angular 源码中似乎有重复的代码?

[alsodium]

var lowercase = function (string) {
    return isString (string) ? string.toLowerCase () : string;
};

var manualLowercase = function (s) {
    return isString (s) ? s.replace (/[A-Z]/g, function (ch) {
        return String.fromCharCode (ch.charCodeAt (0) | 32);
    }) : s;
};

这两个函数作用是相同的吧,可是为什么要写两个呢?反正都是将大写变小写

[doublleft]

涨姿势

[p2p]

// String#toLowerCase and String#toUpperCase don't produce correct results in browsers with Turkish
// locale, for this reason we need to detect this case and redefine lowercase/uppercase methods
// with correct but slower alternatives.

if ('i' !== 'I'.toLowerCase()) {
lowercase = manualLowercase;
uppercase = manualUppercase;
}

[rannnn]

土耳其语的 i 大写是不是 I
比如'input'.toUpperCase() !== 'INPUT'