pgpc 0.0.2

A Python Generator based Parser Combinator library

PGPC

Overview

PGPC is a parser combinator library. Its name is an acronym, and it stands for Python Generator based Parser Combinator library.

The library was heavily influenced by the Parsec monadic parser combinator library, so the transition from Parsec (and other parser combinators) to PGPC should be more or less easy.

The original idea of the library is emulating the do-notation with the yield Python keyword.

Quick start

The @topology decorator over a function allows the yield keyword work with parsers in a do-notation-like fashion:

from pgpc.scanner import TextScanner
from pgpc.parser import Parser, topology, char, position, content


@topology
def hello(value: str):
    start = yield position()

    for c in value:
        yield char(c)

    end = yield position()
    source = yield content()

    return f"Parsed {source[start.offset:end.offset]} which started at {start} and ended at {end}"


if __name__ == '__main__':
    text = "HELLO"
    
    par: Parser[str] = hello(text)
    
    result = par(TextScanner(text))
    
    print(result)