chibi-scheme/lib/srfi/11.sld
2020-07-28 15:26:42 +09:00

28 lines
1.3 KiB
Scheme

(define-library (srfi 11)
(export let-values let*-values)
(import (chibi))
(begin
(define-syntax let*-values
(syntax-rules ()
((let*-values () . body)
(let () . body))
((let*-values (((a) expr) . rest) . body)
(let ((a expr)) (let*-values rest . body)))
((let*-values ((params expr) . rest) . body)
(call-with-values (lambda () expr)
(lambda params (let*-values rest . body))))))
(define-syntax let-values
(syntax-rules ()
((let-values () . body)
(let () . body))
((let-values ("step") (binds ...) bind expr maps () () . body)
(let*-values (binds ... (bind expr)) (let maps . body)))
((let-values ("step") (binds ...) bind old-expr maps () ((params expr) . rest) . body)
(let-values ("step") (binds ... (bind old-expr)) () expr maps params rest . body))
((let-values ("step") binds (bind ...) expr (maps ...) (x . y) rest . body)
(let-values ("step") binds (bind ... tmp) expr (maps ... (x tmp)) y rest . body))
((let-values ("step") binds (bind ...) expr (maps ...) x rest . body)
(let-values ("step") binds (bind ... . tmp) expr (maps ... (x tmp)) () rest . body))
((let-values ((params expr) . rest) . body)
(let-values ("step") () () expr () params rest . body))))))