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|
import textwrap
from typing import List
from pegen.grammar_parser import GeneratedParser as GrammarParser
from pegen.grammar_visualizer import ASTGrammarPrinter
from pegen.utils import parse_string
def test_simple_rule() -> None:
grammar = """
start: 'a' 'b'
"""
rules = parse_string(grammar, GrammarParser)
printer = ASTGrammarPrinter()
lines: List[str] = []
printer.print_grammar_ast(rules, printer=lines.append)
output = "\n".join(lines)
expected_output = textwrap.dedent(
"""\
└──Rule
└──Rhs
└──Alt
├──NamedItem
│ └──StringLeaf("'a'")
└──NamedItem
└──StringLeaf("'b'")
"""
)
assert output == expected_output
def test_multiple_rules() -> None:
grammar = """
start: a b
a: 'a'
b: 'b'
"""
rules = parse_string(grammar, GrammarParser)
printer = ASTGrammarPrinter()
lines: List[str] = []
printer.print_grammar_ast(rules, printer=lines.append)
output = "\n".join(lines)
expected_output = textwrap.dedent(
"""\
└──Rule
└──Rhs
└──Alt
├──NamedItem
│ └──NameLeaf('a')
└──NamedItem
└──NameLeaf('b')
└──Rule
└──Rhs
└──Alt
└──NamedItem
└──StringLeaf("'a'")
└──Rule
└──Rhs
└──Alt
└──NamedItem
└──StringLeaf("'b'")
"""
)
assert output == expected_output
def test_deep_nested_rule() -> None:
grammar = """
start: 'a' ['b'['c'['d']]]
"""
rules = parse_string(grammar, GrammarParser)
printer = ASTGrammarPrinter()
lines: List[str] = []
printer.print_grammar_ast(rules, printer=lines.append)
output = "\n".join(lines)
print()
print(output)
expected_output = textwrap.dedent(
"""\
└──Rule
└──Rhs
└──Alt
├──NamedItem
│ └──StringLeaf("'a'")
└──NamedItem
└──Opt
└──Rhs
└──Alt
├──NamedItem
│ └──StringLeaf("'b'")
└──NamedItem
└──Opt
└──Rhs
└──Alt
├──NamedItem
│ └──StringLeaf("'c'")
└──NamedItem
└──Opt
└──Rhs
└──Alt
└──NamedItem
└──StringLeaf("'d'")
"""
)
assert output == expected_output
|
