【Avalon源码】iterator

时间:2024-09-05 12:07:20
function iterator(vars, body, ret) {
var fun = 'for(var ' + vars + 'i=0,n = this.length; i < n; i++){' +
body.replace('_', '((i in this) && fn.call(scope,this[i],i,this))') +
'}' + ret
console.log(fun)
return Function('fn,scope', fun)
} Array.prototype.forEach = iterator('', '_', '')
Array.prototype.filter = iterator('r=[],j=0,', 'if(_)r[j++]=this[i]', 'return r')
Array.prototype.map = iterator('r=[],', 'r[i]=_', 'return r')
Array.prototype.some = iterator('', 'if(_)return true', 'return false')
Array.prototype.every = iterator('', 'if(!_)return false', 'return true') var arr = [1,2,3]
arr.forEach(function(value) {
console.log(value)
})