meaw/lib/index.d.cts

Utilities for Unicode East Asian Width

type EastAsianWidth = "N" | "Na" | "W" | "F" | "H" | "A";

declare const version: string;

/**
 * Gets the EAW property of a code point.
 * @param codePoint Code point
 * @return The EAW property of the code point
 * @example
 * import { getEAWOfCodePoint } from "meaw";
 *
 * // 0x3042 is the code point of 'あ' (U+3042)
 * assert(getEAWOfCodePoint(0x3042) === "W");
 */
declare function getEAWOfCodePoint(codePoint: number): EastAsianWidth | undefined;
/**
 * Gets the EAW property of a character.
 * @param str Character string
 * @param pos Character position (in code unit) (default = 0)
 * @return The EAW property of the character
 * @example
 * import { getEAW } from "meaw";
 *
 * // Narrow
 * assert(getEAW("A") === "Na");
 * // Wide
 * assert(getEAW("あ") === "W");
 * assert(getEAW("安") === "W");
 * assert(getEAW("🍣") === "W");
 * // Fullwidth
 * assert(getEAW("Ａ") === "F");
 * // Halfwidth
 * assert(getEAW("ｱ") === "H");
 * // Ambiguous
 * assert(getEAW("∀") === "A");
 * assert(getEAW("→") === "A");
 * assert(getEAW("Ω") === "A");
 * assert(getEAW("Я") === "A");
 * // Neutral
 * assert(getEAW("ℵ") === "N");
 *
 * // character position (in code unit) can be specified
 * assert(getEAW("ℵAあＡｱ∀", 2) === "W");
 */
declare function getEAW(str: string, pos?: number): EastAsianWidth | undefined;

/**
 * Computes the width of a string based on the EAW properties of the characters.
 * By default, characters with property Wide (W) or Fullwidth (F) are treated as wide (= 2)
 * and others are as narrow (= 1).
 * @deprecated
 * @param str Character string
 * @param widths An object that maps EAW properties to character widths
 * @return The computed width
 * @example
 * import { computeWidth } from "meaw";
 *
 * assert(computeWidth("Aあ🍣Ω") === 6);
 * // character width for each EAW property can be customized
 * assert(computeWidth("Aあ🍣Ω", { "A": 2 }) === 7);
 */
declare function computeWidth(str: string, widths?: Readonly<Partial<Record<EastAsianWidth, number>>>): number;

export { type EastAsianWidth, computeWidth, version as eawVersion, getEAW, getEAWOfCodePoint };