45 lines
1.5 KiB
Python
45 lines
1.5 KiB
Python
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from .types import SupportSign, SentenceConjunction, SentenceVariable, Negation
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def is_formula_correct(formula):
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""" Run all test on formula """
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if not formula:
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return True
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else:
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formula = formula.replace(' ', '')
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return all([check_order(formula), check_parenthesis(formula)])
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def check_parenthesis(formula: str) -> bool:
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""" Check if all brackets are opened and closed correctly """
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stack_of_expected_sings = []
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for sign in formula:
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if sign in SupportSign.symbols_open:
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inverse_of_sign = SupportSign.get_closed_symbol(sign)
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stack_of_expected_sings.append(inverse_of_sign)
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elif sign in SupportSign.symbols_close:
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if stack_of_expected_sings.pop() != sign:
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return False
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return not stack_of_expected_sings
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def check_order(formula: str) -> bool:
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""" Check if all sings have correct preceding and next sign """
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expected_sign = []
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for sign in formula:
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if sign in SupportSign.symbols:
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continue
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if expected_sign and sign not in expected_sign:
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return False
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if sign in Negation.symbols:
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expected_sign = SentenceVariable.symbols
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elif sign in SentenceConjunction.symbols:
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expected_sign = Negation.symbols + SentenceVariable.symbols
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elif sign in SentenceVariable.symbols:
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expected_sign = SentenceConjunction.symbols
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return any(symbol in expected_sign for symbol in SentenceVariable.symbols)
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