wcwidth-o1/dist/index.js

glibc wcwidth/wcswidth for Node.js & TypeScript.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.wcwidth = wcwidth;
exports.wcswidth = wcswidth;
const table_1 = require("./table");
/**
 * Determine number of column positions required for CH.
 *
 * - Accepts a single Unicode character as input.
 *
 * @param char A single Unicode character.
 * @returns Width of the character: 0, 1, 2, or -1 if not printable.
 */
function wcwidth(char) {
    const cp = char.codePointAt(0);
    if (cp === undefined)
        return -1;
    const res = wcwidthTableLookup(cp);
    return res === 0xFF ? -1 : res;
}
/**
 * Determine number of column positions required for first N wide characters
 * (or fewer if S ends before this) in S.
 *
 * - Stops early and returns -1 if any character is non-printable.
 * - If `n` is given, only the first `n` characters are considered.
 *
 * @param str Input string to measure.
 * @param n Optional maximum number of characters to process.
 * @returns Total display width or -1 if any character is unprintable.
 */
function wcswidth(str, n) {
    if (!str)
        return 0;
    const chars = Array.from(str);
    let width = 0;
    for (let i = 0; i < chars.length; i++) {
        if (n !== undefined && i >= n)
            break;
        const w = wcwidth(chars[i]);
        if (w < 0)
            return -1;
        width += w;
    }
    return width;
}
/**
 * Low-level lookup for wcwidth.
 *
 * @param cp Unicode code point (0–0x10FFFF)
 * @returns 0, 1, 2 if valid, else 0xFF
 */
function wcwidthTableLookup(cp) {
    const view = new DataView(table_1.TABLE.buffer, table_1.TABLE.byteOffset, table_1.TABLE.byteLength);
    const shift1 = view.getUint32(0, true);
    const bound = view.getUint32(4, true);
    const index1 = cp >>> shift1;
    if (index1 >= bound)
        return 0xFF;
    const lookup1 = view.getUint32(20 + index1 * 4, true);
    if (!lookup1)
        return 0xFF;
    const shift2 = view.getUint32(8, true);
    const mask2 = view.getUint32(12, true);
    const index2 = (cp >>> shift2) & mask2;
    const lookup2 = view.getUint32(lookup1 + index2 * 4, true);
    if (!lookup2)
        return 0xFF;
    const mask3 = view.getUint32(16, true);
    const index3 = cp & mask3;
    const lookup3 = table_1.TABLE[lookup2 + index3];
    return lookup3;
}
exports.default = wcwidth;
module.exports = wcwidth;
module.exports.default = wcwidth;
module.exports.wcwidth = wcwidth;
module.exports.wcswidth = wcswidth;