Compilers and Languages

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Functional Programming Paradigm

Languages Supporting Functional Programming

functional programming language based on the lambda calculus

Functional programming language based on the lambda calculus.

Functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids changing-state and mutable data. This unit provides an overview of functional programming languages and a deep dive into select languages that support this paradigm.

Overview of Functional Programming Languages

Functional programming languages are designed on the concept of mathematical functions that use conditional expressions and recursion to perform computation. They emphasize the application of functions, in contrast to the imperative programming style, which emphasizes changes in state.

Functional programming languages are categorized into pure and impure functional languages. Pure functional languages do not allow side-effects, whereas impure functional languages allow side-effects.

Deep Dive into Select Functional Programming Languages


Lisp, developed in the late 1950s, is one of the oldest high-level programming languages and the first choice for many when it comes to functional programming. Lisp is known for its unique syntax where code and data are written in the same way. It supports a wide range of programming paradigms, including functional programming.


Haskell is a standardized, general-purpose, purely functional programming language, with non-strict semantics and strong static typing. It is named after Haskell Curry, a logician who contributed significantly to the development of combinatory logic, a concept used heavily in functional programming.


Erlang is a functional, concurrent, general-purpose programming language and runtime system. It was designed by Ericsson to support distributed, fault-tolerant, soft-real-time, non-stop applications. It supports hot swapping, allowing code to be changed without stopping the system.


Scala is a modern multi-paradigm programming language designed to express common programming patterns in a concise, elegant, and type-safe way. It smoothly integrates features of object-oriented and functional languages, enabling programmers to be more productive.


Clojure is a robust, practical, and fast programming language with a set of useful features that together form a simple, coherent, and powerful tool. It is a dialect of Lisp and emphasizes functional programming.

Comparison of Functional Programming Languages

While all functional programming languages share some characteristics, they also have unique features that set them apart. For instance, Lisp is known for its macro system, which allows programmers to create new syntax and language constructs. Haskell, on the other hand, is known for its strong static typing and purity, which can prevent side-effects. Erlang is recognized for its concurrency and fault-tolerance, making it ideal for telecommunication systems. Scala combines object-oriented and functional programming, making it a versatile choice. Clojure, being a dialect of Lisp, offers the power of Lisp with the convenience of running on the Java Virtual Machine (JVM).

In conclusion, the choice of a functional programming language depends on the specific requirements of the project, the features of the language, and the preference of the development team.