Hy
Hy (alternately, Hylang) is a programming language, a dialect of the language Lisp designed to interact with the language Python by translating expressions into Python's abstract syntax tree (AST).[1] Hy was introduced at Python Conference (PyCon) 2013 by Paul Tagliamonte.[2]
 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 |
| Preview release | 0.18.0
/ 2 February 2020 |
| Scope | lexical, optionally dynamic |
| Platform | IA-32, x86-64 |
| OS | Cross-platform |
| License | MIT-style |
| Filename extensions | .hy |
| Website | hylang |
| Influenced by | |
| Lisp, Kawa, Clojure, Common Lisp | |
Similar to Kawa's and Clojure's mapping of s-expressions onto the Java virtual machine (JVM),[3] Hy is meant to operate as a transparent Lisp front end to Python's abstract syntax.[4] Lisp allows operating on code as data (metaprogramming). Thus, Hy can be used to write domain-specific languages.[5] Hy also allows Python libraries, including the standard library, to be imported and accessed alongside Hy code with a compiling[note 1] step converting the data structure of both into Python's AST.[note 2][6][7][8]
Example code
From the language documentation:[9]
=> (print "Hy!")
Hy!
=> (defn salutationsnm [name] (print (+ "Hy " name "!")))
=> (salutationsnm "YourName")
Hy YourName!
Notes
- "Compiled" is a term which may apply to expressing Hy code in Python's AST or converting that AST into bytecode, the latter being dependent on the specific Python interpreter used and not Hy.
- Hy is tested on Python 2.7, 3.4 through 3.6, and PyPy.
References
- Danjou, Julien (2018). Serious Python: black-belt advice on deployment, scalability, testing, and more. San Francisco, CA: No Starch Press. pp. 145–149. ISBN 9781593278793. OCLC 1057729260.
- Tagliamonte, Paul (2 April 2013). PyCon lightning talk (Speech). Python Conference (PyCon). Santa Clara. Retrieved 2 September 2014.
- Turto, Tuukka (14 February 2014). "Programming Can Be Fun with Hy". Open Source For You. Retrieved 2 September 2014.
- Edge, Jake (30 April 2014). "Getting Hy on Python". LWN.net. Retrieved 2 September 2014.
- Tagliamonte, Paul (11 April 2014). Getting Hy on Python: How to implement a Lisp front-end to Python (Speech). PyCon. Montreal. Retrieved 2 September 2014.
- "Hy Documentation". hylang.org. Retrieved 3 September 2014.
- Danjou, Julien (26 March 2014). "The AST". The Hacker's Guide to Python. pp. 165–172.
- Kitchin, John (31 March 2016). "More on Hy and why I think it is a big deal". The Kitchin Research Group. Carnegie Mellon University. Retrieved 19 September 2018.
- "Quickstart". Hylang.org. 15 May 2018. Retrieved 19 September 2018.
