String string(Bool(String) strfun, var ParseState st)
Arguments
strfun: The predicate function, which should return true if the String matchesst: The current parsing state
Usage
Parse a string matching a predicate. The string will be formed from the contiguous set of non-whitespace characters at the start of the String to be parsed (which may be the empty String). An Exception will be thrown if the predicate is not matched.