diff options
| -rw-r--r-- | gtwiwtg.lisp | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/gtwiwtg.lisp b/gtwiwtg.lisp index fe60d53..35f830d 100644 --- a/gtwiwtg.lisp +++ b/gtwiwtg.lisp @@ -182,7 +182,7 @@ of the sequence." :sequence sequence :index (1- start)))) -(defun from-thunk-until (thunk &optional (until (constantly nil)) clean-up) +(defun from-thunk-until (thunk &key (until (constantly nil)) clean-up) "Creates a generator that produces a series of value by successively calling (FUNCALL THUNK). The iterator stops whenever (FUNCALL UNTIL) is non null. @@ -374,8 +374,10 @@ Error Conditions: (from-thunk-until (lambda () (apply map-fn (mapcar #'next all-gens))) + :until (lambda () (some (complement #'has-next-p) all-gens)) ; when at least one has no next value + :clean-up (lambda () (dolist (g all-gens) (stop g)))))) @@ -390,6 +392,8 @@ Error Condition: (let (on-deck) (from-thunk-until (lambda () on-deck) ; consumers always call has-next-p before next + + :until (lambda () (loop :while (has-next-p gen) @@ -399,6 +403,8 @@ Error Condition: (setf on-deck candidate) (return nil)) ; Don't stop generating, we found one :finally (return t))) ; Stop generating, we can't find one. + + :clean-up (lambda () (stop gen))))) @@ -434,6 +440,7 @@ Error Conditions: (from-thunk-until (lambda () (next sub-gen)) + :until (lambda () (loop :until (has-next-p sub-gen) @@ -446,7 +453,8 @@ Error Conditions: ;; hence: (not (or (has-next-p sub-gen) (has-next-p gen)))) - + + :clean-up (lambda () (stop gen) (when sub-gen (stop sub-gen))))))) @@ -509,9 +517,11 @@ Error Conditions: all-gens))) (car vals))) + :until (lambda () (null all-gens)) + :clean-up (lambda () (dolist (g all-gens) (stop g)))))) @@ -590,10 +600,12 @@ Caveat: (t (error "Attempted to get next from a spent generator.")))) + :until (lambda () (and (not (has-next-p source-generator)) (queue-empty-p local-q))) + :clean-up (lambda () (setf (car local-stop) t) (when (every #'car stop-cells) |