# HG changeset patch
# User Steve Losh <steve@stevelosh.com>
# Date 1471898360 0
# Node ID 1d59a2656cfc0ad01d7f62cf835c3ce7f41c14a5
# Parent  7eb23163afcfa2d5fa7d4e474ea325330a11bbbb
Use `ensure-gethash`

diff -r 7eb23163afcf -r 1d59a2656cfc src/binary-decision-diagrams.lisp
--- a/src/binary-decision-diagrams.lisp	Sun Aug 21 18:14:23 2016 +0000
+++ b/src/binary-decision-diagrams.lisp	Mon Aug 22 20:39:20 2016 +0000
@@ -72,7 +72,7 @@
   (let ((nodes (make-hash-table)))
     (graphviz-digraph
       (bdd-map-nodes (lambda (node)
-                       (list (gethash-or-init node nodes (gensym))
+                       (list (ensure-gethash node nodes (gensym))
                              :label (node-label node)
                              :shape (node-shape node)))
                      bdd)
diff -r 7eb23163afcf -r 1d59a2656cfc vendor/make-quickutils.lisp
--- a/vendor/make-quickutils.lisp	Sun Aug 21 18:14:23 2016 +0000
+++ b/vendor/make-quickutils.lisp	Mon Aug 22 20:39:20 2016 +0000
@@ -12,6 +12,7 @@
                :define-constant
                :riffle
                :tree-collect
+               :ensure-gethash
                ; :switch
                ; :while
                ; :ensure-boolean
diff -r 7eb23163afcf -r 1d59a2656cfc vendor/quickutils.lisp
--- a/vendor/quickutils.lisp	Sun Aug 21 18:14:23 2016 +0000
+++ b/vendor/quickutils.lisp	Mon Aug 22 20:39:20 2016 +0000
@@ -2,7 +2,7 @@
 ;;;; See http://quickutil.org for details.
 
 ;;;; To regenerate:
-;;;; (qtlc:save-utils-as "quickutils.lisp" :utilities '(:WITH-GENSYMS :ONCE-ONLY :COMPOSE :CURRY :RCURRY :N-GRAMS :DEFINE-CONSTANT :RIFFLE :TREE-COLLECT) :ensure-package T :package "SAND.QUICKUTILS")
+;;;; (qtlc:save-utils-as "quickutils.lisp" :utilities '(:WITH-GENSYMS :ONCE-ONLY :COMPOSE :CURRY :RCURRY :N-GRAMS :DEFINE-CONSTANT :RIFFLE :TREE-COLLECT :ENSURE-GETHASH) :ensure-package T :package "SAND.QUICKUTILS")
 
 (eval-when (:compile-toplevel :load-toplevel :execute)
   (unless (find-package "SAND.QUICKUTILS")
@@ -17,7 +17,8 @@
                                          :MAKE-GENSYM-LIST :ONCE-ONLY
                                          :ENSURE-FUNCTION :COMPOSE :CURRY
                                          :RCURRY :TAKE :N-GRAMS
-                                         :DEFINE-CONSTANT :RIFFLE :TREE-COLLECT))))
+                                         :DEFINE-CONSTANT :RIFFLE :TREE-COLLECT
+                                         :ENSURE-GETHASH))))
 
   (deftype string-designator ()
     "A string designator type. A string designator is either a string, a symbol,
@@ -268,8 +269,18 @@
                   :if (listp item)
                     :append (tree-collect predicate item)))))
   
+
+  (defmacro ensure-gethash (key hash-table &optional default)
+    "Like `gethash`, but if `key` is not found in the `hash-table` saves the `default`
+under key before returning it. Secondary return value is true if key was
+already in the table."
+    `(multiple-value-bind (value ok) (gethash ,key ,hash-table)
+       (if ok
+           (values value ok)
+           (values (setf (gethash ,key ,hash-table) ,default) nil))))
+  
 (eval-when (:compile-toplevel :load-toplevel :execute)
   (export '(with-gensyms with-unique-names once-only compose curry rcurry
-            n-grams define-constant riffle tree-collect)))
+            n-grams define-constant riffle tree-collect ensure-gethash)))
 
 ;;;; END OF quickutils.lisp ;;;;