Nitpicky comment fixes

Summary:
Mainly this addresses clarity of a few comments, line breaks at weird places, and style differences within a single file.

Just comments and including JetBrains `.idea` config folder in the `gitignore`.

- [X] All tests pass. Demo project builds and runs.
- [X] I added tests, an experiment, or detailed why my change isn't tested.
- [N/A] I added an entry to the `CHANGELOG.md` for any breaking changes, enhancements, or bug fixes.
- [N/A] I have reviewed the [contributing guide](https://github.com/Instagram/IGListKit/blob/master/.github/CONTRIBUTING.md)
Closes Instagram#600

Differential Revision: D4810628

Pulled By: jessesquires

fbshipit-source-id: fce445c0253f592a43045ae098e440d41c166993

.gitignore

@@ -52,3 +52,6 @@ Carthage/Build
 # Bundler
 .bundle
 vendor
+
+# Jetbrains
+.idea

Source/IGListAdapter.h

@@ -24,9 +24,9 @@
 NS_ASSUME_NONNULL_BEGIN
 
 /**
- A block to execute when list updates completes.
+ A block to execute when the list updates are completed.
 
- @param finished Specifies whether or not the updates finished.
+ @param finished Specifies whether or not the update animations completed successfully.
  */
 typedef void (^IGListUpdaterCompletion)(BOOL finished);
 
@@ -52,7 +52,7 @@ IGLK_SUBCLASSING_RESTRICTED
 @property (nonatomic, nullable, weak) IGListCollectionView *collectionView;
 
 /**
- The object that acts as the data source for the list adapter.
+ The object that acts as the data source for the adapter.
  */
 @property (nonatomic, nullable, weak) id <IGListAdapterDataSource> dataSource;
 
@@ -74,7 +74,7 @@ IGLK_SUBCLASSING_RESTRICTED
 @property (nonatomic, nullable, weak) id <UIScrollViewDelegate> scrollViewDelegate;
 
 /**
- The updater for this list adapter.
+ The updater for the adapter.
  */
 @property (nonatomic, strong, readonly) id <IGListUpdatingDelegate> updater;
 
@@ -104,11 +104,11 @@ IGLK_SUBCLASSING_RESTRICTED
                workingRangeSize:(NSInteger)workingRangeSize NS_DESIGNATED_INITIALIZER;
 
 /**
- Perform an update from the previous state of the data source. This is analagous to calling
+ Perform an update from the previous state of the data source. This is analogous to calling
  `-[UICollectionView performBatchUpdates:completion:]`.
 
  @param animated   A flag indicating if the transition should be animated.
- @param completion The block to execute when the update completes.
+ @param completion The block to execute when the updates complete.
  */
 - (void)performUpdatesAnimated:(BOOL)animated completion:(nullable IGListUpdaterCompletion)completion;
 
@@ -131,7 +131,7 @@ IGLK_SUBCLASSING_RESTRICTED
  
  @param section A section in the list.
 
- @return An section controller or `nil` if the section does not exist.
+ @return A section controller or `nil` if the section does not exist.
  */
 - (nullable IGListSectionController <IGListSectionType> *)sectionControllerForSection:(NSInteger)section;
 
@@ -149,7 +149,7 @@ IGLK_SUBCLASSING_RESTRICTED
 
  @param object An object from the data source.
 
- @return An section controller or `nil` if `object` is not in the list.
+ @return A section controller or `nil` if `object` is not in the list.
 
  @see `-[IGListAdapterDataSource listAdapter:sectionControllerForObject:]`
  */
@@ -160,7 +160,7 @@ IGLK_SUBCLASSING_RESTRICTED
  
  @param sectionController A section controller in the list.
  
- @return The object for the specified section controller, or nil if not found.
+ @return The object for the specified section controller, or `nil` if not found.
  */
 - (nullable id)objectForSectionController:(IGListSectionController <IGListSectionType> *)sectionController;
 
@@ -183,7 +183,7 @@ IGLK_SUBCLASSING_RESTRICTED
 - (NSInteger)sectionForObject:(id)object;
 
 /**
- Returns a copy of all the objects currently powering the adapter.
+ Returns a copy of all the objects currently driving the adapter.
 
