Add new shared SelectXXXAsArray helpers #11796
Open
+1,602
−56
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Add helpers that combine Select And Order/OrderBy/OrderDescending/OrderByDescending to avoid a common LINQ anti-pattern: ```C# List<int> list = [1, 2, 3, 4, 5]; var result = list.Select(x => x * 2).OrderDescendingAsArray(); ``` The code above results in extra allocations by the LINQ Select(...) method, even though the expected results in an ImmutableArray<int>. With these helpers in place, the code above can be written more efficiently as: ```C# List<int> list = [1, 2, 3, 4, 5]; var result = list.SelectAndOrderDescendingAsArray(x => x * 2); ```
LINQ provides a Select(...) overload where the selector takes an int representing the item index. This change adds a similar overload for SelectAsArray.
davidwengier
approved these changes
Apr 28, 2025
src/Shared/Microsoft.AspNetCore.Razor.Utilities.Shared/EnumerableExtensions.cs
Outdated
Show resolved
Hide resolved
src/Shared/Microsoft.AspNetCore.Razor.Utilities.Shared/EnumerableExtensions.cs
Outdated
Show resolved
Hide resolved
Use TryGetCount(...) to retrieve a capacity up front before creating a PooledArrayBuilder<T>.
The type tests for ImmutableArray<T> and IReadOnlyList<T> aren't needed in SelectAndOrderXXXAsArray helpers, since those tests are already performed by their calls to SelectAsArray.
ryzngard
approved these changes
Apr 29, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This adds a handful of new SelectXXXAsArray extension methods and overloads. In particular, there are new
SelectAndOrderXXXAsArraymethods that transform elements and order them in a single pass.