index.js
function val (params, spec, errs) {
  for (var key in params) {
    if (key in spec && isFunction(spec[key].val) && !spec[key].val(params[key])) valError(key, errs)
  }
}
function val (params, spec, errs) {
  for (var key in params) {
    if (key in spec && isFunction(spec[key].val) && !spec[key].val(params[key])) valError(key, errs)
  }
}
function val ( params , spec , errs ) { for ( var key in params ) { if ( key in spec && isFunction ( spec [ key ] . val ) && ! spec [ key ] . val ( params [ key ] ) ) valError ( key , errs ) } }
Ensure that validation predicates pass.

@param {Object} params
Parameters value object.

@param {String} spec
Parameters definition object.

@param {Array} errs
Errors list.
Ensure that validation predicates pass .