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