[RFC 1082] - uint type abbreviation (#8185)

* Add uint type abbreviation

* Add uint casting function and test

* Update surface area tests

* update

Author: cartermp

src/fsharp/FSharp.Core/prim-types-prelude.fs

@@ -28,6 +28,7 @@ namespace Microsoft.FSharp.Core
     type bool = System.Boolean
     type decimal = System.Decimal
     type int = int32
+    type uint = uint32
 
     type ``[]``<'T> = (# "!0[]" #)
     type ``[,]``<'T> = (# "!0[0 ...,0 ...]" #)

src/fsharp/FSharp.Core/prim-types-prelude.fsi

@@ -78,6 +78,9 @@ namespace Microsoft.FSharp.Core
     /// <summary>An abbreviation for the CLI type <c>System.Int32</c>.</summary>
     type int = int32
 
+    /// <summary>An abbreviation for the CLI type <c>System.UInt32</c>.</summary>
+    type uint = uint32
+
     /// <summary>Single dimensional, zero-based arrays, written <c>int[]</c>, <c>string[]</c> etc.</summary>
     /// <remarks>Use the values in the <c>Array</c> module to manipulate values 
     /// of this type, or the notation <c>arr.[x]</c> to get/set array

src/fsharp/FSharp.Core/prim-types.fs

@@ -3731,7 +3731,10 @@ namespace Microsoft.FSharp.Core
              when ^T : byte     = (# "conv.i4" value  : int32 #)
 
         [<CompiledName("ToInt")>]
-        let inline int value = int32  value         
+        let inline int value = int32  value
+
+        [<CompiledName("ToUInt")>]
+        let inline uint value = uint32 value
 
         [<CompiledName("ToEnum")>]
         let inline enum< ^T when ^T : enum<int32> > (value:int32) : ^T = EnumOfValue value

src/fsharp/FSharp.Core/prim-types.fsi

@@ -2639,6 +2639,15 @@ namespace Microsoft.FSharp.Core
         [<CompiledName("ToInt")>]
         val inline int        : value:^T -> int        when ^T : (static member op_Explicit : ^T -> int)        and default ^T : int
 
+        /// <summary>Converts the argument to an unsigned 32-bit integer. This is a direct conversion for all 
+        /// primitive numeric types. For strings, the input is converted using <c>UInt32.Parse()</c>  
+        /// with InvariantCulture settings. Otherwise the operation requires an appropriate
+        /// static conversion method on the input type.</summary>
+        /// <param name="value">The input value.</param>
+        /// <returns>The converted int</returns>
+        [<CompiledName("ToUInt")>]
+        val inline uint: value:^T -> uint when ^T: (static member op_Explicit: ^T -> uint) and default ^T: uint
+
         /// <summary>Converts the argument to a particular enum type.</summary>
         /// <param name="value">The input value.</param>
         /// <returns>The converted enum type.</returns>

tests/fsharp/Compiler/Language/UIntTests.fs

@@ -0,0 +1,10 @@
+namespace FSharp.Compiler.UnitTests
+
+open NUnit.Framework
+
+[<TestFixture>]
+module UIntTests =
+    let ``uint type abbreviation works`` () =
+        let src = "let x = uint 12"
+        let expectedErrors = [||]
+        CompilerAssert.TypeCheckWithErrors src expectedErrors