mirror of https://github.com/jkjoy/sunpeiwen.git
19 lines
561 B
TypeScript
19 lines
561 B
TypeScript
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// https://mathiasbynens.be/notes/javascript-encoding
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// https://github.com/bestiejs/punycode.js - punycode.ucs2.decode
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export default function ucs2length(str: string): number {
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const len = str.length
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let length = 0
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let pos = 0
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let value: number
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while (pos < len) {
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length++
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value = str.charCodeAt(pos++)
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if (value >= 0xd800 && value <= 0xdbff && pos < len) {
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// high surrogate, and there is a next character
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value = str.charCodeAt(pos)
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if ((value & 0xfc00) === 0xdc00) pos++ // low surrogate
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}
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}
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return length
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}
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