rules.py 文件源码

def _build_parser():
    date_literal = pp.Regex(r'(?P<year>\d{4})/(?P<month>\d{2})/(?P<day>\d{2})') \
                     .setParseAction(lambda s,l,t: schema.Date(t.year, t.month, t.day))
    dollars_literal = pp.Regex(r'\$\d+(\.\d{2})') \
                        .setParseAction(lambda s,l,t: schema.Dollars(t[0]))
    string_literal = (pp.QuotedString('"', escChar='\\') | pp.QuotedString("'", escChar='\\')) \
                     .setParseAction(lambda s,l,t: schema.String(t[0]))
    literal = date_literal | dollars_literal | string_literal

    ident = pp.Word(pp.alphas)

    match_op = pp.oneOf(operator_map.keys())
    match = ident + match_op + literal

    assign_op = pp.Literal('=')
    assign = ident + assign_op + literal

    part = (match | assign).setParseAction(lambda s,l,t: [t])
    rule = pp.delimitedList(part) + pp.LineEnd()

    return rule