def conditionAsParseAction(fn, message=None, fatal=False):
msg = coalesce(message, "failed user-defined condition")
exc_type = ParseFatalException if fatal else ParseException
fn = wrap_parse_action(fn)
@wraps(fn)
def pa(t, l, s):
if not bool(fn(t, l, s)[0]):
raise exc_type(s, l, msg)
return t
return pa
def addCondition(self,
*fns,
message=None,
callDuringTry=False,
fatal=False):
"""
Add a boolean predicate function to expression's list of parse actions. See
`setParseAction` for function call signatures. Unlike ``setParseAction``,
functions passed to ``addCondition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise ParseException
"""
def make_cond(fn):
def cond(token, index, string):
result = fn(token, index, string)
if not bool(result.tokens[0]):
if fatal:
Log.error(
"fatal error",
casue=ParseException(token.type,
index,
string,
msg=message),
)
raise ParseException(token.type,
index,
string,
msg=message)
return token
return cond
output = self.copy()
for fn in fns:
output.parseAction.append(make_cond(wrap_parse_action(fn)))
output.set_config(
callDuringTry=self.parser_config.callDuringTry or callDuringTry)
return output
def __init__(self, methodCall):
self.callable = wrap_parse_action(methodCall)
self.called = False