Is there a functional language for C++ ecosystem?

Question

Java has Scala and .NET has F#. Both of these languages are very highly integrated into the respective Java and .NET platforms. Classes can be written in Scala then extended i

Answer 1

As has been said, I'm not really sure about a C++ 'ecosystem'. But Haskell does have a Foreign Function Interface that allows you to call C functions from Haskell and Haskell functions from C.

Then again, that's C, I'm not really sure how far along the C++ FFI is...

Answer 2

This question was posted in 2008. For reference, C++11 onwards have support for functional programming. See another discussion updated for this Functional Programming in C++

Answer 3

C++ doesn't have an ecosystem in the sense of Java or .NET. There's no virtual machine, no runtime environment even, there's only a highly specialized standard library that by design doesn't operate well in a purely functional environment. C++ doesn't even have an ABI standard.

All things considered, I'm not sure what you mean/expect.

Answer 4

The 'D' language was designed as a successor to C++. A purely functional subset of D is being developed by Andrei Alexandrescu for D 2.0. I am guessing D interoperates well with C++.

Answer 5

C++ may not be a pure functional language, but parts of STL are certainly functional.

See Bjarne Stroustrup FAQ (the inventor of the c++)

Answer 6

The Felix language by John Skaller is designed to interoperate with C++ and provide the functional paradigm.

There are problems with doing this though. Functional languages provide first-class functions which allow the creation of closures: functions that have captured and carry values from the environment they were defined in. This makes it impossible to determine the lifetimes of values statically (because a closure might carry a value out of its scope) and, consequently, effectively requires a garbage collector but C++ is not garbage collected.