Question

Is there a language, which is:

1) functional

2) has type inference

3) has currying

4) and has types as first-class values

also would like to compile from it to JVM and/or CLR

Answer 1

F# is functional and has type inference, currying and types as first-class values in the sense that you can dissect types at run-time via reflection. It compiles to the CLR and works well on Mono.

EXAMPLE: Taken from my (non-free) article Structural Typing in the F#.NET Journal:

The following createType function creates a new .NET assembly, new module and new public class type of the given name:

> let createType typeName =
    let name = System.Reflection.AssemblyName(Name="tmpAssembly")
    let run = System.Reflection.Emit.AssemblyBuilderAccess.Run
    let builder = System.Threading.Thread.GetDomain().DefineDynamicAssembly(name, run)
    let mdl = builder.DefineDynamicModule "tmpModule"
    let attrs = TypeAttributes.Public ||| TypeAttributes.Class
    mdl.DefineType(typeName, attrs);;
val createType : string -> TypeBuilder