gen-slides

#!/usr/bin/env node

const fs = require('fs');
const _ = require('./js/underscore-min.js');

var inCodeBlock = false;
var out =
  '<!--\n' +
  '****    THIS IS A GENERATED FILE, DO NOT EDIT!    ****\n' +
  '**** CHANGES SHOULD BE MADE IN slides.md INSTEAD! ****\n' +
  '-->\n';

// Escape HTML in code blocks except for spans to allow for fragment/mark.
// The trailing dots are needed due to js' clunky indent rules.
const escapeCodeBlock = s =>
  _.escape(s).
    replace(/&lt;frag&gt;/g, '<span class="fragment">').
    replace(/&lt;frag (\d+)&gt;/g, '<span class="fragment" data-fragment-index="$1">').
    replace(/&lt;mark&gt;/g, '<span class="fragment highlight-red">').
    replace(/&lt;mark (\d+)&gt;/g, '<span class="fragment highlight-red" data-fragment-index="$1">').
    replace(/&lt;mark (\w+)&gt;/g, '<span class="fragment highlight-$1">').
    replace(/&lt;mark (\w+) (\d+)&gt;/g, '<span class="fragment highlight-$1" data-fragment-index="$2">').
    replace(/&lt;\/(frag|mark)&gt;/g, '</span>');

// Expand non-code block <frag> elements
const expandMagicTags = s =>
  s.replace(/<frag>/g, '<span class="fragment">').
    replace(/<frag (\d+)>/g, '<span class="fragment" data-fragment-index="$1">').
    replace(/<\/frag>/g, '</span>')
    ;

fs.readFileSync('./slides.md').toString().split('\n').forEach(line => {
  var matcher = /^```(.*)$/.exec(line);
  if (matcher === null) {
    if (inCodeBlock) {
      out += escapeCodeBlock(line) + '\n';
    } else {
      out += expandMagicTags(line) + '\n';
    }
    return;
  }
  if (inCodeBlock) {
    inCodeBlock = false;
    out += '</code></pre>\n'
    return;
  }
  inCodeBlock = true;
  out += '<pre><code data-noescape data-trim class=' + matcher[1] + '>\n';
});

fs.writeFile('slides.gen.md', out, err => { if (err) console.log(err); });

console.log('Generated slides.gen.md');