Breaking Change: Fix argument name in CompareInfo.IsPrefix (suffix -> prefix)

[jeffhandley]

Fix argument name in CompareInfo.IsPrefix (suffix -> prefix)

This CompareInfo.IsPrefix() API was added in .NET 5.0 RC1, but there is a mistake in the argument name where suffix was used instead of prefix. The implementation is correct, but the reference assembly was wrong. dotnet/runtime#41803 fixed the argument name. This fix will ship with .NET 5.0 RC2.

Version introduced

.NET 5.0 RC2

Old behavior

The previous method signature was the following, with an argument named suffix.

public bool IsPrefix(System.ReadOnlySpan<char> source, System.ReadOnlySpan<char> suffix, System.Globalization.CompareOptions options, out int matchLength)

New behavior

The updated method signature is the following, with the argument renamed to prefix.

public bool IsPrefix(System.ReadOnlySpan<char> source, System.ReadOnlySpan<char> prefix, System.Globalization.CompareOptions options, out int matchLength)

Reason for change

This corrects a mistake in the argument name and will improve the API, avoiding confusion by users.

Recommended action

If the argument was being used as a named argument, update calling code to correct the argument name to match the renamed prefix name.

Category

• ASP.NET Core
• C#
• Code analysis
• Core .NET libraries
• Cryptography
• Data
• Debugger
• Deployment
• Globalization
• Interop
• JIT
• LINQ
• Managed Extensibility Framework (MEF)
• MSBuild
• Networking
• Printing
• Security
• Serialization
• Visual Basic
• Windows Forms
• Windows Presentation Foundation (WPF)
• XML, XSLT

Affected APIs

CompareInfo.IsPrefix(ReadOnlySpan<char>, ReadOnlySpan<char>, CompareOptions, out int)

The affected overload was added in .NET 5.0 RC1 and was not yet present in documentation at the time of this breaking change in RC2.

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Issue metadata

• Issue type: breaking-change

[jeffhandley]

Updated the description to reflect that the breaking change was introduced in 5.0 RC2.