SRFI

SRFI stands for Scheme Request For Implementation. It is a process used by the Scheme programming language community to propose, discuss, and document extensions to the language and its standard libraries. A SRFI describes a concrete addition or change, including the problem it addresses, design goals, the chosen interface, and the rationale behind it. Each SRFI is assigned a number and published as a draft, with status such as draft, final, or accepted. A typical SRFI includes a specification, a reference implementation in Scheme, and a test suite.

Process and governance: Proposals are discussed on public mailing lists and forums, reviewed by the community, and maintained by an SRFI Editor or editors. Proposers may revise the draft in response to feedback. When consensus is reached, the SRFI progresses toward final status. Some SRFIs are considered essential core libraries and are adopted by multiple Scheme implementations; others remain optional or experimental.

Relation to standards and interoperability: SRFIs provide a mechanism for standardizing libraries and language features between major Scheme versions and across implementations, such as R5RS, R6RS, and R7RS. They support portability by encouraging code that relies on well-defined interfaces rather than implementation-specific details. Implementations often ship with a subset of SRFIs and may offer others as optional libraries or extensions.

Examples and scope: Notable areas covered by SRFIs include libraries for lists and sequences, strings, input/output, files, and numeric operations, among others. Some SRFIs have achieved wide availability across implementations and influenced later standards; others remain community-maintained and evolve over time.