@thi.ng/transclude/tpl/markdown.js

Extensible functional template engine for text document generation, incl. various high-level Markdown features

import { repeat } from "@thi.ng/strings/repeat";
import { slugifyGH } from "@thi.ng/strings/slugify";
import { split } from "@thi.ng/strings/split";
import { comp } from "@thi.ng/transducers/comp";
import { filter } from "@thi.ng/transducers/filter";
import { map } from "@thi.ng/transducers/map";
import { str } from "@thi.ng/transducers/str";
import { transduce } from "@thi.ng/transducers/transduce";
const image = (url, alt = "") => `![${alt}](${url})`;
const link = (title, href) => `[${title}](${href})`;
const list = (items, eol = "\n") => transduce(
  map((x) => `- ${x}`),
  str(eol),
  items
);
const toc = (opts = {}) => ({ src, eol }) => {
  const {
    min = 2,
    max = 4,
    match = /<!-- toc -->/i,
    disable = /<!-- notoc -->/i,
    title
  } = opts;
  const isHeading = new RegExp(`^#{${min},${max}}\\s`);
  const reHeading = new RegExp(`^(#{${min},${max}})\\s(.+)`);
  const toc2 = transduce(
    comp(
      filter((line) => isHeading.test(line) && !disable.test(line)),
      map((hd) => {
        const [_, level, title2] = reHeading.exec(hd);
        const indent = repeat(
          "  ",
          Math.max(0, level.length - min)
        );
        return `${indent}- ${link(title2, `#${slugifyGH(title2)}`)}`;
      })
    ),
    str(eol),
    split(src)
  );
  return src.replace(match, title ? title + toc2 : toc2);
};
export {
  image,
  link,
  list,
  toc
};