here.

right. The fixed grammar follows, the problem remains the same. Removing any indirection from the above grammar seems to remedy the ambiguity.

definition
module Helper
exports

syntax %% Lexeme
  <AorB-LEX>  -> N {cons("AorB")}
  <Any-LEX>   -> N {cons("Any")}

lexical syntax
  "a" -> AorB
  "b" -> AorB
  [A-Za-z] -> Any

  AorB -> Any {reject}

%% Any -> AorB {reject}

module Main
imports Helper

exports
start-symbols
S

syntax %% LexedDocument
  N "\n" -> S {cons("S")}