为什么我就是能这样娴熟地加上空格呢？

text-autospace.js

// https://zizhengwu.github.io/daft-auto-spacing/
var unicode = [];

unicode['latin'] = ['[A-Za-z0-9\u00C0-\u00FF\u0100-\u017F\u0180-\u024F\u1E00-\u1EFF]'];
unicode['punc'] = ['[@&=_\,\.\?\!\$\%\^\*\-\+\/]', '[\(\\[\'"<‘“]', '[\)\\]\'">”’]'];
unicode['hanzi'] = ['[\u4E00-\u9FFF]', '[\u3400-\u4DB5\u9FA6-\u9FBB\uFA70-\uFAD9\u9FBC-\u9FC3\u3007\u3040-\u309E\u30A1-\u30FA\u30FD\u30FE\uFA0E-\uFA0F\uFA11\uFA13-\uFA14\uFA1F\uFA21\uFA23-\uFA24\uFA27-\uFA29]', '[\uD840-\uD868][\uDC00-\uDFFF]|\uD869[\uDC00-\uDEDF]', '\uD86D[\uDC00-\uDF3F]|[\uD86A-\uD86C][\uDC00-\uDFFF]|\uD869[\uDF00-\uDFFF]', '\uD86D[\uDF40-\uDFFF]|\uD86E[\uDC00-\uDC1F]', '[\u31C0-\u31E3]'];
unicode['biaodian'] = ['[·・︰、，。：；？！—ー⋯…．·／]', '[「『（〔【《〈“‘]', '[」』）〕】》〉’”]'];
unicode['zhuyin'] = [];
unicode['zhuyin'][0] = '[\u3105-\u312D\u31A0-\u31BA]';
unicode['zhuyin']['shengmu'] = '[\u3105-\u3119\u312A-\u312C\u31A0-\u31A3]';
unicode['zhuyin']['jieyin'] = '[\u3127-\u3129]';
unicode['zhuyin']['yunmu'] = '[\u311A-\u3126\u312D\u31A4-\u31B3\u31B8-\u31BA]';
unicode['zhuyin']['yunjiao'] = '[\u31B4-\u31B7]';
unicode['zhuyin']['diao'] = '[\u02D9\u02CA\u02C5\u02C7\u02CB\u02EA\u02EB]';

var unicode_set = function(set) {
    var join = (set.match(/[hanzi|latin]/)) ? true : false;
    var result = (join) ? unicode[set].join('|') : unicode[set];
    return result;
};

var text_replace = function() {
    var hanzi = unicode_set('hanzi');
    var latin = unicode_set('latin') + '|' + unicode['punc'][0];
    var punc = unicode['punc'];
    var patterns = ['/(' + hanzi + ')(' + latin + '|' + punc[1] + ')/ig', '/(' + latin + '|' + punc[2] + ')(' + hanzi + ')/ig'];

    var dom1 = document.querySelector(".no-space");
    var dom2 = document.querySelector(".with-space");
    var text = dom1.value;

    patterns.forEach(function(exp) {
        text = text.replace(eval(exp), '$1 $2');
    },
    this);

    dom2.value = text;
};