  @return An array of objects.
  */
@@ -213,7 +213,7 @@ IGLK_SUBCLASSING_RESTRICTED
 - (NSArray<UICollectionViewCell *> *)visibleCellsForObject:(id)object;
 
 /**
- Scrolls to the sepcified object in the list adapter.
+ Scrolls to the specified object in the list adapter.
 
  @param object             The object to which to scroll.
  @param supplementaryKinds The types of supplementary views in the section.

Source/IGListAdapterDataSource.h

@@ -45,7 +45,7 @@ NS_ASSUME_NONNULL_BEGIN
 
  Section controllers are initialized for all objects whenever the `IGListAdapter` is created, updated, or reloaded.
  Section controllers are reused when objects are moved or updated. Maintaining the `-[IGListDiffable diffIdentifier]`
- guarentees this.
+ guarantees this.
  */
 - (IGListSectionController <IGListSectionType> *)listAdapter:(IGListAdapter *)listAdapter sectionControllerForObject:(id)object;
 

Source/IGListAdapterUpdater.h

@@ -18,7 +18,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 /**
  An `IGListAdapterUpdater` is a concrete type that conforms to `IGListUpdatingDelegate`.
- It is an out-of-box upater for `IGListAdapter` objects to use.
+ It is an out-of-box updater for `IGListAdapter` objects to use.
 
  @note This updater performs re-entrant, coalesced updating for a list. It also uses a least-minimal diff 
  for calculating UI updates when `IGListAdapter` calls 

Source/IGListAdapterUpdater.m

@@ -65,7 +65,7 @@ - (void)performReloadDataWithCollectionView:(UICollectionView *)collectionView {
     }
 
     // execute all stored item update blocks even if we are just calling reloadData. the actual collection view
-    // mutations will be discarded, but clients are encouraged to put their actually /data/ mutations inside the
+    // mutations will be discarded, but clients are encouraged to put their actual /data/ mutations inside the
     // update block as well, so if we don't execute the block the changes will never happen
     for (IGListItemUpdateBlock itemUpdateBlock in batchUpdates.itemUpdateBlocks) {
         itemUpdateBlock();
@@ -305,7 +305,7 @@ - (void)cleanStateBeforeUpdates {
     // remove indexpath/item changes
     self.objectTransitionBlock = nil;
 
-    // removes all object completion blocks. done before updates to start collecting completion blocks for coaslesced
+    // removes all object completion blocks. done before updates to start collecting completion blocks for coalesced
     // or re-entrant object updates
     [self.completionBlocks removeAllObjects];
 }

Source/IGListAdapterUpdaterDelegate.h

@@ -29,7 +29,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)listAdapterUpdater:(IGListAdapterUpdater *)listAdapterUpdater willPerformBatchUpdatesWithCollectionView:(UICollectionView *)collectionView;
 
 /**
- Notifies the delegate that the updater succesfully finished `-[UICollectionView performBatchUpdates:completion:]`.
+ Notifies the delegate that the updater successfully finished `-[UICollectionView performBatchUpdates:completion:]`.
 
  @param listAdapterUpdater The adapter updater owning the transition.
  @param updates            The batch updates that were applied to the collection view.

Source/IGListBindable.h

@@ -19,7 +19,7 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  Tells the cell to configure itself with the given view model.
 
- @param viewModel The view model for the cel.
+ @param viewModel The view model for the cell.
 
  @note The view model can change many times throughout the lifetime of a cell as the model values change and the cell
  is reused. Implementations should use only this method to do their configuration.

Source/IGListCollectionContext.h

@@ -102,7 +102,7 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  Returns the section index of an section controller.
 
- @param sectionController An section controller object.
+ @param sectionController A section controller object.
 
  @return The section index of the controller if found, otherwise `NSNotFound`.
  */
@@ -156,10 +156,10 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  Dequeues a supplementary view from the collection view reuse pool.
 
- @param elementKind       The kind of supplementary veiw.
+ @param elementKind       The kind of supplementary view.
  @param sectionController The section controller requesting this information.
  @param viewClass         The class of the supplementary view.
- @param index             The index of the supplementary vew.
+ @param index             The index of the supplementary view.
 
