Show HN: Nevod is easier and faster than RegExp

The Perl 6 grammar engine does full parsing, and gives you the parse tree that matches the structure of the rules.

One of the best and most powerful alternatives to RegEx I've ever seen is the PARSE function used in the Rebol and Red programming languages.

    page: read http://hq.rebol.net
    parse page [thru  copy title to ]
    print title
    The REBOL Developer Network

regex is quite powerful and free anyway, I would consider some of these opensource tools to tackle its complexity:

http://regex.inginf.units.it/ http://buildregex.com/ https://regexr.com/

The claims seem dubious to me as well. What exactly does faster mean here? Since a speedup of two orders of magnitude is mentioned I'm assuming it refers to matching speed.

Is it faster than PCRE? Is it faster than some other engine or is the claim that it's faster than any available RegEx engine? I had a quick look at the reference and this looks like it will accept context-free languages (since recursion is allowed). I strongly doubt that a CFG parser is magically faster than any RegEx engine.

> It is hundreds of times faster than the well-known regular expressions, and the speed doesn’t degrade linearly when you add patterns.

The author seems to believe that matching time for RegExes is linear in the time of the pattern? Once compiled to a DFA, the pattern only has negligible influence on the matching time.

EDIT: I've been trying to figure out what kind of parser this generates. It might be a LR(k) parser? It breaks on the following (admittedly contrived) example:

  #S = E + End;
  E = {E + "+" + E, E + "*" + E, T};
  T = {[1+]Alpha, N + "()"};
  N = {P, Q};
  P = {"a" + P, "ab"};
  Q = [1+]"a";

with an input of "aaaaaaab()+beta*c"

I like the compactness and syntax of Red a lot.

Pharo's Petit Parser is a framework for building parsers that is also pretty nifty [1].

[1] https://github.com/moosetechnology/PetitParser