Srfi

SRFI Skill

"SRFIs extend the Scheme programming language. You can help." — srfi.schemers.org

Scheme Requests for Implementation: portable library specifications with GF(3) categorization.

Overview

SRFIs are community-driven specifications that extend Scheme beyond R5RS/R6RS/R7RS. Each SRFI has a unique number, status (draft/final/withdrawn), and reference implementation.

Core SRFIs by Category

Data Structures [MINUS: -1]

Control Flow [ERGODIC: 0]

Syntax & Macros [PLUS: +1]

I/O & System [MINUS: -1]

Numeric [ERGODIC: 0]

Testing & Debugging [PLUS: +1]

Pattern Matching [PLUS: +1]

GF(3) Distribution

MINUS (-1):  Data Structures, I/O & System
ERGODIC (0): Control Flow, Numeric
PLUS (+1):   Syntax & Macros, Testing, Pattern Matching

Conservation: Σ(categories) ≡ 0 (mod 3) when balanced usage

R7RS-Large Libraries (Red/Tangerine Editions)

R7RS-Large incorporates SRFIs as standard libraries:

Red Edition (2019)

• (scheme list) ← SRFI 1
• (scheme vector) ← SRFI 133
• (scheme sort) ← SRFI 132
• (scheme set) ← SRFI 113
• (scheme charset) ← SRFI 14
• (scheme hash-table) ← SRFI 125
• (scheme ilist) ← SRFI 116
• (scheme rlist) ← SRFI 101
• (scheme ideque) ← SRFI 134
• (scheme text) ← SRFI 135
• (scheme generator) ← SRFI 158
• (scheme lseq) ← SRFI 127
• (scheme stream) ← SRFI 41
• (scheme box) ← SRFI 111
• (scheme list-queue) ← SRFI 117
• (scheme comparator) ← SRFI 128

Tangerine Edition (2021)

• (scheme bitwise) ← SRFI 151
• (scheme fixnum) ← SRFI 143
• (scheme flonum) ← SRFI 144
• (scheme division) ← SRFI 141
• (scheme bytevector) ← R6RS
• (scheme mapping) ← SRFI 146
• (scheme regex) ← SRFI 115

Implementation Support Matrix

SRFI-27: Random Sources (Key for Gay.jl Bridge)

;; SRFI-27 provides the abstraction layer for splittable RNG
(import (srfi 27))

;; Create a random source with specific seed
(define my-source (make-random-source))
(random-source-pseudo-randomize! my-source 1069 42)

;; Get integers and reals
(define rand-int (random-source-make-integers my-source))
(define rand-real (random-source-make-reals my-source))

;; GF(3) trit from random source
(define (random-trit source)
  (- ((random-source-make-integers source) 3) 1))

SRFI-171: Transducers

;; Composable sequence transformations
(import (srfi 171))

;; Filter, map, take composed
(define xform
  (compose
    (tfilter even?)
    (tmap (lambda (x) (* x x)))
    (ttake 5)))

;; Apply to list
(list-transduce xform rcons '(1 2 3 4 5 6 7 8 9 10))
;; => (4 16 36 64 100)

SRFI-204: Pattern Matching

(import (srfi 204))

;; Destructuring with guards
(match '(1 2 3)
  ((x y z) (guard (< x y z)) (list z y x))
  (_ 'no-match))
;; => (3 2 1)

;; Quasiquote patterns
(match '(lambda (x) (+ x 1))
  (`(lambda (,var) (+ ,var 1)) var)
  (_ #f))
;; => x

Integration with Little Schemer

Commands

# Search SRFIs by keyword
srfi search "hash table"

# Show SRFI abstract
srfi show 125

# Clone SRFI implementation
srfi clone 171

# Open in browser
srfi open 204

# List all final SRFIs
srfi list --status final

References

• srfi.schemers.org - Official SRFI home
• docs.scheme.org/srfi/support - Implementation matrix
• R7RS-Large - Standard incorporation
• Practical Scheme SRFI Cross-Reference

REPL atlas

Part of: repl-commons. Family canonical: guile.