Fref

Fref is a term used in certain programming discussions to denote a reference to a function—essentially, a value that represents a callable rather than the result of calling it. The term is informal rather than a formal keyword in mainstream languages, and its exact meaning can vary by context.

Origins and usage

The concept of treating functions as first-class values long predates modern languages. In many explanations, fref serves as a shorthand to emphasize that a function can be passed, stored, or returned just like any other data. In API design and documentation, fref may appear to distinguish a function reference from a function result, a memory reference, or a plain value.

Representation

In statically typed languages with first-class functions, a fref may have a type such as a function type or a dedicated wrapper that includes the callable along with related metadata (for example, arity, closure context, or origin module). In dynamic languages, the function object itself acts as the fref, since the language treats functions as first-class citizens.

Common uses

Typical applications include passing callbacks, storing handlers in collections, returning function references from APIs, and deferring execution. Distinguishing an fref from a mutable reference (ref) highlights a focus on behavior and invocation rather than on memory location.

See also

First-class function, function pointer, callback, closure, higher-order function.