update two-way prop binding type indicator from @ to &

Author: yyx990803

examples/modal/index.html

@@ -58,7 +58,7 @@
     <div id="app">
       <button id="show-modal" @click="showModal = true">Show Modal</button>
       <!-- use the modal component, pass in the prop -->
-      <modal :show@="showModal">
+      <modal :show&="showModal">
         <!--
           you can use custom content here to overwrite
           default content

src/compiler/compile-props.js

@@ -104,7 +104,7 @@ module.exports = function compileProps (el, propOptions) {
     } else {
       // new syntax, check binding type
       if ((value = _.getBindAttr(el, attr)) === null) {
-        if ((value = _.getBindAttr(el, attr + '@')) !== null) {
+        if ((value = _.getBindAttr(el, attr + '&')) !== null) {
           prop.mode = propBindingModes.TWO_WAY
         } else if ((value = _.getBindAttr(el, attr + '*')) !== null) {
           prop.mode = propBindingModes.ONE_TIME

src/parsers/text.js

@@ -73,7 +73,7 @@ exports.parse = function (text) {
     value = html ? match[1] : match[2]
     first = value.charCodeAt(0)
     oneTime = first === 42 // *
-    twoWay = first === 64  // @
+    twoWay = first === 38 || first === 64 // & or @
     value = oneTime || twoWay
       ? value.slice(1)
       : value

test/unit/specs/compiler/compile_spec.js

@@ -313,8 +313,8 @@ if (_.inBrowser) {
         'v-bind:test-normal="a" ' +
         'test-literal="1" ' +
         ':optimize-literal="1" ' +
-        ':test-two-way@="a" ' +
-        ':two-way-warn@="a + 1" ' +
+        ':test-two-way&="a" ' +
+        ':two-way-warn&="a + 1" ' +
         ':test-one-time*="a"></div>'
       compiler.compileAndLinkProps(vm, el.firstChild, props)
       expect(vm._bindDir.calls.count()).toBe(3) // skip literal and one time

test/unit/specs/directives/prop_spec.js

@@ -99,7 +99,7 @@ if (_.inBrowser) {
             a: 'A'
           }
         },
-        template: '<test v-bind:testt@="test" :bb@="b" :a@=" test.a " v-ref="child"></test>',
+        template: '<test v-bind:testt&="test" :bb&="b" :a&=" test.a " v-ref="child"></test>',
         components: {
           test: {
             props: ['testt', 'bb', 'a'],
@@ -245,7 +245,7 @@ if (_.inBrowser) {
         data: {
           b: 'B'
         },
-        template: '<test :b@="b + \'B\'" v-ref="child"></test>',
+        template: '<test :b&="b + \'B\'" v-ref="child"></test>',
         components: {
           test: {
             props: ['b'],