diff options
| -rw-r--r-- | gtwiwtg.lisp | 34 | ||||
| -rw-r--r-- | package.lisp | 2 |
2 files changed, 36 insertions, 0 deletions
diff --git a/gtwiwtg.lisp b/gtwiwtg.lisp index c150a60..f52e7b9 100644 --- a/gtwiwtg.lisp +++ b/gtwiwtg.lisp @@ -102,6 +102,14 @@ If TIMES is supplied, THUNK will only be called TIMES times." (let ((thunk-proxy (lambda (ignore) (declare (ignore ignore)) (funcall thunk)))) (map! thunk-proxy (range :to (when times (1- times)))))) +(defun from-thunk-until (thunk until) + (make-instance 'generator! + :state nil + :next-p-fn (lambda (ignore) (declare (ignore ignore)) (not (funcall until))) + :next-fn (lambda (ignore) + (declare (ignore ignore)) + (values (funcall thunk) nil)))) + (defun from-recurrence (rec n-1 &rest n-m) "Creates a generator from a recurrence relation. @@ -399,6 +407,26 @@ CONCAT! MODIFIES AND RETURNS ITS FIRST ARGUMENT." + +(defun merge! (comparator gen1 gen2 &rest gens) + (let ((all-gens (list* gen1 gen2 gens))) + + (assert (all-good all-gens)) + (dolist (g all-gens) (make-dirty g)) + + (from-thunk-until + (lambda () + (let ((vals (mapcar #'next all-gens))) + (setq vals (sort vals comparator)) + + (setf all-gens + (delete-if-not #'has-next-p + (nconc (when (cdr vals) (list (seq (cdr vals)))) + all-gens))) + (car vals))) + (lambda () + (null all-gens))))) + ;;; CONSUMERS (defmacro iter ((var-exp gen) &body body) @@ -589,3 +617,9 @@ Not meant for general use. just a utility used by THREAD-THROUGH" (defun all-primes () (filter! #'prime-p (range :from 1))) + + +;; merge-sort + +(defun gen-sort (seq) + ()) diff --git a/package.lisp b/package.lisp index b0f7e21..ec55c79 100644 --- a/package.lisp +++ b/package.lisp @@ -8,6 +8,7 @@ #:repeater #:noise #:from-thunk + #:from-thunk-until #:from-recurrence #:from-input-stream #:file-lines @@ -19,6 +20,7 @@ #:inflate! #:concat! #:zip! + #:merge! #:iter #:fold #:collect |