argParser

by Hans PUFAL

JavaScript

function argParser(args, specs, opts) {
  "use strict"; //========================= argParser ===
  function setArg(arg, spec, val) {
    (Array.isArray(arg) ? arg : [arg]).concat(spec.alias || []).forEach(
      function(argn) {
        if (spec.multi)
          argn in argObj ? argObj[argn].push(val) : (argObj[argn] = [val]);
        else if (argn in argObj && !(spec.typ || 's')[0] == 'b')
          (argObj._errs || (argObj._errs = [])).push('Arg ' + argn + ' previously set to ' +
            argObj[argn]);
        else
          argObj[argn] = val;
      })
  };

  var argObj = {
    _: ''
  };
  (opts = opts || {}).argString && (argObj[opts.argString] = args);
  args = !Array.isArray(args) ? '' + args : args.join(' ');

  for (var arg, val, argn, argspec; arg = args.match(/^\s*(-|--)([a-z_$][\w_$]*)?[\s$]/i);) {
    args = args.slice(arg[0].length);
    val = undefined;
    if (!(argn = arg[2])) break;
    argn = arg[1] == '-' ? argn.split('') : [argn];
    while (argn.length) {
      if (!(argspec = specs[Object.keys(specs).find(
          function(key) {
            var k = key.split(/(?:\s*,\s*)/);
            return k.indexOf(argn[0]) != -1 ||
              specs[key].alias == argn[0] ||
              specs[key].alias && specs[key].alias.find &&
              specs[key].alias.find(function(alias) {
                return alias == argn[0] ? !!(argn[0] = key) : false
              })
          })])) {
        if (!(argspec = opts.defaultSpec || {})) {
          (argObj._errs || (argObj._errs = [])).push('No spec for ' + arg[2]);
          argn.shift();
          continue
        }
      }

      if (argn.length == 1)
        break;

      switch ((argspec.typ || 's')[0]) {
        case 'b':
          val = !(argn[0] in argObj ? argObj[argn[0]] : argspec.dflt);
          break;

        case 'n':
          if (val = argn.join('').match(/^.((0x[\da-f]+)|(0o[0-7]+)|(0b[01]+)|\d+)/i)) {
            argn.splice(1, val[1].length);
            val = +val[1];
     ...