Java库将正则表达式解析为语法树

Question

I'd like a library that can take the string representation of a regexp and convert that into a syntax tree for easy programmatic manipulation. Something that would transform:

(\\s?)bla[az]

into something like:

PARENTHESIS
  CHAR:SPACE
    WILD
WORD:bla
CHAR:a-z

Answer 1

Looks like what you're looking for is a syntax parser, right?

I would give a look on antlr (http://www.antlr.org/), you can create grammars and it will generate a syntax tree which you can walk, translate etc.

Answer 2

Parboiled looks like a good choice for what you want to make.

It allows easy writing of grammars, way more easily than antlr or javacc.

Sample:

Rule Digit()
{
    return CharRange('0', '9');
}

Rule Integer()
{
    return OneOrMore(Digit());
}

Rule WhiteSpace()
{
    return ZeroOrMore(AnyOf(" \t"));
}

Rule NToMQuantifier()
{
    return Sequence(
        '{',
        WhiteSpace(),
        Integer(),
        Optional(
            WhiteSpace(),
            Integer()
        ),
        '}'
    );
}

Rule OtherQuantifiers()
{
    return Sequence(AnyOf("+?*"), Optional(AnyOf("+?")));
}

Rule Quantifier()
{
    return FirstOf(OtherQuantifiers(), NToMQuantifier());
}