diff options
| -rw-r--r-- | gtwiwtg.lisp | 40 |
1 files changed, 16 insertions, 24 deletions
diff --git a/gtwiwtg.lisp b/gtwiwtg.lisp index 2cba70d..657de5b 100644 --- a/gtwiwtg.lisp +++ b/gtwiwtg.lisp @@ -333,6 +333,10 @@ Returns NIL on the last iteration. (defun all-good (gens) (and (all-clean gens) (all-different gens))) +(defun sully-when-clean (gens) + (assert (all-good gens)) + (dolist (g gens) (make-dirty g))) + ;;; MODIFIERS and COMBINATORS (defun map! (map-fn gen &rest gens) @@ -350,13 +354,12 @@ Error Conditions: - If any of the generators have been used elsewhere, an error will be signalled. " (let ((all-gens (list* gen gens))) - (assert (all-good all-gens)) - (dolist (g all-gens) (make-dirty g)) + (sully-when-clean all-gens) (from-thunk-until (lambda () (apply map-fn (mapcar #'next all-gens))) (lambda () - (some (complement #'has-next-p) all-gens)) + (some (complement #'has-next-p) all-gens)) ; when at least one has no next value (lambda () (dolist (g all-gens) (stop g)))))) @@ -367,11 +370,10 @@ when applied to PRED. Error Condition: - If GEN has been used elsewhere, an error will be signalled. " - (assert (not (dirty-p gen))) - (make-dirty gen) + (sully-when-clean (list gen)) (let (on-deck) (from-thunk-until - (lambda () on-deck) + (lambda () on-deck) ; consumers always call has-next-p before next (lambda () (loop :while (has-next-p gen) @@ -379,8 +381,8 @@ Error Condition: :when (funcall pred candidate) :do (progn (setf on-deck candidate) - (return nil)) - :finally (return t))) + (return nil)) ; Don't stop generating, we found one + :finally (return t))) ; Stop generating, we can't find one. (lambda () (stop gen))))) @@ -406,10 +408,9 @@ Here is an example: Error Conditions: - If GEN has been used elsewhere, an error will be signalled. + - If GEN is an empty generator, an error will be signalled. " - (assert (not (dirty-p gen))) - (make-dirty gen) - + (sully-when-clean (list gen)) (let ((sub-gen (funcall fn (next gen)))) (from-thunk-until (lambda () (next sub-gen)) @@ -426,6 +427,7 @@ Error Conditions: ;; hence: (not (or (has-next-p sub-gen) (has-next-p gen)))) + (lambda () (stop gen) (when sub-gen (stop sub-gen)))))) @@ -435,18 +437,11 @@ Error Conditions: "Returns a generator that is the concatenation of the generators passed as arguments. -Each of the arguments to CONCAT! must be different. If any compare -EQL, an error will be signalled. - Error Conditions: - If any of the generators compare EQL, an error will be signalled. - If any of the generators has been used elsewhere, an error will be sigalled. - -Caveat: - - CONCAT! Modifies and returns its first argument. " - (assert (all-good (list* gen gens))) - (dolist (g (list* gen gens)) (make-dirty g)) + (sully-when-clean (list* gen gens)) (inflate! #'identity (seq (list* gen gens)))) (defun zip! (gen &rest gens) @@ -476,13 +471,10 @@ An example: Error Conditions: - If any of the generators compare EQL, an error will be signalled. - - If any of the generators have been used elsewhere, an errror will be signalled. + - If any of the generators have been used elsewhere, an error will be signalled. " (let ((all-gens (list* gen1 gen2 gens))) - - (assert (all-good all-gens)) - (dolist (g all-gens) (make-dirty g)) - + (sully-when-clean all-gens) (from-thunk-until (lambda () (let ((vals (mapcar #'next all-gens))) |