pyparsing.py 文件源码

def locatedExpr(expr):
    """
    Helper to decorate a returned token with its starting and ending locations in the input string.
    This helper adds the following results names:
     - locn_start = location where matched expression begins
     - locn_end = location where matched expression ends
     - value = the actual parsed results

    Be careful if the input text contains C{<TAB>} characters, you may want to call
    C{L{ParserElement.parseWithTabs}}

    Example::
        wd = Word(alphas)
        for match in locatedExpr(wd).searchString("ljsdf123lksdjjf123lkkjj1222"):
            print(match)
    prints::
        [[0, 'ljsdf', 5]]
        [[8, 'lksdjjf', 15]]
        [[18, 'lkkjj', 23]]
    """
    locator = Empty().setParseAction(lambda s,l,t: l)
    return Group(locator("locn_start") + expr("value") + locator.copy().leaveWhitespace()("locn_end"))


# convenience constants for positional expressions