Replace 'iff' with 'if and only if'

src/lib/custom-style.html

@@ -129,7 +129,8 @@
         this.__appliedElement.__cssBuild = this.__cssBuild;
       }
       // needed becuase elements in imports do not get 'attached'
-      // TODO(sorvell): we could only do this iff this.ownerDocument != document;
+      // TODO(sorvell): we could only do this if and only if
+      // this.ownerDocument != document;
       // however, if we do that, we also have to change the `attached`
       // code to go at `_beforeAttached` time because this is when 
       // elements produce styles (otherwise this breaks @apply shim)
@@ -144,7 +145,8 @@
 
     _tryApply: function() {
       if (!this._appliesToDocument) {
-        // only apply variables iff this style is not inside a dom-module
+        // only apply variables if and only if this style is not inside
+        // a dom-module
         if (this.parentNode &&
           (this.parentNode.localName !== 'dom-module')) {
           this._appliesToDocument = true;

src/lib/dom-api-shady.html

@@ -45,8 +45,8 @@
     },
 
     // cases in which we may not be able to just do standard native call
-    // 1. container has a shadyRoot (needsDistribution IFF the shadyRoot
-    // has an insertion point)
+    // 1. container has a shadyRoot (needsDistribution if and only if the
+    // shadyRoot has an insertion point)
     // 2. container is a shadyRoot (don't distribute, instead set
     // container to container.host.
     // 3. node is <content> (host of container needs distribution)
@@ -55,7 +55,7 @@
         throw Error('The ref_node to be inserted before is not a child ' +
           'of this node');
       }
-      // remove node from its current position iff it's in a tree.
+      // remove node from its current position if and only if it's in a tree.
       if (node.nodeType !== Node.DOCUMENT_FRAGMENT_NODE) {
         var parent = TreeApi.Logical.getParentNode(node);
         // notify existing parent that this node is being removed.
@@ -87,15 +87,15 @@
     },
 
     // Try to add node. Record logical info, track insertion points, perform
-    // distribution iff needed. Return true if the add is handled.
+    // distribution if and only if needed. Return true if the add is handled.
     _addNode: function(node, ref_node) {
       var root = this.getOwnerRoot();
       if (root) {
         // note: we always need to see if an insertion point is added
         // since this saves logical tree info; however, invalidation state
         // needs
         var ipAdded = this._maybeAddInsertionPoint(node, this.node);
-        // invalidate insertion points IFF not already invalid!
+        // invalidate insertion points if and only if not already invalid!
         if (!root._invalidInsertionPoints) {
           root._invalidInsertionPoints = ipAdded;
         }
@@ -110,7 +110,8 @@
       // if shady is handling this node,
       // the actual dom may not be removed if the node or fragment contents
       // remain undistributed so we ensure removal here.
-      // NOTE: we only remove from existing location iff shady dom is involved.
+      // NOTE: we only remove from existing location if and only if shady dom is
+      // involved.
       // This is because a node fragment is passed to the native add method
       // which expects to see fragment children. Regular elements must also
       // use this check because not doing so causes separation of
@@ -154,8 +155,8 @@
       return node;
     },
 
-    // Try to remove node: update logical info and perform distribution iff
-    // needed. Return true if the removal has been handled.
+    // Try to remove node: update logical info and perform distribution if and
+    // only if needed. Return true if the removal has been handled.
     // note that it's possible for both the node's host and its parent
     // to require distribution... both cases are handled here.
     _removeNode: function(node) {
@@ -165,10 +166,10 @@
       var distributed;
       var root = this._ownerShadyRootForNode(node);
       if (logicalParent) {
-        // distribute node's parent iff needed
+        // distribute node's parent if and only if needed
         distributed = dom(node)._maybeDistributeParent();
         TreeApi.Logical.recordRemoveChild(node, logicalParent);
-        // remove node from root and distribute it iff needed
+        // remove node from root and distribute it if and only if needed
         if (root && this._removeDistributedChildren(root, node)) {
           root._invalidInsertionPoints = true;
           this._lazyDistribute(root.host);

src/lib/experimental/patch-dom.html

@@ -241,7 +241,7 @@
 
   // NOTE: patch logical implementations here so we can use 
   // composed getters
-  // TODO(sorvell): may need to patch saveChildNodes iff the tree has
+  // TODO(sorvell): may need to patch saveChildNodes if and only if the tree has
   // already been distributed.
   TreeApi.Logical.recordInsertBefore = function(node, container, ref_node) {
     container.__dom.childNodes = null;

src/lib/template/dom-if.html

@@ -13,7 +13,7 @@
 <script>
 
   /**
-   * Stamps the template iff the `if` property is truthy.
+   * Stamps the template if and only if the `if` property is truthy.
    *
    * When `if` becomes falsey, the stamped content is hidden but not
    * removed from dom. When `if` subsequently becomes truthy again, the content

src/mini/shady.html

@@ -30,7 +30,7 @@
     Polymer.Base._addFeature({
 
       _prepShady: function() {
-        // Use this system iff localDom is needed.
+        // Use this system if and only if localDom is needed.
         this._useContent = this._useContent || Boolean(this._template);
       },
 

src/standard/gestures.html

@@ -547,7 +547,7 @@
           // first move is 'start', subsequent moves are 'move', mouseup is 'end'
           self.info.state = self.info.started ? (e.type === 'mouseup' ? 'end' : 'track') : 'start';
           if (self.info.state === 'start') {
-            // iff tracking, always prevent tap
+            // if and only if tracking, always prevent tap
             Gestures.prevent('tap');
           }
           self.info.addMove({x: x, y: y});
@@ -586,7 +586,7 @@
       var x = ct.clientX, y = ct.clientY;
       if (this.hasMovedEnough(x, y)) {
         if (this.info.state === 'start') {
-          // iff tracking, always prevent tap
+          // if and only if tracking, always prevent tap
           Gestures.prevent('tap');
         }
         this.info.addMove({x: x, y: y});

src/standard/styling.html

@@ -81,7 +81,7 @@
             styleTransformer.elementStyles(this);
           // prepare to shim style properties.
           this._prepStyleProperties();
-          // apply static styles iff
+          // apply static styles if and only if
           // no custom properties are used (otherwise
           // styles are applied via property shimming)
           if (!this._needsStyleProperties() && cssText){

src/standard/x-styling.html

@@ -67,8 +67,8 @@
         this._customStyle = null;
       },
 
-      // TODO(dfreedm): should only be true iff browser doesn't support
-      // native custom properties.
+      // TODO(dfreedm): should only be true if and only if browser doesn't
+      // support native custom properties.
       _needsStyleProperties: function() {
         return Boolean(!nativeVariables && this._ownStylePropertyNames &&
           this._ownStylePropertyNames.length);
@@ -226,8 +226,8 @@
             value = host._scopeElementClass(node, value);
           }
         }
-        // note: using Polymer.dom here ensures that any attribute sets
-        // will provoke distribution if necessary; do this iff necessary
+        // note: using Polymer.dom here ensures that any attribute sets will
+        // provoke distribution if necessary; do this if and only if necessary
         node = (this.shadyRoot && this.shadyRoot._hasDistributed) ?
           Polymer.dom(node) : node;
         serializeValueToAttribute.call(this, value, attribute, node);
@@ -263,7 +263,7 @@
         if (nativeVariables) {
           propertyUtils.updateNativeStyleProperties(this, this.customStyle);
         } else {
-          // actually process styling changes iff attached
+          // actually process styling changes if and only if attached
           if (this.isAttached) {
             // skip applying properties to self if not used
             if (this._needsStyleProperties()) {