work.suroh.tk/node_modules/string-width/index.js

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2019-12-02 12:22:45 +00:00
'use strict';
var stripAnsi = require('strip-ansi');
var codePointAt = require('code-point-at');
var isFullwidthCodePoint = require('is-fullwidth-code-point');
// https://github.com/nodejs/io.js/blob/cff7300a578be1b10001f2d967aaedc88aee6402/lib/readline.js#L1345
module.exports = function (str) {
if (typeof str !== 'string' || str.length === 0) {
return 0;
}
var width = 0;
str = stripAnsi(str);
for (var i = 0; i < str.length; i++) {
var code = codePointAt(str, i);
// ignore control characters
if (code <= 0x1f || (code >= 0x7f && code <= 0x9f)) {
continue;
}
// surrogates
if (code >= 0x10000) {
i++;
}
if (isFullwidthCodePoint(code)) {
width += 2;
} else {
width++;
}
}
return width;
};