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Parse unary expressions left to right and fail if extra tokens are found

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This fixes the case where there is garbage after a valid unary operator.
This commit is contained in:
Salvo 'LtWorf' Tomaselli 2020-08-12 20:16:40 +02:00
parent d5a8975d9b
commit 9d1f25d65d
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GPG Key ID: B3A7CF0C801886CF
1 changed files with 4 additions and 1 deletions
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relational/parser.py
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@ -311,11 +311,14 @@ def parse_tokens(expression: List[Union[list, str]]) -> Node:
f'Expected right operand for {expression[i]!r}')
return Binary(expression[i], parse_tokens(expression[:i]), parse_tokens(expression[i + 1:])) # type: ignore
'''Searches for unary operators, parsing from right to left'''
for i in range(len(expression) - 1, -1, -1):
for i in range(len(expression)):
if expression[i] in u_operators: # Unary operator
if len(expression) <= i + 2:
raise ParserException(
f'Expected more tokens in {expression[i]!r}')
elif len(expression) > i + 3:
raise ParserException(
f'Too many tokens in {expression[i]!r}')
return Unary(
expression[i], # type: ignore