finesse.script.memoize module

Memoize wrappers for the parser.

Based on https://github.com/we-like-parsers/pegen/blob/main/story5/memo.py by Guido van Rossum.

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finesse.script.memoize.memoize(func)[source]

Memoize a parsing method.

The functon must be a method on a class deriving from Parser. The method must have either no arguments or a single argument that is an int or str (the latter being the case for expect()). It must return either None or an object that is not modified (at least not while we’re parsing). We memoize positive and negative outcomes per input position. The function is expected to move the input position iff it returns a not- None value. The memo is structured as a dict of dict, the outer dict indexed by input position, the inner by function and arguments.

finesse.script.memoize.memoize_left_rec(func)[source]

Memoize a left-recursive parsing method.

This is similar to @memoize but loops until no longer parse is obtained. Inspired by https://github.com/PhilippeSigaud/Pegged/wiki/Left-Recursion