On 2018-05-08 04:03, Vlad Vladov wrote:
Good day,
I am interested in contributing to the project. Is there anything I can
help with?
Hi Vlad,
Bison/Yacc has an annoying limitation. When you call yyparse, it parses
the entire grammar down to the start symbol.
Sometimes you just want to parse a subtree of the grammar.
Like say you have a full programming language grammar, and you want to
provide a function to parse regular expressions (which are in that
grammar, represented as a "regex" symbol).
Currently, some ugly hack has to be used, like the insertion of a
"secret token" which is recognized by the top-level production.
The parser generator could just automate this. Suppose we could give a
list of additional starts:
%start regex /* additional comma separated non-terminals listed here
*/
then we have a yyparse_regex(...) entry point we just call to parse a
regex. No programmer-visible secret tokens or anything of the sort.
(All the yyparse_* functions have the same arg signature; they probably
just do some special setup and recurse into yyparse.)
Cheers ...
