Language experiments (#2068)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Moved to experiments.
Added some more tests.

* More tests around associated types.

* Return interface tests.

* More tests.

1 files changed, 59 insertions, 0 deletions

diff --git a/tests/experiments/interface/associated-type.slang b/tests/experiments/interface/associated-type.slang
new file mode 100644
index 000000000..2cc4f7c68
--- /dev/null
+++ b/tests/experiments/interface/associated-type.slang
@@ -0,0 +1,59 @@
+//TEST_TEST:SIMPLE:-target dxil -entry computeMain -profile cs_6_2
+
+/* 
+Testing how an associated type can be used.
+
+In this example because we get the Type from the interface, it doesn't know what actual type it is.
+
+.slang(43): error 30027: 'getValue' is not a member of 'Type'.
+    outputBuffer[dispatchThreadID.x] = x + r.getValue(x);
+
+From an error message point of view this perhaps somewhat confusing because there aren't any methods on Type in this context. 
+
+It would be possible for an implementation to determine intf is impl, and do the right thing, although not in general. 
+*/
+
+struct SomeType
+{
+    int getValue(int index) { return index + offset; }
+    
+    int offset;
+};
+
+interface IInterface
+{
+    associatedtype Type;
+    
+    Type get(int offset);
+};
+
+struct InterfaceImpl : IInterface
+{
+    typedef SomeType Type;
+    
+    Type get(int offset) 
+    {
+        Type v;
+        v.offset = offset;
+        return v;
+    }; 
+};
+
+RWStructuredBuffer<int> outputBuffer;
+
+[numthreads(4, 4, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int x = dispatchThreadID.x;
+    
+    InterfaceImpl impl;
+    
+    IInterface intf = impl;
+    
+    // Works if we get from impl. Doesn't work if we get from the interface
+    // saying that 'Type' doesn't define getValue.
+    
+    var r = intf.get(16);
+    
+    outputBuffer[dispatchThreadID.x] = x + r.getValue(x);
+}
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