dotnet/fsharp

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The F# compiler, F# core library, F# language service, and F# tooling integration for Visual Studio

Stars: 4.3k
Forks: 876
Open beginner issues: 0
Indexed issues: 1.1k
Avg merge: 4d 11h
Merged PRs (30d): 131

Dominant language: F#
License: MIT
Last GitHub push: Sep 14, 2026
Latest indexed: Sep 15, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted good first issue

Open All

1143 open issues indexed

leftOuterJoin is different from C# version, workaround doesn't work for double left join Open

Area-Queries Feature Improvement

dotnet/fsharp#6552 · 10 comments · 11 reactions · 0 assignees · Indexed Sep 15, 2026
VF# FSI Window improvement for runtime exception display Open

Area-VS-FSI Feature Request

dotnet/fsharp#6592 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Improve Error Reporting: The value or constructor is not defined. Open

Area-Diagnostics Feature Improvement

dotnet/fsharp#6677 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Confusing error message when missing parentheses in let-bound pattern match and tree structure Open

Area-Diagnostics Feature Improvement

dotnet/fsharp#6690 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Suggested fix for calling static base methods is wrong Open

AI-thinks-windows-only Area-LangService-CodeFixes Bug Impact-Low

dotnet/fsharp#6702 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[generics/error message] `?typeid` shown in error message for missing type constraint Open

Bug Impact-Low

dotnet/fsharp#6725 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
F#: [<StructuredFormatDisplay>] in composed records just print dots. (...) Open

Area-Library Feature Improvement

dotnet/fsharp#6753 · 8 comments · 4 reactions · 0 assignees · Indexed Sep 15, 2026
Wrong type inference when using extension method for generic GetEnumerator Open

Area-Compiler-Checking Bug Impact-Medium

dotnet/fsharp#6803 · 4 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Implement IGoToBaseService Open

Area-VS Feature Request

dotnet/fsharp#6818 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Specific indentation of type constraint throws error Open

Feature Request Needs-RFC

dotnet/fsharp#6938 · 5 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
{||} cannot be used as a type Open

Area-Compiler-Checking Bug Impact-Medium

dotnet/fsharp#6941 · 16 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
open FSharp.Core isn't marked as unused Open

Area-LangService-UnusedOpens Feature Improvement

dotnet/fsharp#6975 · 7 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Tail-recursive function calls that have their parameters passed by the pipe operator are not optimized as loops Open

Area-Compiler-Optimization Feature Improvement

dotnet/fsharp#6984 · 10 comments · 3 reactions · 0 assignees · Indexed Sep 15, 2026
Discriminated Unions should come first in pattern matching Intellisense Open

Area-LangService-AutoComplete Feature Request

dotnet/fsharp#6996 · 0 comments · 8 reactions · 0 assignees · Indexed Sep 15, 2026
Struct tuple type alias should give better error message Open

Area-Diagnostics Feature Improvement

dotnet/fsharp#7014 · 3 comments · 5 reactions · 1 assignee · Indexed Sep 15, 2026
Outlining: unfinished statements re-expand collapsed sections Open

AI-thinks-windows-only Area-LangService-AutoComplete Bug Impact-Low

dotnet/fsharp#7078 · 2 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Tooltip icon misplaced Open

Area-LangService-ToolTips Feature Improvement

dotnet/fsharp#7103 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
InternalsVisibleTo + internal module + inline function error message could be improved Open

Area-Diagnostics Feature Improvement

dotnet/fsharp#7110 · 7 comments · 4 reactions · 0 assignees · Indexed Sep 15, 2026
Compiler allows us to box a byreflike type, leading to runtime crash Open

Area-Compiler-Checking Area-Compiler-Checking-Byref Bug Impact-Medium

dotnet/fsharp#7114 · 1 comment · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Accessing C# internal set with public get results in no Property Initialization, and odd setter acce Open

Area-Compiler-Checking Area-Compiler-Checking-Accessibility Feature Improvement

dotnet/fsharp#7165 · 4 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
usage of semicolon in computation expression valid, but not on a single line? Open

Area-Diagnostics Feature Improvement

dotnet/fsharp#7261 · 8 comments · 2 reactions · 1 assignee · Indexed Sep 15, 2026
Intellisense doesn't show property completions next to property initializers Open

Area-LangService-AutoComplete Feature Request

dotnet/fsharp#7275 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Outlining: collapsing the first union case collapses all cases Open

Area-LangService-BlockStructure Feature Improvement

dotnet/fsharp#7278 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Emit diagnostic for ambiguous interface method call Open

