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jison

Handling clike comments in Jison

I'm writing a compiler of clike language in JS using Jison as an lexer/parser generator with angular frontend. I nearly got the result I expected, but there is one thing that is puzzling me - how to make Jison ignore comments (both /* block */ and // line)?

Is there any easy way to achieve it? Keeping in mind that the comment can potentially be inserted in the middle of any statement/expression?

Solution

  • You ignore comments the same way you ignore whitespace: with a lexer rule that has no action.

    For example:

    \s+                                   /* IGNORE */
"//".*                                /* IGNORE */
[/][*][^*]*[*]+([^/*][^*]*[*]+)*[/]   /* IGNORE */

    The first line ignores whitespace. The second ignores single-line comments. And the third ignores block comments.