diff --git a/msi.gama.core/src/msi/gaml/types/GamaPairType.java b/msi.gama.core/src/msi/gaml/types/GamaPairType.java
index ad4dd57ccc..a98a67c0ec 100644
--- a/msi.gama.core/src/msi/gaml/types/GamaPairType.java
+++ b/msi.gama.core/src/msi/gaml/types/GamaPairType.java
@@ -1,12 +1,12 @@
 /*******************************************************************************************************
  *
- * GamaPairType.java, in msi.gama.core, is part of the source code of the
- * GAMA modeling and simulation platform (v.1.9.2).
+ * GamaPairType.java, in msi.gama.core, is part of the source code of the GAMA modeling and simulation platform
+ * (v.1.9.2).
  *
  * (c) 2007-2023 UMI 209 UMMISCO IRD/SU & Partners (IRIT, MIAT, TLU, CTU)
  *
  * Visit https://github.com/gama-platform/gama for license information and contacts.
- * 
+ *
  ********************************************************************************************************/
 package msi.gaml.types;
 
@@ -21,8 +21,8 @@
 import msi.gama.runtime.exceptions.GamaRuntimeException;
 import msi.gama.util.GamaListFactory;
 import msi.gama.util.GamaPair;
-import msi.gama.util.IList;
 import msi.gama.util.IMap;
+import msi.gaml.expressions.IExpression;
 
 /**
  * Written by drogoul Modified on 1 ao�t 2010
@@ -47,20 +47,24 @@ public GamaPair cast(final IScope scope, final Object obj, final Object param, f
 	}
 
 	@Override
-	public int getNumberOfParameters() {
-		return 2;
-	}
+	public int getNumberOfParameters() { return 2; }
 
 	/**
 	 * Static cast.
 	 *
-	 * @param scope the scope
-	 * @param obj the obj
-	 * @param keyType the key type
-	 * @param contentsType the contents type
-	 * @param copy the copy
+	 * @param scope
+	 *            the scope
+	 * @param obj
+	 *            the obj
+	 * @param keyType
+	 *            the key type
+	 * @param contentsType
+	 *            the contents type
+	 * @param copy
+	 *            the copy
 	 * @return the gama pair
-	 * @throws GamaRuntimeException the gama runtime exception
+	 * @throws GamaRuntimeException
+	 *             the gama runtime exception
 	 */
 	public static GamaPair staticCast(final IScope scope, final Object obj, final IType keyType,
 			final IType contentsType, final boolean copy) throws GamaRuntimeException {
@@ -70,40 +74,16 @@ public static GamaPair staticCast(final IScope scope, final Object obj, final IT
 			value = ((GamaPair) obj).value;
 		} else
 		// 8/01/14: No more automatic casting between points and pairs (as
-		// points can now have 3 coordinates
-		// if ( obj instanceof GamaPoint ) { return new GamaPair(((GamaPoint)
-		// obj).x, ((GamaPoint) obj).y); }
+		// points can have 3 coordinates)
 		if (obj instanceof GamaShape && ((GamaShape) obj).getInnerGeometry() instanceof DynamicLineString) {
 			final DynamicLineString g = (DynamicLineString) ((GamaShape) obj).getInnerGeometry();
 			key = g.getSource();
 			value = g.getTarget();
-		} else if (obj instanceof IMap) {
-			final IMap m = (IMap) obj;
+		} else if (obj instanceof IMap m) {
 			key = GamaListFactory.create(scope, m.getGamlType().getKeyType(), m.keySet());
 			value = GamaListFactory.create(scope, m.getGamlType().getContentType(), m.values());
-		} else if (obj instanceof IList) {
-			final IList l = (IList) obj;
-			switch (l.size()) {
-				case 0:
-					key = null;
-					value = null;
-					break;
-				case 1:
-					key = l.get(0);
-					value = l.get(0);
-					break;
-				case 2:
-					key = l.get(0);
-					value = l.get(1);
-					break;
-				default:
-					key = l;
-					value = l;
-			}
-
 		} else {
-			// 8/01/14 : Change of behavior for the default pair: now returns a
-			// pair object::object
+			// 8/01/14 : Change of behavior: now returns a pair object::object
 			key = obj;
 			value = obj;
 		}
@@ -113,23 +93,39 @@ public static GamaPair staticCast(final IScope scope, final Object obj, final IT
 	}
 
 	@Override
-	public GamaPair getDefault() {
-		return new GamaPair(null, null, Types.NO_TYPE, Types.NO_TYPE);
+	public IType keyTypeIfCasting(final IExpression exp) {
+		final IType itemType = exp.getGamlType();
+		switch (itemType.id()) {
+			case PAIR:
+				return itemType.getKeyType();
+			case MAP:
+				return Types.LIST.of(itemType.getKeyType());
+		}
+		return itemType;
 	}
 
 	@Override
-	public IType getContentType() {
-		return Types.get(NONE);
+	public IType contentsTypeIfCasting(final IExpression exp) {
+		final IType itemType = exp.getGamlType();
+		switch (itemType.id()) {
+			case MAP:
+				return Types.LIST.of(itemType.getContentType());
+			case PAIR:
+				return itemType.getContentType();
+
+		}
+		return itemType;
 	}
 
+	@Override
+	public GamaPair getDefault() { return new GamaPair(null, null, Types.NO_TYPE, Types.NO_TYPE); }
+
+	@Override
+	public IType getContentType() { return Types.get(NONE); }
+
 	@Override
 	public boolean canCastToConst() {
 		return true;
 	}
-	//
-	// @Override
-	// public boolean hasContents() {
-	// return true;
-	// }
 
 }