From a8ba8af211e985a12c9b140f3928fe823ab8544f Mon Sep 17 00:00:00 2001
From: paulklint <Paul.Klint@cwi.nl>
Date: Sun, 29 Sep 2024 14:46:00 +0200
Subject: [PATCH] Take care of type parameters in field update

---
 .../rascalcore/check/CollectExpression.rsc    | 22 ++++++++++++++++--
 .../lang/rascalcore/compile/Examples/Tst4.rsc | 23 +++++++++++--------
 2 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/src/org/rascalmpl/core/library/lang/rascalcore/check/CollectExpression.rsc b/src/org/rascalmpl/core/library/lang/rascalcore/check/CollectExpression.rsc
index 4e70ac3a..b30ad8b9 100644
--- a/src/org/rascalmpl/core/library/lang/rascalcore/check/CollectExpression.rsc
+++ b/src/org/rascalmpl/core/library/lang/rascalcore/check/CollectExpression.rsc
@@ -1053,8 +1053,26 @@ void collect(current:(Expression) `<Expression expression> [ <Name field> = <Exp
     //c.use(field, {fieldId(), keywordFieldId()});
     c.calculate("field update of `<field>`", current, [expression, repl],
         AType(Solver s){ 
-                 fieldType = computeFieldTypeWithADT(s.getType(expression), field, scope, s);
-                 replType = s.getType(repl);
+                fieldType = computeFieldTypeWithADT(s.getType(expression), field, scope, s);
+                replType = s.getType(repl);
+
+                bindings = ();
+                try   bindings = unifyRascalTypeParams(fieldType, replType, bindings);
+                catch invalidMatch(str reason):
+                    s.report(error(current, reason));
+                
+                if(!isEmpty(bindings)){
+                    try {
+                        fieldType = instantiateRascalTypeParameters(field, fieldType, bindings, s);
+                    } catch invalidInstantiation(str msg): {
+                        s.report(error(current, "Cannot instantiate lhs type `<prettyAType(fieldType)>` of assignment: " + msg));
+                    }
+                    try {
+                        replType = instantiateRascalTypeParameters(current, replType, bindings, s);
+                    } catch invalidInstantiation(str msg): {
+                        s.report(error(current, "Cannot instantiate rhs type `<prettyAType(replype)>` of assignment: " + msg));
+                    }
+                   }        
                  checkNonVoid(expression, s, "Base expression of field update`");
                  checkNonVoid(repl, s, "Replacement expression of field update`");
                  s.requireSubType(replType, fieldType, error(current, "Cannot assign value of type %t to field %q of type %t", replType, field, fieldType));
diff --git a/src/org/rascalmpl/core/library/lang/rascalcore/compile/Examples/Tst4.rsc b/src/org/rascalmpl/core/library/lang/rascalcore/compile/Examples/Tst4.rsc
index e5f069f3..abde37ca 100644
--- a/src/org/rascalmpl/core/library/lang/rascalcore/compile/Examples/Tst4.rsc
+++ b/src/org/rascalmpl/core/library/lang/rascalcore/compile/Examples/Tst4.rsc
@@ -1,15 +1,20 @@
 module lang::rascalcore::compile::Examples::Tst4
 
-lrel[str, int, str] main(){
-    lrel[str, int] X = [<"a", 1>];
-    lrel[str, int] Y = [<"a", 1>];
-
-    lrel[str,int,int] XP = X<0,1, 1>;
-    lrel[int, str] YP = Y<1,0>;
-    Z = XP o YP;
-    return Z;
-    //return {};
+//lrel[str, int, str] main(){
+//    lrel[str, int] X = [<"a", 1>];
+//    lrel[str, int] Y = [<"a", 1>];
+//
+//    lrel[str,int,int] XP = X<0,1, 1>;
+//    lrel[int, str] YP = Y<1,0>;
+//    Z = XP o YP;
+//    return Z;
+//}
+value main(){
+    rel[value, tuple[int, value]] X = {<0,<1,1>>} ;
+    rel[tuple[value,int], int] Y = {<<1,1>,2>};
+    return X o Y;
 }
+//Met bijv: {<0,<1,1>>} o {<<1,1>,2>} als voorbeeld dat dit oplevert {<0,2>} .
 
 //data Face = top() | left() | right() | bottom();
 //