Awk in Javascript?

awk.js

/*
 * map predicate to code...
 *   /regex/ --> function (groups, next)
 *                          ^       ^ function to call if we should 
 *                          |       \---skip remaining predicates for this line
 *                          \- e.g.  groups[1] is first regex group, etc
 */

function line(predicate, codeblock) {
  return ({ predicate: predicate, codeblock: codeblock });
}

function awk(predlist, filelist) {
  for (fileno = 0; fileno < filelist; fileno++) {
    var lines = /* insert magic to read file
                 * line-by-line, probably using node-lazy */
    lines.foreach(function (line) {
      var skip = false;
      for (predno = 0; predno < predlist.length; predno++) {
        var p = predlist[predno];
        if (typeof (p.predicate) == 'regex') {
          var m = line.match(p.predicate);
          if (m) {
            p.codeblock(m, function () { skip = true; });
          }
        } /* XXX handle more types of predicates here?
           * e.g. "function(line) --> boolean" predicate?
           */
        if (skip)
          break;
      }
    });
  }
}

example.js

awk([
  line(/(.*): *(.*)/, function(g, next) {
    if (g[1] === 'interface')
      next(); /* skip lines beginning with "interface:" */
  }),
  line(/.*/, function(g, next) {
    console.log('line did not begin with interface: ... ' + g[0]);
  })
], ['/tmp/input.txt']);