Created
March 29, 2012 02:49
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Maybe monad? in JavaScript
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| // usage: | |
| // var target = {hoge: {fuga: 'muga'}}; | |
| // maybe(target, 'hoge', 'fuga') //=> 'muga' | |
| // maybe(target, 'moge', 'fuga') //=> undefined | |
| // maybe(target, 'hoge', 'fuga', ['match', /^m/]) //=> ['m'] | |
| // maybe(target, 'moge', 'fuga', ['match', /^m/]) //=> undefined | |
| function maybe() { | |
| var self = arguments[0]; | |
| var methodChain = [].slice.apply(arguments, [1]); | |
| var len = methodChain.length; | |
| for (var i=0; i < len; ++i) { | |
| var ops = methodChain[i]; | |
| if (typeof(ops) === 'string') | |
| ops = [ops]; | |
| var message = ops[0]; | |
| var args = ops.slice(1); | |
| if (self === undefined || self === null) { | |
| self = undefined; | |
| } else { | |
| if (typeof(self[message]) === 'function') { | |
| self = self[message].apply(self, args); | |
| } else { | |
| self = self[message]; | |
| } | |
| } | |
| } | |
| return self; | |
| } |
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