dagit/happy-plus-alex — pull request #1 by leepike (2014-04-10 15:59:13+00:00)
Title: Have lexer report the position at which lexing fails.

Dagit: your example was very helpful!

Here's a pull request that is slightly more general: it shows how to get position errors for the lexer as well. (In your example, you just get a string error from the lexer. Users might be interested get position info for both the lexer and parser.)