Hy (programming language)

Hy
Hy logo – Cuddles the cuttlefish
Paradigm	Multi-paradigm: procedural, functional, object-oriented, meta, reflective, generic
Family	Lisp
Designed by	Paul Tagliamonte
Developers	Core team
First appeared	2013 (2013)
Scope	lexical, optionally dynamic
Platform	IA-32, x86-64
OS	Cross-platform
License	MIT-style
Filename extensions	.hy
Website	hylang.org
Influenced by
Kawa, Clojure, Common Lisp

Hy is a dialect of the Lisp programming language designed to interact with Python by translating s-expressions into Python's abstract syntax tree (AST). Hy was introduced at Python Conference (PyCon) 2013 by Paul Tagliamonte. Lisp allows operating on code as data (metaprogramming), thus Hy can be used to write domain-specific languages.

Similar to Kawa's and Clojure's mappings onto the Java virtual machine (JVM), Hy is meant to operate as a transparent Lisp front-end for Python. It allows Python libraries, including the standard library, to be imported and accessed alongside Hy code with a compiling step where both languages are converted into Python's AST.

Example code

From the language documentation:

=> (print "Hy!")
Hy!
=> (defn salutationsnm [name] (print (+ "Hy " name "!")))
=> (salutationsnm "YourName")
Hy YourName!

See also

• Common Lisp
• Clojure
• Kawa (Scheme implementation)
• CLPython

External links

• Official website
• hy on GitHub
• Documentation
• Video of 2014 PyCon talk