add requireSomeWith doc

Author: joprice

gitbook/result/requireFunctions.md

@@ -64,9 +64,9 @@ let result : Result<unit, string> =
 // Error "Value must be false"
 ```
 
-## requireSome
+## requireSomeWith
 
-Converts an Option to a Result, using the given error if None.
+Converts an Option to a Result, using the given function to supply an error if None.
 
 ### Function Signature
 
@@ -81,7 +81,7 @@ Converts an Option to a Result, using the given error if None.
 ```fsharp
 let result : Result<unit, string> =
     Some 1
-    |> Result.requireSome "Value must be Some"
+    |> Result.requireSomeWith (fun () -> "Value must be Some")
     
 // Ok ()
 ```
@@ -91,7 +91,7 @@ let result : Result<unit, string> =
 ```fsharp
 let result : Result<unit, string> =
     None
-    |> Result.requireSome "Value must be Some"
+    |> Result.requireSomeWith (fun () -> "Value must be Some")
     
 // Error "Value must be Some"
 ```

src/FsToolkit.ErrorHandling/Result.fs

@@ -307,6 +307,14 @@ module Result =
         | Some x -> Ok x
         | None -> Error error
 
+    /// <summary>
+    /// Returns the contained value if <c>Some</c>, otherwise evaluates <param name="ifErrorThunk"/> and returns the value.
+    ///
+    /// Documentation is found here: <href>https://demystifyfp.gitbook.io/fstoolkit-errorhandling/fstoolkit.errorhandling/result/others#requireSomeWith</href>
+    /// </summary>
+    /// <param name="ifErrorThunk">The function to evaluate if the result is <c>Error</c>.</param>
+    /// <param name="option">The input result.</param>
+    /// <returns>The contained value if <c>Some</c>, otherwise the result of evaluating <paramref name="ifErrorThunk"/>.</returns>
     let inline requireSomeWith
         (ifErrorThunk: unit -> 'error)
         (option: 'ok option)