code: function(walk) {
          if (!walk.at('{/')) return false;
          var endIdx = walk.indexOf('}');
          if (endIdx === null)
            return false;
          var source = walk.substring(walk.position, endIdx + 1);
          // Test against the regex
          var m = inputRegexRe.exec(source);
          if (!m) return false;
          // We got an input
          var ctl = this.formCompiler.createCtl('inputRegex');
          try {
            var flags = m[2] || undefined;
            ctl.value = new RegExp('^' + m[1].replace(/^\^/, '').replace(/\$$/, '') + '$', flags);
          } catch(e) {
            return false;
          }
          var size = m[3] && parseInt(m[3].substring(1).trim()) || m[1].length;
          this.out.push('<input');
          this.emitAttrs({
            id: ctl.id,
            name: ctl.id,
            class: ctl.type,
            type: 'text',
            size: size
          });
          this.out.push('/>');
          walk.startFrom(endIdx).skip(2);
          return true;
        }
docs: Input regex starts with `{/` marker and ends with `/[flags][, size]}`.