code: function captureExpressions(expressionChain, booleans) {
          var expressions, re;
  
          if (booleans) {
              re = new RegExp(PREFIX + booleans.join(INFIX) + POSTFIX, 'i');
              expressions = expressionChain.match(re);
              expressions.shift(); // discard [0] (input)
          } else {
              expressions = [expressionChain];
          }
  
          return expressions;
      }
docs: Break an expression chain into a list of expressions.
  @param {string} expressionChain
  @returns {string[]}