def test_isolatedBracedEnd(self):
my_parser = pushdown.Lark(
r"""
start: braced_free_input_string " {"
constant_usage: CONSTANT_USAGE_
text_chunk: TEXT_CHUNK_
CONSTANT_USAGE_: /\$[^\n\$\:]+\:/
TEXT_CHUNK_: /(\\{|\\}|\\\$|[^\n{}\$])+/
braced_free_input_string: ( constant_usage | text_chunk )* ( braced_constant_usage_end | braced_text_chunk_end )
braced_constant_usage_end: BRACED_CONSTANT_USAGE_END_
braced_text_chunk_end: BRACED_TEXT_CHUNK_END_
BRACED_CONSTANT_USAGE_END_: /(?:\$[^\n\$\:]+\:)(?=(?: \u007b))/
BRACED_TEXT_CHUNK_END_: /(\\{|\\}|\\\$|[^\n{}\$])+(?=(?: \u007b))/
""",
start='start', parser='lalr', lexer='contextual' )
tree = my_parser.parse( r"true$constant:\$|false {" )
self.assertTextEqual(
r"""
+ start
+ braced_free_input_string
+ text_chunk [@1,0:3='true'<TEXT_CHUNK_>,1:1]
+ constant_usage [@2,4:13='$constant:'<CONSTANT_USAGE_>,1:5]
+ braced_text_chunk_end [@3,14:21='\\$|false'<BRACED_TEXT_CHUNK_END_>,1:15]
""", tree.pretty(debug=True) )
def _getParser(self, log_level):
## The relative path the the pushdown grammar parser file from the current file
grammar_file_path = get_relative_path( "grammars_grammar.pushdown", __file__ )
## The parser used to build the Abstract Syntax Tree and parse the input text
with open( grammar_file_path, "r", encoding='utf-8' ) as file:
my_parser = pushdown.Lark( file.read(), start='language_syntax', parser='lalr', lexer='contextual', debug=log_level)
return my_parser
def test_isolatedConstantUsage(self):
my_parser = pushdown.Lark(
r"""
free_input_string: ( constant_usage | text_chunk )* ( constant_usage_end | text_chunk_end )
constant_usage: CONSTANT_USAGE_
text_chunk: TEXT_CHUNK_
constant_usage_end: CONSTANT_USAGE_END_
text_chunk_end: TEXT_CHUNK_END_
CONSTANT_USAGE_: /\$[^\n\$\:]+\:/
TEXT_CHUNK_: /(\\{|\\}|\\\$|[^\n{}\$])+/
CONSTANT_USAGE_END_: /(?:\$[^\n\$\:]+\:)(?=(?:\n|$))/
TEXT_CHUNK_END_: /(\\{|\\}|\\\$|[^\n{}\$])+(?=(?:\n|$))/
""",
start='free_input_string', parser='lalr', lexer='contextual' )
tree = my_parser.parse( r"true$constant:\$|false" )
self.assertTextEqual(
r"""
+ free_input_string
+ text_chunk [@1,0:3='true'<TEXT_CHUNK_>,1:1]
+ constant_usage [@2,4:13='$constant:'<CONSTANT_USAGE_>,1:5]
+ text_chunk_end [@3,14:21='\\$|false'<TEXT_CHUNK_END_>,1:15]
""", tree.pretty(debug=True) )
#! /usr/bin/env python
# -*- coding: utf-8 -*-
import pushdown
_parser = pushdown.Lark(r"""
start: terminal_name
terminal_name: TOKEN_NAME
TOKEN_NAME: /ab/
""",
start='start',
parser='lalr',
lexer='contextual')
tree = _parser.parse("ab")
print(tree)
print(tree.pretty())
#! /usr/bin/env python
# -*- coding: utf-8 -*-
import pushdown
_parser = pushdown.Lark(r"""
start: a b
a: "A" "B"
b: "AB"
""",
start='start',
parser='lalr',
lexer='contextual')
tree = _parser.parse("AB\nBABAB")
print(tree.pretty())