What is husk?

husk is a practical implementation of the Scheme programming language for the Haskell Platform. A superset of the R⁵RS standard is provided, along with most of the R⁷RS standard. Advanced features include:

• First-class continuations of unlimited extent
• Hygienic macros based on syntax-rules
• Low-level explicit renaming macros
• Library syntax from the R⁷RS standard
• A foreign function interface (FFI) to Haskell
• Full numeric tower providing support for real, rational, and complex numbers
• Proper tail recursion and lexical scoping
• Read-Eval-Print-Loop (REPL) interpreter, with input driven by Haskeline to provide a rich user experience
• Standard library of Scheme functions, and support for many popular SRFI's

Husk may be used as either a stand-alone interpreter or as an extension language within a larger Haskell application, and is available under the MIT license.

Background

Scheme is one of two main dialects of Lisp. Scheme follows a minimalist design philosophy, with the core language consisting of a small number of fundamental forms. Scheme is an excellent language for writing small, elegant programs, and may also be used to develop domain-specific languages or embed scripting functionality within a larger application.