'use strict';
var util = require('util');
var Action = require('../action');
var c = require('../const');
var ActionAppend = module.exports = function ActionAppend(options) {
options = options || {};
if (this.nargs <= 0) {
throw new Error('nargs for append actions must be > 0; if arg ' +
'strings are not supplying the value to append, ' +
'the append const action may be more appropriate');
}
if (!!this.constant && this.nargs !== c.OPTIONAL) {
throw new Error('nargs must be OPTIONAL to supply const');
}
Action.call(this, options);
};
util.inherits(ActionAppend, Action);
ActionAppend.prototype.call = function (parser, namespace, values) {
var items = (namespace[this.dest] || []).slice();
items.push(values);
namespace.set(this.dest, items);
};