Pointfree programming

Pointfree programming, point-free programming, or tacit programming is a style of programming which doesn't use bindings (names) for local variables or function arguments. Instead, programmers manipulate values in other ways, such as by composing builtin functions.

Pointfree programming is mandatory in several programming languages as a matter of syntax. It is also a possible or preferred style in some programming communities.

Concatenative languages

In concatenative languages, programs are built from combinations of operators which operate upon a single shared environment. In the Forth tradition, the environment is a pair of stacks, and languages like Underload or catlangwiki:Joy avoid the need for variables by providing a complete basis of operators which can rearrange the stack arbitrarily.

Some point-free languages which descend from Forth have mutable variables and global variables. Examples include PostScript and J.

Functional languages

Languages in the functional paradigm are often point-free, because combinatory logic is usually point-free, with combinators like S or B providing composition of multi-argument functions and simulating currying. Languages which trace their heritage through combinators, like Miranda and Haskell, still practice point-free techniques today. Some languages such as Amicus don't have currying; instead, functions take a tuple and the primitive forms compose multi-argument functions. FP is a programming language that was built on this archetype and uses tuples. Still other languages, such as Cammy, have both currying and tuples.

APL

APL has a tacit style which encourages the definition of names for new operators, but not for variables. APL derivatives like Jelly, J, and K continue this tradition.

Dataflow languages

Languages which focus on the flow of data through a system, rather than expressing control flow, can have tacit styles which focus on modular filters. jq is a popular example. Outside programming, modular synthesis is a revolutionary technique for creating new musical instruments.