bootpeg 0.6.0

bootpeg – the bootstrapping PEG parser

> Some people, when confronted with a problem, think “I know, I’ll use regular expressions.” Now they have two problems.

bootpeg is a PEG parser for creating parsers – including itself. By default, it supports a modified EBNF with actions akin to PEP 617.

>>> # recreate the bootpeg parser from itself
>>> from bootpeg.api import import_parser, PikaActions
>>> from bootpeg.grammars import bpeg
>>> parse_bpeg = bpeg.parse
>>> for _ in range(5):
...     parse_bpeg = import_parser(
...         bpeg.__name__, actions=PikaActions, dialect=parse_bpeg
...     )

Unlike most other Python PEG parsers which are top-down parsers, bootpeg provides a bottom-up Pika parser: it handles left-recursive grammars natively, allows recovering partial parse results, and is guaranteed to run in linear time. Like any PEG parser, bootpeg automatically creates unambiguous grammars, supports infinite lookahead, and allows to express grammars comfortably.

• Native support for left-recursion and left-associativity.

• Builtin error reporting covering multiple failures.

• Automatic parser generation from a multitude of meta-grammars.

This makes it straightforward to implement your own custom grammars without worrying about their implementation. To get started using or contributing to bootpeg, head straight to the bootpeg documentation.

Do I need a bigger boot?

> Some people, when confronted with a problem, think “I know, I’ll use self-writing parsers.” Now they have recursive problems.

If you need a battle-hardened, production ready parser suite then pyparsing should be your first choice. If you are the choosy type, make it your second choice as well.

Pick bootpeg when you need safe left-recursion and self-parsing. It will never bite off your left peg via infinite recursion. It will take care of itself and all its grammars to make you happy. bootpeg is the friend you need when you know bootpeg is the friend you need.

Well, eventually it will be; bootpeg is still a cute little puppy. Don’t let it lift too heavy. So far it is only lifting itself.