C# Language Design Notes for 2020

Overview of meetings and agendas for 2020

Dec 16, 2020

C# Language Design Notes for December 16th, 2020

• List patterns
• Definite assignment changes

Dec 14, 2020

C# Language Design Notes for December 14th, 2020

• List patterns

Dec 7, 2020

C# Language Design Notes for December 7th, 2020

• Required Properties

Dec 2, 2020

C# Language Design Notes for December 2nd, 2020

• Partner scenarios in roles and extensions

Nov 16, 2020

C# Language Design Notes for November 16th, 2020

• Triage

Nov 11, 2020

C# Language Design Notes for November 11th, 2020

• IsRecord in metadata
• Triage

Nov 4, 2020

C# Language Design Notes for November 4th, 2020

• Nullable parameter defaults
• Argument state after call for AllowNull parameters

Oct 26, 2020

C# Language Design Notes for October 26st, 2020

• Pointer types in records
• Triage

Oct 21, 2020

C# Language Design Notes for October 21st, 2020

• Primary Constructors
• Direct Parameter Constructors

Oct 14, 2020

C# Language Design Notes for October 14th, 2020

• Triage
• Milestone Simplification

Oct 12, 2020

C# Language Design Notes for October 12th, 2020

• General improvements to the struct experience (continued)

Oct 7, 2020

C# Language Design Notes for October 7th, 2020

• record struct syntax
• data members redux
• ReadOnlySpan<char> patterns

Oct 5, 2020

C# Language Design Notes for October 5th, 2020

• record struct primary constructor defaults
• Changing the member type of a primary constructor parameter
• data members

Sep 30, 2020

C# Language Design Notes for September 30th, 2020

• record structs
  • struct equality
  • with expressions
  • Primary constructors and data properties

Sep 28, 2020

C# Language Design Notes for September 28th, 2020

• Warning on double.NaN
• Triage

Sep 23, 2020

C# Language Design Notes for September 23rd, 2020

• General improvements to the struct experience

Sep 16, 2020

C# Language Design Notes for September 16th, 2020

• Required Properties
• Triage

Sep 14, 2020

C# Language Design Notes for September 14th, 2020

• Partial method signature matching
• Null-conditional handling of the nullable suppression operator
• Annotating IEnumerable.Cast
• Nullability warnings in user-written record code
• Tuple deconstruction mixed assignment and declaration

Sep 9, 2020

C# Language Design Notes for September 9th, 2020

• Triage issues still in C# 9.0 candidate
• Triage issues in C# 10.0 candidate

Aug 24, 2020

C# Language Design Notes for August 24th, 2020

• Warnings on types named record
• base calls on parameterless records
• Omitting unnecessary synthesized record members
• record ToString behavior review
  • Behavior of trailing commas
  • Handling stack overflows
  • Should we omit the implementation of ToString on abstract records
  • Should we call ToString prior to StringBuilder.Append on value types
  • Should we try and avoid the double-space in an empty record
  • Should we try and make the typename header print more economic
• Reference equality short circuiting

Jul 27, 2020

C# Language Design Notes for July 27th, 2020

• Improved nullable analysis in constructors (Rikki)
• Equality operators (== and !=) in records (Fred)
• .ToString() or GetDebuggerDisplay() on records? (Julien)
• Restore W-warning to T t = default; for generic T, now you can write T?? (Julien)

Jul 20, 2020

C# Language Design Notes for July 20th, 2020

• struct private fields in definite assignment (Neal/Julien)
  • Proposal 1
  • Proposal 2
• Finish Triage
• Records-related features to pick up in the next version of C# (Mads)

Jul 13, 2020

C# Language Design Notes for July 13th, 2020

• Triage open issues

Jul 6, 2020

C# Language Design Notes for July 6, 2020

• Repeat Attributes in Partial Members (Rikki)
• sealed on data members
• Required properties (Fred)

Jul 1, 2020

C# Language Design Notes for July 1, 2020

• Non-defaultable struct types (Sam, Chuck)
• Confirm unspeakable Clone method and long-term implications (Jared/Julien)

Jun 29, 2020

C# Language Design Notes for June 29, 2020

• Static interface members (Miguel, Aaron, Mads, Carol)

