Improve iterator traits for foundation types

Author: madsmtm

objc2-foundation/CHANGELOG.md

@@ -8,6 +8,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Added
 * Implement `UnwindSafe` and `RefUnwindSafe` for all objects.
+* Implemented `IntoIterator` for references to `NSArray`, `NSMutableArray`,
+  `NSData` and `NSMutableData`.
+* Implemented `Extend` for `NSMutableArray`.
+* Add extra `Extend<&u8>` impl for `NSMutableData`.
 
 ### Fixed
 * Made `Debug` impls for all objects print something useful.

objc2-foundation/src/array.rs

@@ -1,7 +1,7 @@
 use alloc::vec::Vec;
 use core::fmt;
 use core::marker::PhantomData;
-use core::ops::{Index, Range};
+use core::ops::{Index, IndexMut, Range};
 use core::panic::{RefUnwindSafe, UnwindSafe};
 
 use objc2::rc::{DefaultId, Id, Owned, Ownership, Shared, SliceId};
@@ -10,8 +10,8 @@ use objc2::Message;
 use objc2::{msg_send, msg_send_id};
 
 use crate::{
-    NSCopying, NSEnumerator, NSFastEnumeration, NSMutableArray, NSMutableCopying, NSObject,
-    NSRange, __inner_extern_class,
+    NSCopying, NSEnumerator, NSFastEnumeration, NSFastEnumerator, NSMutableArray, NSMutableCopying,
+    NSObject, NSRange, __inner_extern_class,
 };
 
 __inner_extern_class! {
@@ -199,6 +199,15 @@ unsafe impl<T: Message, O: Ownership> NSFastEnumeration for NSArray<T, O> {
     type Item = T;
 }
 
+impl<'a, T: Message, O: Ownership> IntoIterator for &'a NSArray<T, O> {
+    type Item = &'a T;
+    type IntoIter = NSFastEnumerator<'a, NSArray<T, O>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter_fast()
+    }
+}
+
 impl<T: Message, O: Ownership> Index<usize> for NSArray<T, O> {
     type Output = T;
 
@@ -207,6 +216,12 @@ impl<T: Message, O: Ownership> Index<usize> for NSArray<T, O> {
     }
 }
 
+impl<T: Message> IndexMut<usize> for NSArray<T, Owned> {
+    fn index_mut(&mut self, index: usize) -> &mut T {
+        self.get_mut(index).unwrap()
+    }
+}
+
 impl<T: Message> DefaultId for NSArray<T, Shared> {
     type Ownership = Shared;
 

objc2-foundation/src/data.rs

@@ -129,6 +129,15 @@ impl fmt::Debug for NSData {
     }
 }
 
+impl<'a> IntoIterator for &'a NSData {
+    type Item = &'a u8;
+    type IntoIter = core::slice::Iter<'a, u8>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.bytes().iter()
+    }
+}
+
 pub(crate) unsafe fn data_with_bytes(cls: &Class, bytes: &[u8]) -> *mut Object {
     let bytes_ptr: *const c_void = bytes.as_ptr().cast();
     unsafe {

objc2-foundation/src/mutable_array.rs

@@ -11,8 +11,8 @@ use objc2::{msg_send, msg_send_id};
 
 use crate::array::from_refs;
 use crate::{
-    NSArray, NSComparisonResult, NSCopying, NSFastEnumeration, NSMutableCopying, NSObject,
-    __inner_extern_class,
+    NSArray, NSComparisonResult, NSCopying, NSFastEnumeration, NSFastEnumerator, NSMutableCopying,
+    NSObject, __inner_extern_class,
 };
 
 __inner_extern_class! {
@@ -175,6 +175,22 @@ unsafe impl<T: Message, O: Ownership> NSFastEnumeration for NSMutableArray<T, O>
     type Item = T;
 }
 
+impl<'a, T: Message, O: Ownership> IntoIterator for &'a NSMutableArray<T, O> {
+    type Item = &'a T;
+    type IntoIter = NSFastEnumerator<'a, NSMutableArray<T, O>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter_fast()
+    }
+}
+
+impl<T: Message, O: Ownership> Extend<Id<T, O>> for NSMutableArray<T, O> {
+    fn extend<I: IntoIterator<Item = Id<T, O>>>(&mut self, iter: I) {
+        let iterator = iter.into_iter();
+        iterator.for_each(move |item| self.push(item));
+    }
+}
+
 impl<T: Message, O: Ownership> Index<usize> for NSMutableArray<T, O> {
     type Output = T;
 

objc2-foundation/src/mutable_data.rs

@@ -178,9 +178,16 @@ impl Extend<u8> for NSMutableData {
     ///
     /// [`extend_from_slice`]: Self::extend_from_slice
     fn extend<T: IntoIterator<Item = u8>>(&mut self, iter: T) {
-        for item in iter {
-            self.push(item);
-        }
+        let iterator = iter.into_iter();
+        iterator.for_each(move |item| self.push(item));
+    }
+}
+
+// Vec also has this impl
+impl<'a> Extend<&'a u8> for NSMutableData {
+    fn extend<T: IntoIterator<Item = &'a u8>>(&mut self, iter: T) {
+        let iterator = iter.into_iter();
+        iterator.for_each(move |item| self.push(*item));
     }
 }
 
@@ -216,6 +223,24 @@ impl fmt::Debug for NSMutableData {
     }
 }
 
+impl<'a> IntoIterator for &'a NSMutableData {
+    type Item = &'a u8;
+    type IntoIter = core::slice::Iter<'a, u8>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.bytes().iter()
+    }
+}
+
+impl<'a> IntoIterator for &'a mut NSMutableData {
+    type Item = &'a mut u8;
+    type IntoIter = core::slice::IterMut<'a, u8>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.bytes_mut().iter_mut()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use objc2::runtime::Object;
@@ -287,6 +312,8 @@ mod tests {
         let mut data = NSMutableData::with_bytes(&[1, 2]);
         data.extend(3..=5);
         assert_eq!(data.bytes(), &[1, 2, 3, 4, 5]);
+        data.extend(&*NSData::with_bytes(&[6, 7]));
+        assert_eq!(data.bytes(), &[1, 2, 3, 4, 5, 6, 7]);
     }
 
     #[test]

objc2/src/rc/id_forwarding_impls.rs

@@ -160,6 +160,19 @@ impl<I: ExactSizeIterator + ?Sized> ExactSizeIterator for Id<I, Owned> {
 
 impl<I: FusedIterator + ?Sized> FusedIterator for Id<I, Owned> {}
 
+// TODO: Consider this impl
+// impl<'a, T, O: Ownership> IntoIterator for &'a Id<T, O>
+// where
+//     &'a T: IntoIterator,
+// {
+//     type Item = <&'a T as IntoIterator>::Item;
+//     type IntoIter = <&'a T as IntoIterator>::IntoIter;
+//
+//     fn into_iter(self) -> Self::IntoIter {
+//         (**self).into_iter()
+//     }
+// }
+
 impl<T, O: Ownership> borrow::Borrow<T> for Id<T, O> {
     fn borrow(&self) -> &T {
         Deref::deref(self)