From c02c40f93e027c63b9ba97756247b58c8e3e5a46 Mon Sep 17 00:00:00 2001
From: Danny Yoo <dyoo@cs.wpi.edu>
Date: Mon, 7 Nov 2011 19:02:07 -0500
Subject: [PATCH] hash-copy

---
 compiler/kernel-primitives.rkt                 | 1 +
 js-assembler/runtime-src/baselib-hashes.js     | 4 ++++
 js-assembler/runtime-src/baselib-primitives.js | 7 +++++++
 lang/kernel.rkt                                | 1 +
 tests/more-tests/hashes.expected               | 3 +++
 tests/more-tests/hashes.rkt                    | 7 +++++++
 6 files changed, 23 insertions(+)

diff --git a/compiler/kernel-primitives.rkt b/compiler/kernel-primitives.rkt
index ecd1216..e0108d9 100644
--- a/compiler/kernel-primitives.rkt
+++ b/compiler/kernel-primitives.rkt
@@ -101,6 +101,7 @@
                                     'make-immutable-hash
                                     'make-immutable-hasheqv
                                     'make-immutable-hasheq
+                                    'hash-copy
                                     'hash-ref
                                     'hash-has-key?
                                     'hash-set!
diff --git a/js-assembler/runtime-src/baselib-hashes.js b/js-assembler/runtime-src/baselib-hashes.js
index 19e9371..f27ed45 100644
--- a/js-assembler/runtime-src/baselib-hashes.js
+++ b/js-assembler/runtime-src/baselib-hashes.js
@@ -133,6 +133,10 @@
         this.hash = hash;
     };
 
+    WhalesongHashtable.prototype.clone = function() {
+        return new WhalesongHashtable(this.type, this.hash_function, this.equality_function, this.hash.clone());
+    };
+
     WhalesongHashtable.prototype.toWrittenString = function (cache) {
         var keys = this.hash.keys();
         var ret = [], i;
diff --git a/js-assembler/runtime-src/baselib-primitives.js b/js-assembler/runtime-src/baselib-primitives.js
index 4c51476..be66450 100644
--- a/js-assembler/runtime-src/baselib-primitives.js
+++ b/js-assembler/runtime-src/baselib-primitives.js
@@ -2571,6 +2571,13 @@
             return initializeHash(lst, plt.baselib.hashes.makeEqualHashtable());
         });
 
+    installPrimitiveProcedure(
+        'hash-copy',
+        1,
+        function(M) {
+            var hash = checkMutableHash(M, 'hash-copy', 0);
+            return hash.clone();
+        });
 
     installPrimitiveProcedure(
         'hash',
diff --git a/lang/kernel.rkt b/lang/kernel.rkt
index 334ecff..e77487d 100644
--- a/lang/kernel.rkt
+++ b/lang/kernel.rkt
@@ -161,6 +161,7 @@
          make-immutable-hash
          make-immutable-hasheqv
          make-immutable-hasheq
+         hash-copy
          hash-ref
          hash-set!
          hash-set
diff --git a/tests/more-tests/hashes.expected b/tests/more-tests/hashes.expected
index 98e9c68..e785b29 100644
--- a/tests/more-tests/hashes.expected
+++ b/tests/more-tests/hashes.expected
@@ -52,3 +52,6 @@ true
 #hash((1 . one) (2 . two))
 #hasheqv((1 . one) (2 . two))
 #hasheq((1 . one) (2 . two))
+
+A
+alphabet
diff --git a/tests/more-tests/hashes.rkt b/tests/more-tests/hashes.rkt
index 2ca21e5..b7ac7d8 100644
--- a/tests/more-tests/hashes.rkt
+++ b/tests/more-tests/hashes.rkt
@@ -125,3 +125,10 @@
 (hasheqv 1 'one 2 'two)
 (hasheq 1 'one 2 'two)
 
+
+(newline)
+(let* ([h1 (make-hash '((a . "A")))]
+       [h2 (hash-copy h1)])
+  (hash-set! h2 'a "alphabet")
+  (displayln (hash-ref h1 'a))
+  (displayln (hash-ref h2 'a)))