Jun 24, 2020

C# Language Design Notes for June 24, 2020

• Parameter null checking: finalize syntax
• https://github.com/dotnet/csharplang/issues/3275 Variance on static interface members (Aleksey)
• Function pointer question (Fred)

Jun 22, 2020

C# Language Design Notes for June 22, 2020

1. Data properties

2. Clarifying what's supported in records for C# 9

   • Structs

   • Inheritance with records and classes

Jun 17, 2020

C# Language Design Notes for June 17, 2020

1. Null-suppression & null-conditional operator
2. parameter! syntax
3. T??

Jun 15, 2020

C# Language Design Notes for June 15, 2020

Record:

1. modreq for init accessors

2. Initializing readonly fields in same type

3. init methods

4. Equality dispatch

5. Confirming some previous design decisions

6. IEnumerable.Current

Jun 10, 2020

C# Language Design Notes for June 10, 2020

• https://github.com/dotnet/csharplang/issues/1711 Roles and extensions

Jun 1, 2020

C# Language Design Notes for June 1, 2020

Records: 1. Base call syntax 2. Synthesizing positional record members and assignments 3. Record equality through inheritance

May 27, 2020

C# Language Design Notes for May 27, 2020

Record syntax 1. Record structs? 2. Record syntax/keyword 3. Details on property shorthand syntax

May 11, 2020

C# Language Design Notes for May 11, 2020

Records

May 6, 2020

C# Language Design Notes for May 6, 2020

1. Target-typing ?: when the natural type isn't convertible to the target type.
2. Allow if (x is not string y) pattern.
3. Open issues in extension GetEnumerator
4. Args in top-level programs

May 4, 2020

C# Language Design Notes for May 4, 2020

1. Reviewing design review feedback

April 27, 2020

C# Language Design Notes for April 27, 2020

Records: positional & primary constructors

April 20, 2020

C# Language Design Notes for April 20, 2020

Records: Factories

April 15, 2020

C# Language Design Notes for April 15, 2020

1. Non-void and non-private partial methods
2. Top-level programs

April 13. 2020

C# Language Design Notes for April 13, 2020

1. Roadmap for records
2. Init-only properties

April 8, 2020

C# Language Design Notes for April 8, 2020

1. e is dynamic pure null check
2. Target typing ?:
3. Inferred type of an or pattern
4. Module initializers

April 6, 2020

C# Language Design Notes for April 6, 2020

1. Record Monday: Init-only members

April 1, 2020

C# Language Design Notes for April 1, 2020

1. Function pointer design adjustments

2. field keyword in properties

March 30, 2020

1. Record Monday

C# Language Design Notes for March 30, 2020

March 25, 2020

C# Language Design Notes for March 25, 2020

1. Open issues with native int

2. Open issues with target-typed new

March 23, 2020

C# Language Design Notes for March 23, 2020

1. Triage
2. Builder-based records

March 9, 2020

C# Language Design Notes for March 9, 2020

1. Simple programs

2. Records

Feb 26, 2020

C# Language Design Notes for Feb. 26, 2020

Design Review

Feb 24

C# Language Design Notes for Feb. 24, 2020

Taking another look at "nominal" records

Feb 19

C# Language Design Notes for Feb. 19, 2020

State-based value equality

Feb 12

C# Language Design Notes for Feb. 12, 2020

Records

Feb 10

C# Language Design Notes for Feb. 10, 2020

Records

Feb 5

C# Language Design Notes for Feb. 5, 2020

• Nullability of dependent calls (Chuck, Julien)
• https://github.com/dotnet/csharplang/issues/3137 Records as individual features (Mads)

Feb 3

C# Language Design Notes for Feb. 3, 2020

Value Equality

Jan 29, 2020

C# Language Design Notes for Jan. 29, 2020

Records: "With-ers"

Jan 22, 2020

C# Language Design Notes for Jan 22, 2020

1. Top-level statements and functions
2. Expression Blocks

Jan 15, 2020

C# Language Design Notes for Jan 15, 2020

Records

1. "programming with data"
2. Decomposing subfeatures of records

Jan 8, 2020

C# Language Design Notes for Jan 8, 2020

1. Unconstrained type parameter annotation
2. Covariant returns

Jan 6, 2020

C# Language Design Notes for Jan 6, 2020

1. Use attribute info inside method bodies
2. Making Task-like types covariant for nullability
3. Casting to non-nullable reference type
4. Triage