Function isLetter

js/remarkable.js:5013–5017

(ch)

var HTML_TAG_CLOSE_RE = /^<\/([a-zA-Z]{1,15})[\s>]/;

function isLetter(ch) {
  /*eslint no-bitwise:0*/
  var lc = ch | 0x20; // to lower case
  return (lc >= 0x61/* a */) && (lc <= 0x7a/* z */);
}

module.exports = function htmlblock(state, startLine, endLine, silent) {
  var ch, match, nextLine,