Initialize NodeVisitor with default grammar

erikrose / parsimonious

The fastest pure-Python PEG parser I can muster

MIT License

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Initialize NodeVisitor with default grammar #223

Closed thehappycheese closed 2 years ago

thehappycheese commented 2 years ago

Proposal to allow NodeVisitor to be initialized using a default grammar object. Old behaviour still works.

added __init__ to NodeVisitor which accepts a default grammar
updated README example to use the default grammar initialization method, although perhaps the example needs to show both methods now?

For your consideration / comment. Not sure if I should have raised an issue to discuss first? Many thanks to you and other contributors for great package :)

thehappycheese commented 2 years ago

Actually now I am reading RuleDecoratorMeta and I can see how a grammar passed into NodeVisitor.__init__ would just replace anything set up in NodeVisitor.__new__ ... I have probably jumped the gun creating a pull request.

It feels like NodeVisitor.__init__ should accept a default grammar and @rule annotations should extend / overwrite that. But if the logic in __new__ were moved to __init__ then inheritance / mro becomes a problem...