mathup/src/compiler/transformer/index.js

Easy MathML authoring tool with a quick to write syntax

import transforms from "./transforms/index.js";

/**
 * @typedef {import("../parser/index.js").Node} ASTNode
 * @typedef {object} TransformerOptions
 * @property {"ltr" | "rtl" | null} [dir=null] - The reading direction of the
 *   output. Default is `null`
 * @property {"block" | "inline" | null} [display=null] - Whether the expression
 *   should be in display mode. Default is `null` Default is `null` Default is
 *   `null` Default is `null`
 * @typedef {object} Tag
 * @property {string} tag
 * @property {Record<string, string | number | boolean | undefined | null>} [attrs]
 * @property {(Tag | null)[]} [childNodes]
 * @property {string} [textContent]
 */

/**
 * @template {ASTNode} [Node=ASTNode] Default is `ASTNode`
 * @typedef {(
 *   node: Node,
 *   transform: (node: ASTNode) => Tag | null,
 *   options: Required<TransformerOptions>,
 * ) => Tag | null} TransformFn
 */

/**
 * @param {Required<TransformerOptions>} options
 * @returns {(node: ASTNode) => Tag | null}
 */
export default function transformer(options) {
  return function transform(node) {
    const transformNode = transforms.get(node.type);

    if (!transformNode) {
      return null;
    }

    return transformNode(node, transform, options);
  };
}