@thi.ng/hiccup-markdown/serialize.js

Markdown parser & serializer from/to Hiccup format

import { implementsFunction } from "@thi.ng/checks/implements-function";
import { isFunction } from "@thi.ng/checks/is-function";
import { isNotStringAndIterable } from "@thi.ng/checks/is-not-string-iterable";
import { isString } from "@thi.ng/checks/is-string";
import { DEFAULT, defmulti } from "@thi.ng/defmulti/defmulti";
import { illegalArgs } from "@thi.ng/errors/illegal-arguments";
import { normalize } from "@thi.ng/hiccup/normalize";
import { repeat } from "@thi.ng/strings/repeat";
import { wrap } from "@thi.ng/strings/wrap";
import { Border } from "@thi.ng/text-canvas/api";
import { formatCanvas } from "@thi.ng/text-canvas/format";
import { tableCanvas } from "@thi.ng/text-canvas/table";
const serialize = (tree, ctx) => __serialize(tree, ctx, { indent: 0, sep: "" }).replace(/\n{3,}/g, "\n\n").trim();
const __serialize = (tree, ctx, state) => tree == null ? "" : Array.isArray(tree) ? __serializeArray(tree, ctx, state) : isFunction(tree) ? __serialize(tree(ctx), ctx, state) : implementsFunction(tree, "toHiccup") ? __serialize(tree.toHiccup(ctx), ctx, state) : implementsFunction(tree, "deref") ? __serialize(tree.deref(), ctx, state) : isNotStringAndIterable(tree) ? __serializeIter(tree, ctx, state) : tree.toString();
const __serializeArray = (tree, ctx, state) => {
  if (!tree.length) return "";
  let tag = tree[0];
  return isFunction(tag) ? __serialize(tag.apply(null, [ctx, ...tree.slice(1)]), ctx, state) : implementsFunction(tag, "render") ? __serialize(
    tag.render.apply(null, [ctx, ...tree.slice(1)]),
    ctx,
    state
  ) : isString(tag) ? __serializeTreeElement(tree, ctx, state) : isNotStringAndIterable(tree) ? __serializeIter(tree, ctx, state) : illegalArgs(`invalid tree node: ${tree}`);
};
const __serializeTreeElement = (tree, ctx, state) => {
  tree = normalize(tree);
  const attribs = tree[1];
  return attribs.__skip || attribs.__serialize === false ? "" : serializeElement(tree, ctx, state);
};
const __serializeIter = (iter, ctx, state) => {
  if (!iter) return "";
  const res = [];
  for (const i of iter) {
    res.push(__serialize(i, ctx, state));
  }
  return res.join(state.sep);
};
const __heading = (level) => (el, ctx, state) => `
${repeat("#", level)} ${__body(el, ctx, state)}
`;
const __body = (el, ctx, state) => __serializeIter(el[2], ctx, state);
const __resolve = (x) => isFunction(x) ? x() : x;
const serializeElement = defmulti(
  (el) => el[0],
  {
    th: "strong"
  },
  {
    [DEFAULT]: __body,
    h1: __heading(1),
    h2: __heading(2),
    h3: __heading(3),
    h4: __heading(4),
    h5: __heading(5),
    h6: __heading(6),
    p: (el, ctx, state) => `
${__body(el, ctx, state)}
`,
    img: (el) => `![${el[1].alt || ""}](${el[1].src})`,
    a: (el, ctx, state) => {
      let { href, title } = el[1];
      title = __resolve(title);
      return `[${__body(el, ctx, state)}](${__resolve(href)}${title ? ` "${title}"` : ""})`;
    },
    em: (el, ctx, state) => `_${__body(el, ctx, state)}_`,
    strong: (el, ctx, state) => `**${__body(el, ctx, state)}**`,
    pre: (el, ctx, state) => `
\`\`\`${el[1].lang || ""}
${__body(el, ctx, {
      ...state,
      pre: true,
      sep: "\n"
    })}
\`\`\`
`,
    code: (el, ctx, state) => state.pre ? el[2][0] : `\`${__body(el, ctx, state)}\``,
    ul: (el, ctx, state) => {
      const cstate = {
        ...state,
        indent: state.indent + 4,
        sep: "\n"
      };
      return wrap(state.indent === 0 ? "\n" : "")(
        __body(el, ctx, cstate)
      );
    },
    ol: (el, ctx, state) => {
      const cstate = {
        ...state,
        indent: state.indent + 4,
        id: 0,
        sep: "\n"
      };
      return wrap(state.indent === 0 ? "\n" : "")(
        __body(el, ctx, cstate)
      );
    },
    li: (el, ctx, state) => repeat(" ", state.indent - 4) + (state.id != null ? ++state.id + "." : "-") + " " + __body(el, ctx, { ...state, sep: "" }),
    blockquote: (el, ctx, state) => `
${repeat(">", state.indent + 1)} ${__body(el, ctx, {
      ...state,
      indent: state.indent + 1,
      blockquote: true
    })}
`,
    br: (_, __, state) => state.blockquote ? `\\
${repeat(">", state.indent)} ` : "\\\n",
    hr: () => "\n---\n",
    table: (el, ctx, state) => {
      let caption = "";
      let thead = [];
      let tbody = [];
      let colWidths = [];
      const rows = (rows2) => rows2.map(
        (x) => normalize(x)[2].map((td, i) => {
          const cell = serialize(td, ctx);
          colWidths[i] = Math.max(colWidths[i] || 3, cell.length);
          return cell;
        })
      );
      for (let child of el[2]) {
        child = normalize(child);
        switch (child[0]) {
          case "thead":
            thead = rows(child[2]);
            break;
          case "tbody":
            tbody = rows(child[2]);
            break;
          case "caption":
            caption = __body(child, ctx, state);
            break;
          default:
        }
      }
      return "\n" + formatCanvas(
        tableCanvas(
          {
            cols: colWidths.map((width) => ({ width })),
            padding: [1, 0],
            border: Border.V
          },
          [
            ...thead,
            colWidths.map((w) => repeat("-", w)),
            ...tbody
          ]
        )
      ) + "\n" + caption + "\n";
    }
  }
);
export {
  serialize,
  serializeElement
};