| 1 | (define-syntax define-record |
| 2 | (lambda (e) |
| 3 | (syntax-case e () |
| 4 | ((_ name field0 field1 ...) |
| 5 | (with-syntax ((%fields |
| 6 | (map (lambda (f) |
| 7 | (syntax-case f () |
| 8 | ((fname) (syntax (field fname #f))) |
| 9 | ((fname default) (syntax (field fname default))) |
| 10 | (fname (syntax (field fname #f))))) |
| 11 | (syntax (field0 field1 ...))))) |
| 12 | (syntax |
| 13 | (define-record* name |
| 14 | %fields))))))) |
| 15 | |
| 16 | (define-syntax define-record* |
| 17 | (lambda (e) |
| 18 | (letrec ((make-name (lambda args |
| 19 | (datum->syntax e |
| 20 | (string->symbol |
| 21 | (apply string-append |
| 22 | (map (lambda (a) |
| 23 | (if (string? a) |
| 24 | a |
| 25 | (symbol->string |
| 26 | (syntax->datum a)))) |
| 27 | args))))))) |
| 28 | (syntax-case e (field) |
| 29 | ((_ name ((field field-name default) ...)) |
| 30 | #`(begin (define* (#,(make-name "make-" (syntax name)) |
| 31 | #:optional (field-name default) ...) |
| 32 | (vector 'name field-name ...)) |
| 33 | #,@(let ((idx 0)) |
| 34 | (map (lambda (fname) |
| 35 | (set! idx (1+ idx)) |
| 36 | #`(begin (define (#,(make-name (syntax name) |
| 37 | ":" |
| 38 | fname) |
| 39 | rec) |
| 40 | (vector-ref rec #,idx)) |
| 41 | (define (#,(make-name "set-" |
| 42 | (syntax name) |
| 43 | ":" |
| 44 | fname) |
| 45 | rec val) |
| 46 | (vector-set! rec #,idx val)))) |
| 47 | (syntax (field-name ...)))))))))) |
| 48 | |