  @return A supplementary view dequeued from the reuse pool or a newly created one.
 
@@ -173,10 +173,10 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  Dequeues a supplementary view from the collection view reuse pool.
 
- @param elementKind       The kind of supplementary veiw.
+ @param elementKind       The kind of supplementary view.
  @param identifier        The identifier of the supplementary view in storyboard.
  @param sectionController The section controller requesting this information.
- @param index             The index of the supplementary vew.
+ @param index             The index of the supplementary view.
 
  @return A supplementary view dequeued from the reuse pool or a newly created one.
  */
@@ -187,11 +187,11 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  Dequeues a supplementary view from the collection view reuse pool.
 
- @param elementKind       The kind of supplementary veiw.
+ @param elementKind       The kind of supplementary view.
  @param sectionController The section controller requesting this information.
  @param nibName           The name of the nib file.
  @param bundle            The bundle in which to search for the nib file. If `nil`, this method searches the main bundle.
- @param index             The index of the supplementary vew.
+ @param index             The index of the supplementary view.
 
  @return A supplementary view dequeued from the reuse pool or a newly created one.
 
@@ -210,7 +210,7 @@ NS_ASSUME_NONNULL_BEGIN
  @param completion        An optional completion block to execute when the updates are finished.
 
  @note This method can be wrapped in `UIView` animation APIs to control the duration or perform without animations. This
- will end up calling `-[UICollectionView performBatchUpdates:completion:] internally, so invalidated changes may not be
+ will end up calling `-[UICollectionView performBatchUpdates:completion:]` internally, so invalidated changes may not be
  reflected in the cells immediately.
  */
 - (void)invalidateLayoutForSectionController:(IGListSectionController<IGListSectionType> *)sectionController

Source/IGListCollectionView.h

@@ -13,8 +13,8 @@
 
 /**
  This class is never actually used by the `IGListKit` infrastructure. 
- It exists only to give compiler errors when editing
- methods are called on the collection view returned by `-[IGListAdapter collectionView]`.
+ It exists only to give compiler errors when editing methods are called on the collection view returned by
+ `-[IGListAdapter collectionView]`.
  */
 IGLK_SUBCLASSING_RESTRICTED
 @interface IGListCollectionView : UICollectionView

Source/IGListCollectionViewLayout.h

@@ -35,7 +35,7 @@ NS_ASSUME_NONNULL_BEGIN
 
  Sections and items are put into the same horizontal row until the max-x position of an item extends beyond the width
  of the collection view. When that happens, the item is "newlined" to the next row. The y position of that row is
- deteremined by the maximum height (including section insets) of the section/item of the previous row.
+ determined by the maximum height (including section insets) of the section/item of the previous row.
 
