csharplang/meetings/2019

Upcoming meetings for 2019

Schedule ASAP

Schedule when convenient

• removing support for #pragma warning enable (https://github.com/dotnet/roslyn/issues/36550) (Julien)
• disallow expr!! and use parameter!! (instead of parameter!) (Mads)
• allow #nullable to mean #nullable enable (Julien)
• effect of [DoesNotReturn] on various flow analyses? (https://github.com/dotnet/roslyn/issues/37081) (Julien)
• suppressing LHS of compound assignment (https://github.com/dotnet/roslyn/issues/36617) (Julien)
• warn on [NonNull] and other attributes outside of nullable context (https://github.com/dotnet/roslyn/issues/36588) (Julien)
• confirm suppression on ref arguments (https://github.com/dotnet/roslyn/issues/35555) (Julien)
• confirm features that are pushed out:
  • nullable attributes do not affect method bodies ([AllowNull] T M() { return default; })
  • nullable attributes not checked in OHI
  • no diagnostics on misused nullable attributes
• async LINQ (Julien)
• Syntax of positional records/primary constructors (Andy)
• Discussion of refreshing language spec (Neal)
• Conceptual model for tuples (Mads, Neal)
• Close on flag for warning waves (existing /warn or new /warnVersion?)

Recurring topics

• Triage championed features
• Triage milestones
• Design review

Sep 25, 2019

Sep 18, 2019

Sep 16, 2019

Sep 11, 2019

• Close https://github.com/dotnet/roslyn/issues/37313 (Rikki, Phillip)
• Triage new proposed 9.0 features
• Finish triaging away 8.X milestone

Sep 4, 2019

• https://github.com/dotnet/roslyn/issues/37313 (Rikki, Phillip)

Aug 28, 2019

• Triage language features

Aug 26, 2019

• Triage language features

May 22, 2019

• Confirm whether we want abstract modifier to be implied for interface implementations inside derived interfaces unless there is an implementation.

May 1, 2019

• Nullable attributes - continue discussion
• Nullable opt-in - do we need to adjust the story?

C# Language Design Notes for 2019

Overview of meetings and agendas for 2019

Jul 22, 2019

C# Language Design Notes for July 22, 2019

1. Discuss the new records proposal

Jul 17, 2019

C# Language Design Notes for July 17, 2019

1. Nullability of events

2. Triage, see https://github.com/dotnet/csharplang/projects/4

   • Triage championed features https://github.com/dotnet/csharplang/projects/4#column-4649189
   • Triage milestones

Jul 10, 2019

C# Language Design Notes for July 10, 2019

1. Empty switch statement
2. [DoesNotReturn] attribute
3. Revisiting the param! null-checking feature

May 15, 2019

C# Language Design Notes for May 15, 2019

• Close on nullable attributes (Mads and Steve)

May 13, 2019

C# Language Design Notes for May 13, 2019

• Close on desired rules for warning suppressions and #nullable interacting

Apr 29, 2019

C# Language Design Notes for Apr 29, 2019

1. Default interface implementations and base() calls
2. Async iterator cancellation
3. Attributes on local functions

Apr 24, 2019

C# Language Design Notes for Apr 24, 2019

MaybeNull and related nullable reference type attributes

Apr 22, 2019

C# Language Design Notes for Apr 22, 2019

1. Inferred nullable state from a finally block
2. Implied constraint for a type parameter of a partial?
3. Target-typed switch expression
4. DefaultCancellationAttribute and overriding/hiding/interface implementation

Apr 15, 2019

C# Language Design Notes for Apr 15, 2019

1. CancellationToken in iterators
2. Implied nullable constraints in nullable disabled code
3. Inheriting constraints in nullable disabled code
4. Declarations with constraints declared in #nullable disabled code
5. Result type of ??= expression
6. Use annotation context to compute the annotations?
7. Follow-up decisions for pattern-based Index/Range

Apr 3, 2019

C# Language Design Notes for Apr 3, 2019

1. Ambiguous implementations/overrides with generic methods and NRTs
2. NRT and dynamic

Apr 1, 2019

C# Language Design Notes for Apr 1, 2019

1. Pattern-based Index/Range translation

2. Default interface implementations: Is object.MemberwiseClone() accessible in an interface?

Mar 27, 2019

C# Language Design Notes for Mar 27, 2019

1. Switch expression syntax

2. Default interface implementations

   1. Reabstraction

   2. Explicit interface abstract overrides in classes

   3. object.MemberwiseClone()

   4. static int P {get; set} semantics

   5. partial on interface methods

3. ? on unconstrained generic param T

Mar 25, 2019

C# Design Review Notes for Mar 25, 2019

We brought in the design review team to look at some of our recent and open decisions in C# LDM.

1. Nullable reference types: shipping annotations
2. Pattern-based indexing with Index and Range
3. Cancellation tokens in async streams

Mar 19, 2019

C# Language Design Notes for March 19, 2019

We held a live LDM during the MVP summit with some Q&A about C# 8 and the future

Topics:

1. Records
2. "Extension interfaces"/roles
3. Macros
4. IAsyncEnumerable
5. "Partially automatic" properties
6. More integration with reactive extensions

Mar 13, 2019

C# Language Design Notes for March 13, 2019

1. Interface "reabstraction" with default interface implementations
2. Precedence of the switch expression
3. or keyword in patterns
4. "Pure" null tests and the switch statement/expression

Mar 6, 2019

C# Language Design Notes for March 6th, 2019

1. Pure checks in the switch expression
2. Nullable analysis of unreachable code
3. Warnings about nullability on expressions with errors
4. Handling of type parameters that cannot be annotated
5. Should anonymous type fields have top-level nullability?
6. Element-wise analysis of tuple conversions

Mar 4, 2019

C# Language Design Notes for March 4, 2019

1. Nullable user studies
2. Interpolated string and string.Format optimizations

Feb 27, 2019

C# Language Design Notes for Feb 27, 2019

1. Allow ObsoleteAttribute on property accessors
2. More Default Interface Member questions

Feb 25, 2019

C# Language Design Notes for Feb 25, 2019

• Open issues in default interface methods (https://github.com/dotnet/csharplang/issues/406).
  • Base calls
  • We currently have open issues around protected, internal, reabstraction, and static fields among others.

Feb 20, 2019

C# Language Design Notes for Feb 20, 2019

• Nullable Reference Types: Open LDM Issues https://github.com/dotnet/csharplang/issues/2201

Feb 13, 2019

C# Language Design Notes for Feb 13, 2019

• Nullable Reference Types: Open LDM Issues https://github.com/dotnet/csharplang/issues/2201

Jan 23, 2019

C# Language Design Notes for Jan 23, 2019

Function pointers (Updated proposal)

Jan 16, 2019

C# Language Design Notes for Jan 16, 2019

1. Shadowing in lambdas
2. Pattern-based disposal in await foreach

Jan 14, 2019

C# Language Design Notes for Jan 14, 2019

• Generating null-check for parameter! https://github.com/dotnet/csharplang/pull/2144

Jan 9, 2019

C# Language Design Notes for Jan 9, 2019

1. GetAsyncEnumerator signature
2. Ambiguities in nullable array type syntax
3. Recursive Patterns Open Language Issues https://github.com/dotnet/csharplang/issues/2095

Jan 7, 2019

C# Language Design Notes for Jan 7, 2019

Nullable:

1. Variance in overriding/interface implementation
2. Breaking change in parsing array specifiers