Add Extract to function and Extract to private member refactorings

docs/release-notes/.VisualStudio/18.vNext.md

@@ -1,6 +1,8 @@
 ### Added
 
+* **Extract to let binding** and **Extract to literal** refactorings for a selected expression. The value is bound in front of the statement that uses it, so it is computed before the code that preceded the selection in that statement; a constant in a module-level declaration becomes a `[<Literal>]` in front of that declaration, also with just the caret inside the constant. ([PR #20537](https://github.com/dotnet/fsharp/pull/20537))
 * Code-fixes for FS3888 (compiler-semantic attribute on the `.fs` but not the `.fsi`): copy the attribute into the `.fsi`, or remove it from the `.fs`. ([Issue #19560](https://github.com/dotnet/fsharp/issues/19560), [PR #19880](https://github.com/dotnet/fsharp/pull/19880))
+* **Extract to local function**, **Extract to module function** and **Extract to private member** refactorings for a selected expression. Values the selection reads from the enclosing function, member or lambda become parameters in the order they are first used, typed as the new **Parameter types in Extract to function** option under **Code Fixes** asks. A selection that assigns to a captured mutable local, or reads a byref or byref-like value from outside, is not offered. ([Issue #14449](https://github.com/dotnet/fsharp/issues/14449), [PR #20538](https://github.com/dotnet/fsharp/pull/20538))
 * Expand `<inheritdoc/>` in IDE tooltips, completion, and signature help, inheriting XML documentation from base classes, interfaces, overridden members, and constructors. ([Issue #19175](https://github.com/dotnet/fsharp/issues/19175), [PR #19188](https://github.com/dotnet/fsharp/pull/19188))
 
 ### Fixed

vsintegration/src/FSharp.Editor/FSharp.Editor.fsproj

@@ -101,10 +101,13 @@
     <Compile Include="Commands\HelpContextService.fs" />
     <Compile Include="Commands\FsiCommandService.fs" />
     <Compile Include="Commands\XmlDocCommandService.fs" />
+    <Compile Include="Refactor\RefactoringHelpers.fs" />
     <Compile Include="Refactor\AddReturnType.fs" />
     <Compile Include="Refactor\ChangeTypeofWithNameToNameofExpression.fs" />
     <Compile Include="Refactor\AddExplicitTypeToParameter.fs" />
     <Compile Include="Refactor\ChangeDerefToValueRefactoring.fs" />
+    <Compile Include="Refactor\ExtractLetBinding.fs" />
+    <Compile Include="Refactor\ExtractFunction.fs" />
     <Compile Include="CodeFixes\IFSharpCodeFix.fs" />
     <Compile Include="CodeFixes\CodeFixHelpers.fs" />
     <Compile Include="CodeFixes\ChangeEqualsInFieldTypeToColon.fs" />

vsintegration/src/FSharp.Editor/FSharp.Editor.resx

@@ -368,4 +368,19 @@ Use live (unsaved) buffers for analysis</value>
   <data name="ReturnsHeader" xml:space="preserve">
     <value>Returns:</value>
   </data>
+  <data name="ExtractToLetBinding" xml:space="preserve">
+    <value>Extract to let binding</value>
+  </data>
+  <data name="ExtractToLiteral" xml:space="preserve">
+    <value>Extract to literal</value>
+  </data>
+  <data name="ExtractToLocalFunction" xml:space="preserve">
+    <value>Extract to local function</value>
+  </data>
+  <data name="ExtractToModuleFunction" xml:space="preserve">
+    <value>Extract to module function</value>
+  </data>
+  <data name="ExtractToPrivateMember" xml:space="preserve">
+    <value>Extract to private member</value>
+  </data>
 </root>

vsintegration/src/FSharp.Editor/Options/EditorOptions.fs

@@ -16,6 +16,12 @@ type EnterKeySetting =
     | NewlineOnCompleteWord
     | AlwaysNewline
 
+[<RequireQualifiedAccess>]
+type ParameterAnnotationSetting =
+    | Always
+    | WhenNeeded
+    | Never
+
 // CLIMutable to make the record work also as a view model
 [<CLIMutable>]
 type IntelliSenseOptions =
@@ -68,6 +74,7 @@ type CodeFixesOptions =
         UnusedDeclarations: bool
         SuggestNamesForErrors: bool
         RemoveParens: bool
+        ExtractFunctionParameterAnnotations: ParameterAnnotationSetting
     }
 
     static member Default =
@@ -79,6 +86,7 @@ type CodeFixesOptions =
             UnusedDeclarations = true
             SuggestNamesForErrors = true
             RemoveParens = false
+            ExtractFunctionParameterAnnotations = ParameterAnnotationSetting.Always
         }
 
 [<CLIMutable>]
@@ -213,7 +221,14 @@ module internal OptionsUI =
     [<Guid(Guids.codeFixesOptionPageIdString)>]
     type internal CodeFixesOptionPage() =
         inherit AbstractOptionPage<CodeFixesOptions>()
-        override this.CreateView() = upcast CodeFixesOptionControl()
+
+        override this.CreateView() =
+            let view = CodeFixesOptionControl()
+            let path = nameof CodeFixesOptions.Default.ExtractFunctionParameterAnnotations
+            bindRadioButton view.annotateAlways path ParameterAnnotationSetting.Always
+            bindRadioButton view.annotateWhenNeeded path ParameterAnnotationSetting.WhenNeeded
+            bindRadioButton view.annotateNever path ParameterAnnotationSetting.Never
+            upcast view
 
     [<Guid(Guids.languageServicePerformanceOptionPageIdString)>]
     type internal LanguageServicePerformanceOptionPage() =
@@ -263,6 +278,9 @@ module EditorOptionsExtensions =
 
         member this.IsFsharpRemoveParensEnabled = this.EditorOptions.CodeFixes.RemoveParens
 
+        member this.FSharpExtractFunctionParameterAnnotations =
+            this.EditorOptions.CodeFixes.ExtractFunctionParameterAnnotations
+
         member this.IsFSharpCodeFixesSuggestNamesForErrorsEnabled =
             this.EditorOptions.CodeFixes.SuggestNamesForErrors