- Speed up
for x in xs -> …in list & array comprehensions in certain scenarios. (PR #16948) - Lower integral ranges to fast loops in more cases and optimize list and array construction from ranges. (PR #16650, PR #16832)
- Support for nullable reference types (PR #15181)
- Bidirectional F#/C# interop for 'unmanaged' constraint. (PR #12154)
- Make
.Is*discriminated union properties visible. (Language suggestion #222, PR #16341) - Allow returning bool instead of unit option for partial active patterns. (Language suggestion #1041, PR #16473)
- Allow access modifies to auto properties getters and setters (Language suggestion #430, PR 16687, PR 16861, PR 17522)
- Allow #nowarn to support the FS prefix on error codes to disable warnings (Issue #17206, PR #17209)
- Allow ParsedHashDirectives to have argument types other than strings (Issue #17240, PR #17209)
- Support empty-bodied computation expressions. (Language suggestion #1232, PR #17352)
- Allow object expression without overrides. (Language suggestion #632, PR #17387)
- Enable FSharp 9.0 Language Version (Issue #17497), PR))
- Allow extension methods without type attribute work for types from imported assemblies. (PR #16368)
- Enforce AttributeTargets on let values and functions. (PR #16692)
- Enforce AttributeTargets on union case declarations. (PR #16764)
- Enforce AttributeTargets on implicit constructors. (PR #16845)
- Enforce AttributeTargets on structs and classes (PR #16790)
- Ensure consistent interaction between ``#line
and#nowarn` directives (PR #17649)
- Lower interpolated strings to string concatenation. (PR #16556)