Add pipeline operator code janl#691

Author: bren-do

mustache.js

@@ -81,6 +81,7 @@ var spaceRe = /\s+/;
 var equalsRe = /\s*=/;
 var curlyRe = /\s*\}/;
 var tagRe = /#|\^|\/|>|\{|&|=|!/;
+var pipelineRe = /\|\>/;
 
 /**
  * Breaks up the given `template` string into a tree of tokens. If the `tags`
@@ -398,11 +399,46 @@ Context.prototype.push = function push(view) {
   return new Context(view, this);
 };
 
+Context.prototype.resolvePipelineOperator = function resolvePipelineOperator(
+  value,
+  pipelines,
+) {
+  var self = this;
+  var pipelineResolver = function pipelineResolver(val, func) {
+    var findFunction = function (
+      instance,
+      functionToFind,
+      valueToPutInFoundFunction,
+      depth,
+    ) {
+      if (depth <= 0 || !instance) return null;
+      if (instance.view.hasOwnProperty(functionToFind))
+        return instance.view[func](valueToPutInFoundFunction);
+
+      return findFunction(instance.parent, functionToFind, val, depth);
+    };
+
+    var foundFunction = findFunction(self, func, val, 20);
+
+    return foundFunction ? foundFunction : val;
+  };
+  return pipelines.reduce(pipelineResolver, value);
+};
+
 /**
  * Returns the value of the given name in this context, traversing
  * up the context hierarchy if the value is absent in this context's view.
  */
 Context.prototype.lookup = function lookup(name) {
+  // {{variable |> pipelineOne |> pipelineTwo}}
+  // output: [variable,pipelineOne, pipelineTwo ]
+  var replacedName = name
+    .replace(new RegExp(spaceRe, "g"), "")
+    .split(pipelineRe);
+
+  name = replacedName.shift();
+  var pipelines = replacedName;
+
   var cache = this.cache;
 
   var value;
@@ -484,6 +520,10 @@ Context.prototype.lookup = function lookup(name) {
 
   if (isFunction(value)) value = value.call(this.view);
 
+  if (pipelines) {
+    value = this.resolvePipelineOperator(value, pipelines);
+  }
+
   return value;
 };