Verified Commit 53896eaf authored by Vladimír Štill's avatar Vladimír Štill
Browse files

CFL: Add a parser test

parent ca2c891e

grammars_cfg.py

+1 −1
Original line number Original line Diff line number Diff line
@@ -160,7 +160,7 @@ class CFG: 




    def _check(self) -> None:

    def _check(self) -> None:

        assert self.init in self.nonterminals,\

        assert self.init in self.nonterminals,\

            "Initial nonterminal {self.init.name} must be in nonterminals"

            f"Initial nonterminal {self.init.name} must be in nonterminals"

        for nterm, prod in self.productions():

        for nterm, prod in self.productions():

            assert nterm in self.nonterminals,\

            assert nterm in self.nonterminals,\

                f"A rule for {nterm.name} exists, "\

                f"A rule for {nterm.name} exists, "\

test_cfl_cfg.py

+19 −6
Original line number Original line Diff line number Diff line 
from common import Nonterminal, Terminal, Eps

from common import Nonterminal, Terminal, Eps

from parser import Parser

import cfl

import cfl

from copy import deepcopy

from copy import deepcopy





S = Nonterminal("S")

S, A, B, C = tuple(Nonterminal(x) for x in "SABC")

A = Nonterminal("A")

a, b, c = tuple(Terminal(x) for x in "abc")

B = Nonterminal("B")

C = Nonterminal("C")

a = Terminal("a")

b = Terminal("b")





Rules = cfl.CFG.Rules

Rules = cfl.CFG.Rules
@@ -133,3 +130,19 @@ def test_equal(): 
    assert not r

    assert not r

    print(r.__dict__)

    print(r.__dict__)







def test_parser():

    parser = Parser()

    pg0 = parser.str_to_cfg("S -> aA | ε | aBC | <foo>C; "

                            "A -> a; "

                            "B -> b; "

                            "C -> c\n"

                            "<foo> -> aaa")

    assert pg0.terminals == {a, b, c}

    assert pg0.nonterminals == {S, A, B, C, Nonterminal("<foo>")}

    assert pg0.generates("")

    assert pg0.generates("aa")

    assert pg0.generates("abc")

    assert pg0.generates("aaac")

    assert pg0.is_epsilon_normal_form()