LiveScript (programming language)

From Wikipedia, the free encyclopedia
Paradigmmulti-paradigm, functional, object-oriented
Designed byJeremy Ashkenas, Satoshi Murakami, George Zahariev
DeveloperJeremy Ashkenas, Satoshi Murakami, George Zahariev
First appeared2011; 13 years ago (2011)
Stable release
LiveScript 1.6.1 / 14 July 2020; 3 years ago (2020-07-14)[1]
Typing disciplinedynamic, weak
Influenced by
JavaScript, Haskell, CoffeeScript, F#

LiveScript is a functional programming language that transpiles to JavaScript. It was created by Jeremy Ashkenas—the creator of CoffeeScript—along with Satoshi Muramaki, George Zahariev, and many others.[2] (The name may be an homage to the beta name of JavaScript; for a few months in 1995, it was called LiveScript before the official release.[3])


LiveScript is an indirect descendant of CoffeeScript.[4] The following "Hello, World!" program is written in LiveScript, but is also compatible with Coffeescript:

hello = ->
  console.log 'hello, world!'

While calling a function can be done with empty parens, hello(), LiveScript treats the exclamation mark as a single-character shorthand for function calls with zero arguments: hello!

LiveScript introduces a number of other incompatible idioms:

Name mangling[edit]

At compile time, the LiveScript parser implicitly converts kebab case (dashed variables and function names) to camel case.

hello-world = ->
  console.log 'Hello, World!'

With this definition, both the following calls are valid. However, calling using the same dashed syntax is recommended.


This does not preclude developers from using camel case explicitly or using snake case. Dashed naming is however, common in idiomatic LiveScript[5]


Like a number of other functional programming languages such as F# and Elixir, LiveScript supports the pipe operator, |> which passes the result of the expression on the left of the operator as an argument to the expression on the right of it. Note that in F# the argument passed is the last argument, while in Elixir it is the first.

"hello!" |> capitalize |> console.log
# > Hello!

Operators as functions[edit]

When parenthesized, operators such as not or + can be included in pipelines or called as if they were functions.

111 |> (+) 222
# > 333

(+) 1 2
# > 3


  1. ^ "LiveScript Releases". GitHub. Retrieved 21 February 2021.
  2. ^ "LiveScript contributors page". GitHub. Retrieved 20 June 2015.
  3. ^ "Chapter 4. How JavaScript Was Created". Archived from the original on 2020-02-27. Retrieved 2017-11-21.
  4. ^ "LiveScript - a language which compiles to JavaScript".
  5. ^ " - a functionally oriented utility library in LiveScript".

External links[edit]