tatsu calc example bug?

calc.py

# -*- coding: utf-8 -*-
from __future__ import absolute_import, division, print_function, unicode_literals

import json
from codecs import open
from pprint import pprint

import tatsu
from tatsu.ast import AST
from tatsu.walkers import NodeWalker

from codegen import PostfixCodeGenerator


def simple_parse():
    grammar = open('grammars/calc_cut.ebnf').read()

    parser = tatsu.compile(grammar)
    #ast = parser.parse('3 + 5 * ( 10 - 20 )', trace=False, colorize=True)
    ast = parser.parse('1 * 2 + 3 - 4', trace=False, colorize=True)

    print()
    print('# SIMPLE PARSE')
    print('# AST')
    pprint(ast, width=20, indent=4)
    print()

    print('# JSON')
    print(json.dumps(ast, indent=4))
    print()


def annotated_parse():
    grammar = open('grammars/calc_annotated.ebnf').read()

    parser = tatsu.compile(grammar)
    #ast = parser.parse('3 + 5 * ( 10 - 20 )')
    ast = parser.parse('1 * 2 + 3 - 4')

    print()
    print('# ANNOTATED AST')
    pprint(ast, width=20, indent=4)
    print()


class CalcBasicSemantics(object):
    def number(self, ast):
        return int(ast)

    def term(self, ast):
        if not isinstance(ast, AST):
            return ast
        elif ast.op == '*':
            return ast.left * ast.right
        elif ast.op == '/':
            return ast.left / ast.right
        else:
            raise Exception('Unknown operator', ast.op)

    def expression(self, ast):
        if not isinstance(ast, AST):
            return ast
        elif ast.op == '+':
            return ast.left + ast.right
        elif ast.op == '-':
            return ast.left - ast.right
        else:
            raise Exception('Unknown operator', ast.op)


def parse_with_basic_semantics():
    grammar = open('grammars/calc_annotated.ebnf').read()

    parser = tatsu.compile(grammar)
    result = parser.parse(
        #'3 + 5 * ( 10 - 20 )',
        '1 * 2 + 3 - 4',
        semantics=CalcBasicSemantics()
    )

    print()
    print('# BASIC SEMANTICS RESULT')
    #assert result == -47
    assert result == 1
    print(result)
    print()


class CalcSemantics(object):
    def number(self, ast):
        return int(ast)

    def addition(self, ast):
        return ast.left + ast.right

    def subtraction(self, ast):
        return ast.left - ast.right

    def multiplication(self, ast):
        return ast.left * ast.right

    def division(self, ast):
        return ast.left / ast.right


def parse_factored():
    grammar = open('grammars/calc_factored.ebnf').read()

    parser = tatsu.compile(grammar)
    ast = parser.parse(
        #'3 + 5 * ( 10 - 20 )',
        '1 * 2 + 3 - 4',
        semantics=CalcSemantics()
    )

    print()
    print('# FACTORED SEMANTICS RESULT')
    pprint(ast, width=20, indent=4)
    print()


def parse_to_model():
    grammar = open('grammars/calc_model.ebnf').read()

    parser = tatsu.compile(grammar, asmodel=True)
    #model = parser.parse('3 + 5 * ( 10 - 20 )')
    model = parser.parse('1 * 2 + 3 - 4')

    print()
    print('# MODEL TYPE IS:', type(model).__name__)
    print(json.dumps(model.asjson(), indent=4))
    print()


class CalcWalker(NodeWalker):
    def walk_object(self, node):
        return node

    def walk__add(self, node):
        return self.walk(node.left) + self.walk(node.right)

    def walk__subtract(self, node):
        return self.walk(node.left) - self.walk(node.right)

    def walk__multiply(self, node):
        return self.walk(node.left) * self.walk(node.right)

    def walk__divide(self, node):
        return self.walk(node.left) / self.walk(node.right)


def parse_and_walk_model():
    grammar = open('grammars/calc_model.ebnf').read()

    parser = tatsu.compile(grammar, asmodel=True)
    #model = parser.parse('3 + 5 * ( 10 - 20 )')
    model = parser.parse('1 * 2 + 3 - 4')

    print()
    print('# WALKER RESULT')
    result = CalcWalker().walk(model)
    assert result == -47
    print(result)
    print()


def parse_and_translate():
    grammar = open('grammars/calc_model.ebnf').read()

    parser = tatsu.compile(grammar, asmodel=True)
    #model = parser.parse('3 + 5 * ( 10 - 20 )')
    model = parser.parse('1 * 2 + 3 - 4')

    postfix = PostfixCodeGenerator().render(model)

    print()
    print('# TRANSLATED TO POSTFIX')
    print(postfix)


def main():
    simple_parse()
    annotated_parse()
    parse_with_basic_semantics()
    parse_factored()
    parse_to_model()
    parse_and_walk_model()
    parse_and_translate()


if __name__ == '__main__':
    main()

err.log

Traceback (most recent call last):
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 203, in parse
    result = rule()
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 693, in parse
    result = self._parse_rhs(ctx, self.exp)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 700, in _parse_rhs
    result = ctx._call(ruleinfo)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 509, in _call
    result = self._recursive_call(ruleinfo)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 540, in _recursive_call
    result = self._invoke_rule(ruleinfo, key)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 573, in _invoke_rule
    ruleinfo.impl(self)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 348, in parse
    ctx.last_node = [s.parse(ctx) for s in self.sequence]
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 348, in <listcomp>
    ctx.last_node = [s.parse(ctx) for s in self.sequence]
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 203, in parse
    ctx._check_eof()
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 642, in _check_eof
    self._error('Expecting end of text', exclass=FailedExpectingEndOfText)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 435, in _error
    raise self._make_exception(item, exclass=exclass)
tatsu.exceptions.FailedExpectingEndOfText: (1:11) Expecting end of text :
1 * 2 + 3 - 4
          ^
start

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "calc.py", line 192, in <module>
    main()
  File "calc.py", line 185, in main
    parse_factored()
  File "calc.py", line 113, in parse_factored
    semantics=CalcSemantics()
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 945, in parse
    **kwargs
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 211, in parse
    raise self._furthest_exception
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 672, in _option
    yield
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 394, in parse
    ctx.last_node = o.parse(ctx)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 649, in parse
    return rule()
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 693, in parse
    result = self._parse_rhs(ctx, self.exp)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 700, in _parse_rhs
    result = ctx._call(ruleinfo)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 509, in _call
    result = self._recursive_call(ruleinfo)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 540, in _recursive_call
    result = self._invoke_rule(ruleinfo, key)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 573, in _invoke_rule
    ruleinfo.impl(self)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 348, in parse
    ctx.last_node = [s.parse(ctx) for s in self.sequence]
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 348, in <listcomp>
    ctx.last_node = [s.parse(ctx) for s in self.sequence]
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 586, in parse
    value = self.exp.parse(ctx)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/grammars.py", line 266, in parse
    return ctx._token(self.token)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 610, in _token
    self._error(token, exclass=FailedToken)
  File "/home/lain/.local/lib/python3.6/site-packages/tatsu/contexts.py", line 435, in _error
    raise self._make_exception(item, exclass=exclass)
tatsu.exceptions.FailedToken: (1:11) expecting '*' :
1 * 2 + 3 - 4
          ^
multiplication
term
addition
expression
start