From 435a89a71dee03646b52b312731f2803be5b5b57 Mon Sep 17 00:00:00 2001
From: ike709 <ike709@github.com>
Date: Tue, 11 Feb 2025 01:53:43 -0600
Subject: [PATCH] Implement `values_dot()`

---
 .../DMProject/Tests/Builtins/values_dot.dm    |  5 ++++
 DMCompiler/DMStandard/_Standard.dm            |  1 +
 .../Procs/Native/DreamProcNative.cs           |  1 +
 .../Procs/Native/DreamProcNativeRoot.cs       | 29 +++++++++++++++++++
 4 files changed, 36 insertions(+)
 create mode 100644 Content.Tests/DMProject/Tests/Builtins/values_dot.dm

diff --git a/Content.Tests/DMProject/Tests/Builtins/values_dot.dm b/Content.Tests/DMProject/Tests/Builtins/values_dot.dm
new file mode 100644
index 0000000000..8d78f0a188
--- /dev/null
+++ b/Content.Tests/DMProject/Tests/Builtins/values_dot.dm
@@ -0,0 +1,5 @@
+
+/proc/RunTest()
+	ASSERT(values_dot(list(a=2.4,b=1,c=7),list(a=2,b=4,c=null)) == 8.8)
+	ASSERT(values_dot(list(),list(a=2,b=4)) == 0)
+	ASSERT(values_dot(list("a"),list(a=2,b=4)) == 0)
\ No newline at end of file
diff --git a/DMCompiler/DMStandard/_Standard.dm b/DMCompiler/DMStandard/_Standard.dm
index 45effa8b85..2b4c887090 100644
--- a/DMCompiler/DMStandard/_Standard.dm
+++ b/DMCompiler/DMStandard/_Standard.dm
@@ -107,6 +107,7 @@ proc/typesof(Item1) as /list
 proc/uppertext(T as text) as text
 proc/url_decode(UrlText) as text
 proc/url_encode(PlainText, format = 0) as text
+proc/values_dot(A, B) as num
 proc/values_product(Alist) as num
 proc/values_sum(Alist) as num
 proc/view(Dist = 5, Center = usr) as /list
diff --git a/OpenDreamRuntime/Procs/Native/DreamProcNative.cs b/OpenDreamRuntime/Procs/Native/DreamProcNative.cs
index 431d72d79e..a10346476e 100644
--- a/OpenDreamRuntime/Procs/Native/DreamProcNative.cs
+++ b/OpenDreamRuntime/Procs/Native/DreamProcNative.cs
@@ -108,6 +108,7 @@ public static void SetupNativeProcs(DreamObjectTree objectTree) {
         objectTree.SetGlobalNativeProc(DreamProcNativeRoot.NativeProc_uppertext);
         objectTree.SetGlobalNativeProc(DreamProcNativeRoot.NativeProc_url_decode);
         objectTree.SetGlobalNativeProc(DreamProcNativeRoot.NativeProc_url_encode);
+        objectTree.SetGlobalNativeProc(DreamProcNativeRoot.NativeProc_values_dot);
         objectTree.SetGlobalNativeProc(DreamProcNativeRoot.NativeProc_values_product);
         objectTree.SetGlobalNativeProc(DreamProcNativeRoot.NativeProc_values_sum);
         objectTree.SetGlobalNativeProc(DreamProcNativeRoot.NativeProc_view);
diff --git a/OpenDreamRuntime/Procs/Native/DreamProcNativeRoot.cs b/OpenDreamRuntime/Procs/Native/DreamProcNativeRoot.cs
index b9a1ed7630..e2b4e0a586 100644
--- a/OpenDreamRuntime/Procs/Native/DreamProcNativeRoot.cs
+++ b/OpenDreamRuntime/Procs/Native/DreamProcNativeRoot.cs
@@ -3108,6 +3108,35 @@ public static DreamValue NativeProc_url_encode(NativeProc.Bundle bundle, DreamOb
         return new DreamValue(HttpUtility.UrlEncode(plainText));
     }
 
+    [DreamProc("values_dot")]
+    [DreamProcParameter("A", Type = DreamValueTypeFlag.DreamObject)]
+    [DreamProcParameter("B", Type = DreamValueTypeFlag.DreamObject)]
+    public static DreamValue NativeProc_values_dot(NativeProc.Bundle bundle, DreamObject? src, DreamObject? usr) {
+        if (bundle.Arguments.Length != 2) throw new Exception("expected 2 arguments");
+
+        DreamValue argA = bundle.GetArgument(0, "A");
+        DreamValue argB = bundle.GetArgument(1, "B");
+
+        float sum = 0; // Default return is 0 for invalid args
+
+        if (argA.TryGetValueAsDreamList(out var listA) && listA.IsAssociative && argB.TryGetValueAsDreamList(out var listB) && listB.IsAssociative) {
+            var aValues = listA.GetAssociativeValues();
+            var bValues = listB.GetAssociativeValues();
+
+            // sum += valueA * valueB
+            // for each assoc value whose key exists in both lists
+            // and when both assoc values are floats
+            foreach (var (key,value) in aValues) {
+                if (value.TryGetValueAsFloat(out var aFloat) && bValues.TryGetValue(key, out var bVal) &&
+                    bVal.TryGetValueAsFloat(out var bFloat)) {
+                    sum += (aFloat * bFloat);
+                }
+            }
+        }
+
+        return new DreamValue(sum);
+    }
+
     [DreamProc("values_product")]
     [DreamProcParameter("Alist", Type = DreamValueTypeFlag.DreamObject)]
     public static DreamValue NativeProc_values_product(NativeProc.Bundle bundle, DreamObject? src, DreamObject? usr) {