Lazy ML is a functional programming language

Programming language

A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....

 developed in the early 1980s by Lennart Augustsson

Lennart Augustsson

Lennart Augustsson is a Swedish computer scientist. He was previously a lecturer at the Computing Science Department at Chalmers University of Technology...

 and Thomas Johnsson at Chalmers University of Technology

Chalmers University of Technology

Chalmers University of Technology , is a Swedish university located in Gothenburg that focuses on research and education in technology, natural science and architecture.-History:...

, prior to Miranda

Miranda programming language

Miranda is a non-strict purely functional programming language designed by David Turner as a successor to his earlier programming languages SASL and KRC, using some concepts from ML and Hope. It was produced by Research Software Ltd...

 and Haskell

Haskell (programming language)

Haskell is a standardized, general-purpose purely functional programming language, with non-strict semantics and strong static typing. It is named after logician Haskell Curry. In Haskell, "a function is a first-class citizen" of the programming language. As a functional programming language, the...

. LML is a strongly typed, statically scoped implementation of ML, with lazy evaluation

Lazy evaluation

In programming language theory, lazy evaluation or call-by-need is an evaluation strategy which delays the evaluation of an expression until the value of this is actually required and which also avoids repeated evaluations...

.

The key innovation of LML was to demonstrate how to compile a lazy functional language. Until then, lazy languages had been implemented via interpreted graph reduction. LML compiled to G-machine code.

LML is also notable as the language in which HBC, the Haskell B Compiler, was implemented.

Example programs

Hello, world:

"hello world\n"

Factorial,

let rec fact 0 = 1 ||
fact n = n*fact(n-1)

External links

• Lazy ML (LML) Examples
• A Compiler for Lazy ML, Lennart Augustsson
  Lennart Augustsson
  Lennart Augustsson is a Swedish computer scientist. He was previously a lecturer at the Computing Science Department at Chalmers University of Technology...
  
  , Proceedings of the 1984 ACM Symposium on LISP and functional programming, 1984.