Valf implementation spec (valf is not written, yet!)

valf_demo.py

import valf

class Grammar(valf.Grammar):
    class Terminals:
        AUTO_HANDLE = ("int",)
        END_OF_STMT = valf.Const(";")

class Compiler(valf.Visitor):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        
        self._numbers = []

    def visit_int(self, node):
        self._numbers.append(node.value)

    def compile(self, tree):
        self._numbers = []
        self.visit(tree)
        return sum(self._numbers)

if __name__ == '__main__':    
    parser = valf.Parser.from_grammar(Grammar)
    compiler = Compiler()
    
    code = "1;2;3;4;5;6"
    tree = parser.parse(code)
    print(compiler.compile(code))