In programming languages, defunctionalization refers to a compile-time transformation which eliminates higher-order functions, replacing them by a single first-order apply function. The technique was first described by John C. Reynolds in his 1972 paper, "Definitional Interpreters for Higher-Order Programming Languages". Reynolds' observation was that a given program contains only finitely many function abstractions, so that each can be assigned (and replaced by) a unique identifier.
more from Wikipedia
Lambda lifting
Lambda lifting or closure conversion is the process of eliminating free variables from local function definitions from a computer program. The elimination of free variables allows the compiler to hoist local definitions out of their surrounding contexts into a fixed set of top-level functions with an extra parameter replacing each local variable. By eliminating the need for run-time access-links, this may reduce the run-time cost of handling implicit scope.
more from Wikipedia
System F
System F, also known as the (Girard¿Reynolds) polymorphic lambda calculus or the second-order lambda calculus, is a typed lambda calculus that differs from the simply typed lambda calculus by the introduction of a mechanism of universal quantification over types. System F thus formalizes the notion of parametric polymorphism in programming languages, and forms a theoretical basis for languages such as Haskell and ML.
more from Wikipedia
Closure (computer science)
In computer science, a closure (also lexical closure or function closure) is a function together with a referencing environment for the non-local variables of that function. A closure allows a function to access variables outside its immediate lexical scope. An upvalue is a free variable that has been bound (closed over) with a closure. The closure is said to "close over" its upvalues.
more from Wikipedia
Higher-order function
In mathematics and computer science, a higher-order function (also functional form, functional or functor) is a function that does at least one of the following: take one or more functions as an input output a function All other functions are first order functions. In mathematics higher-order functions are also known as operators or functionals. The derivative in calculus is a common example, since it maps a function to another function.
more from Wikipedia
Algebraic data type
In computer programming, particularly functional programming and type theory, an algebraic data type (sometimes also called a variant type) is a datatype each of whose values is data from other datatypes wrapped in one of the constructors of the datatype. Any wrapped datum is an argument to the constructor. In contrast to other datatypes, the constructor is not executed and the only way to operate on the data is to unwrap the constructor using pattern matching.
more from Wikipedia
ML (programming language)
ML is a general-purpose functional programming language developed by Robin Milner and others in the early 1970s at the University of Edinburgh, whose syntax is inspired by ISWIM. Historically, ML stands for metalanguage: it was conceived to develop proof tactics in the LCF theorem prover (whose language, pplambda, a combination of the first-order predicate calculus and the simply typed polymorphic lambda calculus, had ML as its metalanguage).
more from Wikipedia