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Extend the semantics of parentheses #5

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6a6462e
Extend the semantics of parentheses
Super3001 Oct 11, 2024
e978217
Add test cases for nested parentheses
Super3001 Oct 11, 2024
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73 changes: 43 additions & 30 deletions nfa/construction.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -21,18 +21,17 @@ def pattern(pattern_string):
lexer = Lexer(pattern_string)
lexer.advance()
nfa_pair = NfaPair()
group(nfa_pair)
expr(nfa_pair)
# log_nfa(nfa_pair.start_node)

return nfa_pair.start_node


"""
group ::= ("(" expr ")")*
expr ::= factor_conn ("|" factor_conn)*
factor_conn ::= factor | factor factor*
factor ::= (term | term ("*" | "+" | "?"))*
term ::= char | "[" char "-" char "]" | .
term ::= char | "[" char "-" char "]" | . | "(" expr ")"
"""


Expand All @@ -44,6 +43,8 @@ def term(pair_out):
nfa_dot_char(pair_out)
elif lexer.match(Token.CCL_START):
nfa_set_nega_char(pair_out)
elif lexer.match(Token.OPEN_PAREN):
nfa_paren_around(pair_out)


# 匹配单个字符
Expand Down Expand Up @@ -147,7 +148,6 @@ def factor_conn(pair_out):

def is_conn(token):
nc = [
Token.OPEN_PAREN,
Token.CLOSE_PAREN,
Token.AT_EOL,
Token.EOS,
Expand Down Expand Up @@ -226,6 +226,19 @@ def nfa_option_closure(pair_out):
return True


# ()
def nfa_paren_around(pair_out):
if not lexer.match(Token.OPEN_PAREN):
return False

lexer.advance()
expr(pair_out)
if not lexer.match(Token.CLOSE_PAREN):
return False
lexer.advance()
return True


def expr(pair_out):
factor_conn(pair_out)
pair = NfaPair()
Expand All @@ -246,32 +259,32 @@ def expr(pair_out):
return True


def group(pair_out):
if lexer.match(Token.OPEN_PAREN):
lexer.advance()
expr(pair_out)
if lexer.match(Token.CLOSE_PAREN):
lexer.advance()
elif lexer.match(Token.EOS):
return False
else:
expr(pair_out)

while True:
pair = NfaPair()
if lexer.match(Token.OPEN_PAREN):
lexer.advance()
expr(pair)
pair_out.end_node.next_1 = pair.start_node
pair_out.end_node = pair.end_node
if lexer.match(Token.CLOSE_PAREN):
lexer.advance()
elif lexer.match(Token.EOS):
return False
else:
expr(pair)
pair_out.end_node.next_1 = pair.start_node
pair_out.end_node = pair.end_node
# def group(pair_out):
# if lexer.match(Token.OPEN_PAREN):
# lexer.advance()
# expr(pair_out)
# if lexer.match(Token.CLOSE_PAREN):
# lexer.advance()
# elif lexer.match(Token.EOS):
# return False
# else:
# expr(pair_out)

# while True:
# pair = NfaPair()
# if lexer.match(Token.OPEN_PAREN):
# lexer.advance()
# expr(pair)
# pair_out.end_node.next_1 = pair.start_node
# pair_out.end_node = pair.end_node
# if lexer.match(Token.CLOSE_PAREN):
# lexer.advance()
# elif lexer.match(Token.EOS):
# return False
# else:
# expr(pair)
# pair_out.end_node.next_1 = pair.start_node
# pair_out.end_node = pair.end_node



7 changes: 7 additions & 0 deletions test/test.py
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,13 @@ def __init__(self, str, pattern, result):
testLists.append(RegexMaterial("abbbbb", "[^c]+", True))
testLists.append(RegexMaterial("ccccc", "[^c]+", False))
testLists.append(RegexMaterial("123", "[1-3]+", True))
testLists.append(RegexMaterial("ad", "a(bc)*d", True))
testLists.append(RegexMaterial("abcd", "a(bc)*d", True))
testLists.append(RegexMaterial("abcbcd", "a(bc)*d", True))
testLists.append(RegexMaterial("abcdef", "a(b(cd)*e)?f", True))
testLists.append(RegexMaterial("abef", "a(b(cd)*e)?f", True))
testLists.append(RegexMaterial("af", "a(b(cd)*e)?f", True))
testLists.append(RegexMaterial("abf", "a(b(cd)*e)?f", False))

class TestRegex(unittest.TestCase):
def test(self):
Expand Down