JavaScript function for parsing simple YAML (supports only strings, lists, dicts)

yaml_loads.js

// based on simplified version of Python snippet: https://gist.github.com/vadimkantorov/b26eda3645edb13feaa62b874a3e7f6f

function yaml_loads(frontamtter_str)
{
  const procval = s => (s.length >= 2 && s[0] == '"' && s[s.length - 1] == '"') ? s.slice(1, s.length - 1) : (s.length >= 2 && s[0] == "'" && s[s.length - 1] == "'") ? s.slice(1, s.length - 1) : s;

  for(const line of frontmatter_str.split('\n'))
  {
      const line_strip = line.trim();
      const is_list_item = line_strip.startsWith('- ');
      if(!line || line.startsWith('#'))
          continue;

      const colonIdx = line.indexOf(':');
      const key = colonIdx != -1 ? line.slice(0, colonIdx).trim() : '';
      const val = colonIdx != -1 ? line.substring(1 + colonIdx).trim() : is_list_item ? line_strip.substring(2).trim() : '';

      if(colonIdx != -1)
      {
          if(!frontmatter)
              frontmatter = {};
          frontmatter[key] = val ? procval(val) : [];
      }
      else if(is_list_item)
      {
          if(!frontmatter)
              frontmatter = {};
          if(!front_matter[key])
              frontmatter[key] = [];
          frontmatter[key].push(procval(val));
      }
  }
  return frontmatter;
}