[PoC] Intoroduce parameterizing rules with conditional statement #418
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I would like to propose a new grammar in this PR.
I believe that more parameterizing rules can handle more abstract rules if we can switch between rules and actions that are expanded by conditions in order to make rules common.
DesignDoc: https://gist.github.com/ydah/62008655a6f6c3118ab01134dc91da6f
Syntax is as follows:
%if
and% endif
.Motivation
I believe it will solve the problem mentioned in the article below with the tight coupling with Lexer "to disable certain generation rules under certain conditions" and I would like to propose this feature to solve this problem.
https://yui-knk.hatenablog.com/entry/2023/04/04/190413
We can trace the RHS to f_args > args_tail > args_forward, where f_args is the RHS of both the lambda argument (f_larglist) and the method definition argument (f_arglist).
So if we can switch between RHS and actions by passing parameters, we can break up the Lexer/Parser coupling here.