in build-support/cpplint.py [0:0]
def FindStartOfExpressionInLine(line, endpos, stack):
"""Find position at the matching start of current expression.
This is almost the reverse of FindEndOfExpressionInLine, but note
that the input position and returned position differs by 1.
Args:
line: a CleansedLines line.
endpos: start searching at this position.
stack: nesting stack at endpos.
Returns:
On finding matching start: (index at matching start, None)
On finding an unclosed expression: (-1, None)
Otherwise: (-1, new stack at beginning of this line)
"""
i = endpos
while i >= 0:
char = line[i]
if char in ')]}':
# Found end of expression, push to expression stack
stack.append(char)
elif char == '>':
# Found potential end of template argument list.
#
# Ignore it if it's a "->" or ">=" or "operator>"
if (i > 0 and
(line[i - 1] == '-' or
Match(r'\s>=\s', line[i - 1:]) or
Search(r'\boperator\s*$', line[0:i]))):
i -= 1
else:
stack.append('>')
elif char == '<':
# Found potential start of template argument list
if i > 0 and line[i - 1] == '<':
# Left shift operator
i -= 1
else:
# If there is a matching '>', we can pop the expression stack.
# Otherwise, ignore this '<' since it must be an operator.
if stack and stack[-1] == '>':
stack.pop()
if not stack:
return (i, None)
elif char in '([{':
# Found start of expression.
#
# If there are any unmatched '>' on the stack, they must be
# operators. Remove those.
while stack and stack[-1] == '>':
stack.pop()
if not stack:
return (-1, None)
if ((char == '(' and stack[-1] == ')') or
(char == '[' and stack[-1] == ']') or
(char == '{' and stack[-1] == '}')):
stack.pop()
if not stack:
return (i, None)
else:
# Mismatched parentheses
return (-1, None)
elif char == ';':
# Found something that look like end of statements. If we are currently
# expecting a '<', the matching '>' must have been an operator, since
# template argument list should not contain statements.
while stack and stack[-1] == '>':
stack.pop()
if not stack:
return (-1, None)
i -= 1
return (-1, stack)