textparser_class_based_grammar_definition_quickstart.py

1import textparser
2from textparser import SequenceOf
3from textparser import Choice
4from textparser import Repeat
5
6class HelloParser(textparser.Parser):
7    def token_specs(self):
8        return [
9            ('SKIP',          r'[ \r\n\t]+'),
10            ('WORD',          r'[a-zA-Z]+'),
11            ('COMMA',         r','),
12            ('EXCLAMATION',   r'!'),
13            ('OTHER',         r'.'),
14        ]
15
16    def grammar(self):
17        return SequenceOf(
18            'WORD',
19            'COMMA',
20            'WORD',
21            'EXCLAMATION'
22        )
23
24parser = HelloParser()
25tree = parser.parse('Hello, World!')
26
27print(tree)