brm 0.2.1

Bicycle Repair Man - Rewrite Python Sources

Bicycle Repair Man

Rewrite python sources, highly experimental

How?

BRM is based on tokens which can be manipulated easily. Like an ast.NodeTransformer, we offer brm.TokenTransformer. TokenTransformer can do a lot of things starting from registering a new token (via register_{TOK_NAME} functions) to finding and replacing token patterns with parser rules.

!!! This project is highly experimental and has tons of bugs !!

Examples

Simple Patterns

from brm import TokenTransformer, pattern

class OperatorTransformer(TokenTransformer):

    @pattern("number", "plus", "number")
    def plus_to_minus(self, lhs, operator, rhs):
        operator = operator._replace(string="-")
        return lhs, operator, rhs

opt = OperatorTransformer()
assert opt.transform("2 + 2") == "2 - 2"

Custom Tokens and New Syntaxes

from brm import TokenTransformer, pattern

class SquareRoot(TokenTransformer):

    def register_squareroot(self):
        return "√"

    @pattern("squareroot", "number")
    def remove_varprefix(self, sr, number):
        return self.quick_tokenize(f"int({number.string} ** 0.5)")

sqr = SquareRoot()
assert eval(sqr.transform("√9")) == 3