  Ex. of a section (2,0) with a large width causing a newline.
  ```
@@ -81,9 +81,11 @@ NS_ASSUME_NONNULL_BEGIN
 
 /**
  Create and return a new collection view layout.
- @param stickyHeaders       Set to `YES` to stick section headers to the top of the bounds while scrolling.
- @param topContentInset     The top content inset used to offset the sticky headers. Ignored if stickyHeaders is `NO`.
- @param stretchToEdge       Specifies whether to stretch width of last item to right edge when distance from last item to right edge < epsilon(1)
+
+ @param stickyHeaders   Set to `YES` to stick section headers to the top of the bounds while scrolling.
+ @param topContentInset The top content inset used to offset the sticky headers. Ignored if stickyHeaders is `NO`.
+ @param stretchToEdge   Specifies whether to stretch width of last item to right edge when distance from last item to right edge < epsilon(1)
+
  @return A new collection view layout.
  */
 - (instancetype)initWithStickyHeaders:(BOOL)stickyHeaders

Source/IGListDisplayDelegate.h

@@ -17,7 +17,7 @@
 NS_ASSUME_NONNULL_BEGIN
 
 /**
- Implement this protocol to receive display events for an section controller when it is on screen.
+ Implement this protocol to receive display events for a section controller when it is on screen.
  */
 @protocol IGListDisplayDelegate <NSObject>
 

Source/IGListReloadDataUpdater.h

@@ -14,7 +14,7 @@
 
 /**
  An `IGListReloadDataUpdater` is a concrete type that conforms to `IGListUpdatingDelegate`.
- It is an out-of-box upater for `IGListAdapter` objects to use.
+ It is an out-of-box updater for `IGListAdapter` objects to use.
 
  @note This updater performs simple, synchronous updates using `-[UICollectionView reloadData]`.
  */

Source/IGListScrollDelegate.h

@@ -15,7 +15,7 @@
 @protocol IGListSectionType;
 
 /**
- Implement this protocol to receive display events for an section controller when it is on screen.
+ Implement this protocol to receive display events for a section controller when it is on screen.
  */
 @protocol IGListScrollDelegate <NSObject>
 

Source/IGListSectionType.h

@@ -47,7 +47,7 @@ NS_ASSUME_NONNULL_BEGIN
 
  @return The size for the item at index.
 
- @note The returned size is not garaunteed to be used. The implementation may query sections for their
+ @note The returned size is not guaranteed to be used. The implementation may query sections for their
  layout information at will, or use its own layout metrics. For example, consider a dynamic-text sized list versus a fixed
  height-and-width grid. The former will ask each section for a size, and the latter will likely not.
  */

Source/IGListSingleSectionController.h

@@ -30,7 +30,7 @@ typedef void (^IGListSingleSectionCellConfigureBlock)(id item, __kindof UICollec
  @param item              The model for the section.
  @param collectionContext The collection context for the section.
 
- @return The for the cell.
+ @return The size for the cell.
  */
 typedef CGSize (^IGListSingleSectionCellSizeBlock)(id item, id<IGListCollectionContext> _Nullable collectionContext);
 
@@ -54,7 +54,8 @@ typedef CGSize (^IGListSingleSectionCellSizeBlock)(id item, id<IGListCollectionC
 
 /**
  This section controller is meant to make building simple, single-cell lists easier. By providing the type of cell, a block
- to configure the cell, and a block to return the size of a cell, you can use an IGListAdapter-powered list simpler architecture.
+ to configure the cell, and a block to return the size of a cell, you can use an `IGListAdapter`-powered list with a
+ simpler architecture.
  */
 IGLK_SUBCLASSING_RESTRICTED
 @interface IGListSingleSectionController : IGListSectionController <IGListSectionType>
@@ -79,7 +80,7 @@ IGLK_SUBCLASSING_RESTRICTED
  Creates a new section controller for a given nib name and bundle that will always have only one cell when present in a list.
  
  @param nibName        The name of the nib file for the single cell.
- @param bundle         The bundle in which to search for the nib file. If nil, this method looks for the file in the main bundle.
+ @param bundle         The bundle in which to search for the nib file. If `nil`, this method looks for the file in the main bundle.
  @param configureBlock A block that configures the cell with the item given to the section controller.
  @param sizeBlock      A block that returns the size for the cell given the collection context.
  

Source/IGListStackedSectionController.h

@@ -12,10 +12,10 @@
 #import <IGListKit/IGListMacros.h>
 
 /**
- An instance of `IGListStackedSectionController` is a clustered section controller,
- composed of many child section controllers. It constructs and routes item-level
- indexes to the appropriate child section controller with a local index. This lets you build section controllers made up
- of individual units that can be shared and reused with other section controllers.
+ An instance of `IGListStackedSectionController` is a clustered section controller, composed of many child section
+ controllers. It constructs and routes item-level indexes to the appropriate child section controller with a local
+ index. This lets you build section controllers made up of individual units that can be shared and reused with other
+ section controllers.
 
  For example, you can create a "Comments" section controller that displays lists of text that is used alongside photo,
  video, or slideshow section controllers. You then have four small and manageable section controllers instead of one

Source/Internal/IGListSectionMap.h

@@ -20,7 +20,7 @@ NS_ASSUME_NONNULL_BEGIN
  The IGListSectionMap provides a way to map a collection of objects to a collection of section controllers and achieve
  constant-time lookups O(1).
 
- IGListSectionMap is a mutable object and does not garauntee thread safety.
+ IGListSectionMap is a mutable object and does not guarantee thread safety.
  */
 IGLK_SUBCLASSING_RESTRICTED
 @interface IGListSectionMap : NSObject <NSCopying>