locutus/esm/php/_helpers/_arrayPointers.js

Locutus other languages' standard libraries to JavaScript for fun and educational purposes

import { ensurePhpRuntimeState } from "./_phpRuntimeState.js";
import { entriesOfPhpAssoc } from "./_phpTypes.js";
const findPointerIndex = (pointers, target) => {
    for (let index = 0; index < pointers.length; index += 1) {
        if (pointers[index] === target) {
            return index;
        }
    }
    return -1;
};
export function getPointerState(target, initialize = true) {
    const runtime = ensurePhpRuntimeState();
    const pointers = runtime.pointers;
    // Store [target, cursor] pairs in one flat runtime list so pointer state stays bound to each array-like input.
    const pointerTarget = target;
    let index = findPointerIndex(pointers, pointerTarget);
    if (index === -1) {
        if (!initialize) {
            return null;
        }
        pointers.push(pointerTarget, 0);
        index = pointers.length - 2;
    }
    const cursorValue = pointers[index + 1];
    const cursor = typeof cursorValue === 'number' ? cursorValue : 0;
    return {
        cursor,
        setCursor: (nextCursor) => {
            pointers[index + 1] = nextCursor;
        },
    };
}
export function getArrayLikeLength(target) {
    if (Array.isArray(target)) {
        return target.length;
    }
    let count = 0;
    for (const _key in target) {
        count += 1;
    }
    return count;
}
export function getEntryAtCursor(target, cursor) {
    if (cursor < 0) {
        return null;
    }
    if (Array.isArray(target)) {
        if (cursor >= target.length) {
            return null;
        }
        const value = target[cursor];
        if (typeof value === 'undefined') {
            return null;
        }
        return [cursor, value];
    }
    let index = 0;
    for (const [key, value] of entriesOfPhpAssoc(target)) {
        if (index === cursor) {
            return [key, value];
        }
        index += 1;
    }
    return null;
}