examples/verbal.html

<!doctype html>
<html>
  <head>
    <title>State with squishy-pants.js</title>
    <meta charset="utf-8" />
    <link href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.3.1/css/bootstrap-combined.min.css" rel="stylesheet">
    <script src="../squishy-pants.js"></script>
    <script>
      function event(element, name, callback) {
          if(element.addEventListener) {
              element.addEventListener(name, callback, false);
          } else {
              element.attachEvent('on' + name, callback);
          }
      }

      event(window, 'load', function() {
          var _ = squishy,
              log = _.IO(_.constant(function(x) {
                  document.getElementById('output').innerHTML += x + '<br />';
              })),
              logger = _.curry(function(prefix, value) {
                  log.ap(_.IO.of(prefix + ' > ' + value)).unsafePerform();
              }),
              result;

          function snd(t) {
              return t._2;
          }

          function discard(a, b) {
              return a.chain(function() {
                  return b;
              });
          }

          function replicate(a, x) {
              var r = [],
                  i;

              for(i = 0; i < a.length; i++) {
                  r.push(x(a[i]));
              }
              return r;
          }

          function next(f) {
              return discard(
                  _.State.modify(function(t) {
                      return _.Tuple2(t._1, t._2 + f());
                  }),
                  _.State.get.map(snd)
              );
          }

          function verbal() {
              var args = [].slice.call(arguments),
                  result = _.reduce(
                      replicate(args, next),
                      function(a, b) {
                          return discard(a, b);
                      }
                  ).evalState(_.Tuple2('', ''));

              return new RegExp(result, 'gm');
          }

          function sanitize(value) {
              return value.replace(
                  /[^\w]/g,
                  function(character) {
                      return "\\" + character;
                  }
              );
          }

          function startWith(value) {
              return function() {
                  return '^' + then(value)();
              };
          }

          function endWith(value) {
              return function() {
                  return then(value)() + '$';
              };
          }

          function then(value) {
              return function() {
                  return '(?:' + sanitize(value) + ')';
              };
          }

          function maybe(value) {
              return function() {
                  return '(?:' + sanitize(value) + ')?';
              };
          }

          function anythingBut(value) {
              return function() {
                  return '(?:[^' + sanitize(value) + ']*)';
              };
          }

          result = verbal(
                        startWith('http'),
                        maybe('s'),
                        then('://'),
                        maybe('www.'),
                        anythingBut(' ')
                    );

          logger('--', result);
      });

    </script>
  </head>
  <body>
    <div class="container">
      <div class="row">
        <div class="span8 offset2">
          <h1>State using <a href="https://github.com/SimonRichardson/squishy-pants">squishy-pants.js</a></h1>
          <hr />
          <div class="alert">
              <pre>
    verbal(
        startWith('http'),
        maybe('s'),
        then('://'),
        maybe('www.'),
        anythingBut(' ')
    );
              </pre>
          </div>
          <hr />
          <p>Becomes:</p>
          <div class="alert" id="output"></div>
        </div>
      </div>
    </div>
  </body>
</html>