Area-Diagnostics Feature Improvement

dotnet/fsharp#7280 · 5 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
No description for FSharpFunc in completion window Open

Area-LangService-AutoComplete Bug Impact-Low

dotnet/fsharp#7375 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Compilation fails depending on runtime path (???) Open

Area-Compiler-SRTP Bug Impact-Medium

dotnet/fsharp#7384 · 6 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Support brace completion after leaving closing bracket character Open

Area-LangService-AutoComplete Feature Request

dotnet/fsharp#7389 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Confusing error message when type stated by qualifying a field Open

Area-Diagnostics Feature Improvement

dotnet/fsharp#7396 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
AutoOpen and RequireQualifiedAccess can both be specified on a module Open

Area-Diagnostics Feature Improvement

dotnet/fsharp#7403 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
RequiresExplicitTypeArguments always results in warnings when applied to functions with no explicit type arguments Open

Area-Diagnostics Feature Improvement

dotnet/fsharp#7415 · 1 comment · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Friend assemblies ("InternalsVisibleTo") can leak via automatic inlining cause runtime error Open

Area-Compiler-Checking Area-Compiler-Checking-Accessibility Area-Compiler-Optimization Bug Impact-Medium

dotnet/fsharp#7422 · 5 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Compiler doesn't accept methods with overloaded nativeptr variants Open

Area-Compiler-Checking Area-Compiler-Checking-Byref Bug Impact-Low

dotnet/fsharp#7428 · 6 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Compiler error FS0193: error : not a nominal type when using an enum from a managed C++ project Open

AI-thinks-windows-only Area-Compiler-ImportAndInterop Bug Impact-Medium

dotnet/fsharp#7448 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Intellisense performance guide for users Open

Feature Request

dotnet/fsharp#7450 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Calling curried static functions of types inside a "namespace rec" raises warning FS0040 Open

Area-Compiler-Checking Area-Compiler-Checking-NameResolution Bug Impact-Medium

dotnet/fsharp#7451 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Send project to interactive for F# is missing Open

Area-VS-FSI Feature Request

dotnet/fsharp#7453 · 0 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Error constructing struct record in member using 'with' Open

Area-Compiler-Checking Area-Compiler-Checking-Byref Bug Impact-Medium

dotnet/fsharp#7536 · 6 comments · 3 reactions · 1 assignee · Indexed Sep 15, 2026
Better warning messages on quotations of "large" disjunctive pattern matches Open

Area-Quotations Bug Impact-Medium

dotnet/fsharp#7589 · 4 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
"Complex" generic constraints from c# interface can't be implemented Open

Area-Compiler-Checking Bug Impact-Medium

dotnet/fsharp#7607 · 1 comment · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Tooltip for module abbreviation shows abbreviated module info only Open

Area-LangService-ToolTips Feature Improvement

dotnet/fsharp#7609 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Allow disabling MRU for completion lists Open

Area-LangService-AutoComplete Feature Request

dotnet/fsharp#7619 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Misleading error message when lambda literals violate equality constraints Open

Area-Diagnostics Feature Improvement

dotnet/fsharp#7637 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Intellisense for record fields not directly visible but can be inferref from parameter Open

Area-LangService-AutoComplete Feature Request

dotnet/fsharp#7664 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
`GetDeclaredItems` returns wrong symbol inside non-recursive declaration Open

Area-LangService-AutoComplete Bug Impact-Medium

dotnet/fsharp#7694 · 5 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Wrong let expression parsing Open

Area-Compiler-Syntax Bug Impact-Medium

dotnet/fsharp#7741 · 9 comments · 1 reaction · 3 assignees · Indexed Sep 15, 2026
Offside rules for accessibility modifier after the '=' in record declarations might need work Open

Area-Compiler-Syntax Feature Improvement

dotnet/fsharp#7747 · 0 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Too many type variables Open

Area-LangService-ToolTips Feature Improvement

dotnet/fsharp#7783 · 8 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Having an @-sign in a let-binding removes the rest of the name, but not in type members Open

Area-Compiler-Checking Bug Impact-Low

dotnet/fsharp#7784 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Recursive type functions subject to repeated evaluation after result is already bound Open

Area-Compiler-Checking Bug Impact-Medium

dotnet/fsharp#7795 · 4 comments · 2 reactions · 1 assignee · Indexed Sep 15, 2026
Wrong confusing warning FS1189 when using SRTP with active patterns Open

Area-Compiler-Syntax Bug Impact-Low

dotnet/fsharp#7797 · 2 comments · 1 reaction · 1 assignee · Indexed Sep 15, 2026

dotnet/fsharp

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