test_sequence_params.py 2.01 KB
# -*- coding: utf-8 -*-
#######################################################################
# Name: test_sequence_params
# Purpose: Test Sequence expression parameters.
# Author: Igor R. Dejanović <igor DOT dejanovic AT gmail DOT com>
# Copyright: (c) 2014 Igor R. Dejanović <igor DOT dejanovic AT gmail DOT com>
# License: MIT License
#######################################################################

from __future__ import unicode_literals
import pytest
from arpeggio import ParserPython, NoMatch, Sequence
from arpeggio import RegExMatch as _


def test_skipws():
    """
    skipws may be defined per Sequence.
    """

    def grammar():     return Sequence("one", "two", "three"), "four"

    parser = ParserPython(grammar)

    # By default, skipws is True and whitespaces will be skipped.
    parser.parse("one two   three  four")


    def grammar():     return Sequence("one", "two", "three",
                                       skipws=False), "four"

    parser = ParserPython(grammar)

    # If we disable skipws for sequence only then whitespace
    # skipping should not be done inside sequence.
    with pytest.raises(NoMatch):
        parser.parse("one two   three  four")

    # But it will be done outside of it
    parser.parse("onetwothree  four")


def test_ws():
    """
    ws can be changed per Sequence.
    """

    def grammar():     return Sequence("one", "two", "three"), "four"

    parser = ParserPython(grammar)

    # By default, ws consists of space, tab and newline
    # So this should parse.
    parser.parse("""one
            two   three  four""")


    def grammar():     return Sequence("one", "two", "three",
                                       ws=' '), "four"

    parser = ParserPython(grammar)

    # If we change ws per sequence and set it to space only
    # given input will raise exception
    with pytest.raises(NoMatch):
        parser.parse("""one
                two   three  four""")

    # But ws will be default outside of sequence
    parser.parse("""one two  three
        four""")