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| author | Ludovic Courtès <ludo@gnu.org> | 2012-07-01 17:32:03 +0200 |
|---|---|---|
| committer | Ludovic Courtès <ludo@gnu.org> | 2012-07-03 21:59:56 +0200 |
| commit | 8fd5bd2b69b51e370144f26c01201a178c024483 (patch) | |
| tree | 3889c1a00d30d2c5e51286c83536ee71c5a01149 | |
| parent | e4c245f8a5f6b6485f980b9c4274909ee8ef567a (diff) | |
| download | guix-8fd5bd2b69b51e370144f26c01201a178c024483.tar.gz guix-8fd5bd2b69b51e370144f26c01201a178c024483.zip | |
define-record-type*: Add `letrec*' behavior.
* guix/utils.scm (define-record-type*)[make-syntactic-constructor]: Bind
all the ((FIELD VALUE) ...) in a `letrec*'. Adjust `field-value'
accordingly.
* tests/utils.scm ("define-record-type* with letrec* behavior"): New
test.
| -rw-r--r-- | guix/utils.scm | 29 | ||||
| -rw-r--r-- | tests/utils.scm | 16 |
2 files changed, 30 insertions, 15 deletions
diff --git a/guix/utils.scm b/guix/utils.scm index ed13bae307..3d92bac9cc 100644 --- a/guix/utils.scm +++ b/guix/utils.scm @@ -479,20 +479,18 @@ tuples." (lambda (s) (syntax-case s expected ((_ (field value) (... ...)) - (let ((fields (map syntax->datum #'(field (... ...)))) - (inits (map (match-lambda - ((f v) - (list (syntax->datum f) v))) - #'((field value) (... ...)))) - (dflt (map (match-lambda - ((f v) - (list (syntax->datum f) v))) - #'defaults))) - - (define (field-value f) - (match (assoc f inits) - ((_ v) v) - (#f (car (assoc-ref dflt f))))) + (let ((fields (map syntax->datum #'(field (... ...)))) + (dflt (map (match-lambda + ((f v) + (list (syntax->datum f) v))) + #'defaults))) + + (define (field-value f) + (or (and=> (find (lambda (x) + (eq? f (car (syntax->datum x)))) + #'((field value) (... ...))) + car) + (car (assoc-ref dflt (syntax->datum f))))) (let-syntax ((error* (syntax-rules () @@ -503,7 +501,8 @@ tuples." s))))) (let ((fields (append fields (map car dflt)))) (cond ((lset= eq? fields 'expected) - #`(ctor #,@(map field-value 'expected))) + #`(letrec* ((field value) (... ...)) + (ctor #,@(map field-value 'expected)))) ((pair? (lset-difference eq? fields 'expected)) (error* "extraneous field initializers ~a" (lset-difference eq? fields 'expected))) diff --git a/tests/utils.scm b/tests/utils.scm index 83a78b7a78..4a24e23df9 100644 --- a/tests/utils.scm +++ b/tests/utils.scm @@ -112,6 +112,22 @@ (match (foo (bar 1)) (($ <foo> 1 42) #t))))) +(test-assert "define-record-type* with letrec* behavior" + ;; Make sure field initializers can refer to each other as if they were in + ;; a `letrec*'. + (begin + (define-record-type* <bar> bar make-bar + foo? + (x bar-x) + (y bar-y (default (+ 40 2))) + (z bar-z)) + (and (match (bar (x 1) (y (+ x 1)) (z (* y 2))) + (($ <bar> 1 2 4) #t)) + (match (bar (x 7) (z (* x 3))) + (($ <bar> 7 42 21))) + (match (bar (z 21) (x (/ z 3))) + (($ <bar> 7 42 21)))))) + (test-end) |