@@ -378,57 +378,35 @@ separated by PRED."
#:allow-other-keys)
"Generate a stream of package expressions for PACKAGE-NAME and all its
dependencies."
- (receive (package . dependencies)
- (repo->guix-package package-name repo)
- (if (not package)
- stream-null
-
- ;; Generate a lazy stream of package expressions for all unknown
- ;; dependencies in the graph.
- (let* ((make-state (lambda (queue done)
- (cons queue done)))
- (next (match-lambda
- (((next . rest) . done) next)))
- (imported (match-lambda
- ((queue . done) done)))
- (done? (match-lambda
- ((queue . done)
- (zero? (length queue)))))
- (unknown? (lambda* (dependency #:optional (done '()))
- (and (not (member dependency
- done))
- (null? (find-packages-by-name
- (guix-name dependency))))))
- (update (lambda (state new-queue)
- (match state
- (((head . tail) . done)
- (make-state (lset-difference
- equal?
- (lset-union equal? new-queue tail)
- done)
- (cons head done)))))))
- (stream-cons
- package
- (stream-unfold
- ;; map: produce a stream element
- (lambda (state)
- (repo->guix-package (next state) repo))
-
- ;; predicate
- (negate done?)
-
- ;; generator: update the queue
- (lambda (state)
- (receive (package . dependencies)
- (repo->guix-package (next state) repo)
- (if package
- (update state (filter (cut unknown? <>
- (cons (next state)
- (imported state)))
- (car dependencies)))
- ;; TODO: Try the other archives before giving up
- (update state (imported state)))))
-
- ;; initial state
- (make-state (filter unknown? (car dependencies))
- (list package-name))))))))
+ (define (exists? dependency)
+ (not (null? (find-packages-by-name (guix-name dependency)))))
+ (define initial-state (list #f (list package-name) (list)))
+ (define (step state)
+ (match state
+ ((prev (next . rest) done)
+ (define (handle? dep)
+ (and
+ (not (equal? dep next))
+ (not (member dep done))
+ (not (exists? dep))))
+ (receive (package . dependencies) (repo->guix-package next repo)
+ (list
+ (if package package '()) ;; default #f on failure would interrupt
+ (if package
+ (lset-union equal? rest (filter handle? (car dependencies)))
+ rest)
+ (cons next done))))
+ ((prev '() done)
+ (list #f '() done))))
+
+ ;; Generate a lazy stream of package expressions for all unknown
+ ;; dependencies in the graph.
+ (stream-unfold
+ ;; map: produce a stream element
+ (match-lambda ((latest queue done) latest))
+ ;; predicate
+ (match-lambda ((latest queue done) latest))
+ ;; generator: update the queue
+ step
+ ;; initial state
+ (step initial-state)))