1 files changed, 42 insertions, 0 deletions
diff --git a/stdlib/hash.tl b/stdlib/hash.tl
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+++ b/stdlib/hash.tl
@@ -0,0 +1,42 @@
+;; Copyright 2015-2021
+;; Kaz Kylheku <kaz@kylheku.com>
+;; Vancouver, Canada
+;; All rights reserved.
+;;
+;; Redistribution and use in source and binary forms, with or without
+;; modification, are permitted provided that the following conditions are met:
+;;
+;; 1. Redistributions of source code must retain the above copyright notice, this
+;;    list of conditions and the following disclaimer.
+;;
+;; 2. Redistributions in binary form must reproduce the above copyright notice,
+;;    this list of conditions and the following disclaimer in the documentation
+;;    and/or other materials provided with the distribution.
+;;
+;; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+;; ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+;; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+;; DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+;; FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+;; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+;; SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+;; CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+;; OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+;; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+(defmacro with-hash-iter ((name hash-form : key val) . body)
+  (let ((hash (gensym))
+        (iter (gensym))
+        (next (gensym)))
+    ^(let* ((,hash ,hash-form)
+            (,iter (hash-begin ,hash))
+            ,*(if key ^((,key)))
+            ,*(if val ^((,val))))
+       (flet ((,name ()
+                ,(if (not (or key val))
+                   ^(hash-next ,iter)
+                   ^(let ((,next (hash-next ,iter)))
+                      ,*(if key ^((set ,key (car ,next))))
+                      ,*(if val ^((set ,val (cdr ,next))))
+                      ,next))))
+         ,*body))))