Minor code simplification / cleanup

Author: stanhebben

CodeModel/src/main/java/org/openzen/zenscript/codemodel/compilation/CastedEval.java

@@ -61,12 +61,15 @@ public CastedExpression of(Expression value) {
 
 		Optional<Expression> implicitCast = resolvedValueType.tryCastImplicit(type, compiler, position, value, optional);
 		if (implicitCast.isPresent())
-			return new CastedExpression(CastedExpression.Level.IMPLICIT, implicitCast.get());
+			return CastedExpression.implicit(implicitCast.get());
 
-		if (value.type.canCastImplicitTo(type))
-			return new CastedExpression(CastedExpression.Level.IMPLICIT, value.type.castImplicitTo(position, value, type));
-		if (type.canCastImplicitFrom(value.type))
-			return CastedExpression.implicit(type.castImplicitFrom(position, value));
+		Optional<Expression> castedImplicitlyTo = value.type.castImplicitTo(position, value, type);
+		if (castedImplicitlyTo.isPresent())
+			return CastedExpression.implicit(castedImplicitlyTo.get());
+
+		Optional<Expression> castedImplicitlyFrom = type.castImplicitFrom(position, value);
+		if (castedImplicitlyFrom.isPresent())
+			return CastedExpression.implicit(castedImplicitlyFrom.get());
 
 		if (value.type == BasicTypeID.NULL && type.isOptional())
 			return CastedExpression.exact(new NullExpression(position, type));

CodeModel/src/main/java/org/openzen/zenscript/codemodel/type/TypeID.java

@@ -94,36 +94,12 @@ default InvalidTypeID asInvalid() {
 		return new InvalidTypeID(CodePosition.UNKNOWN, CompileErrors.invalidType());
 	}
 
-	default boolean canCastImplicitTo(TypeID other) {
-		return false;
-	}
-
-	default boolean canCastExplicitTo(TypeID other) {
-		return false;
-	}
-
-	default boolean canCastImplicitFrom(TypeID other) {
-		return false;
-	}
-
-	default boolean canCastExplicitFrom(TypeID other) {
-		return false;
-	}
-
-	default Expression castImplicitTo(CodePosition position, Expression value, TypeID toType) {
-		return null;
-	}
-
-	default Expression castExplicitTo(CodePosition position, Expression value, TypeID toOther) {
-		return null;
-	}
-
-	default Expression castImplicitFrom(CodePosition position, Expression value) {
-		return null;
+	default Optional<Expression> castImplicitTo(CodePosition position, Expression value, TypeID toType) {
+		return Optional.empty();
 	}
 
-	default Expression castExplicitFrom(CodePosition position, Expression value) {
-		return null;
+	default Optional<Expression> castImplicitFrom(CodePosition position, Expression value) {
+		return Optional.empty();
 	}
 
 	default Optional<OptionalTypeID> asOptional() {

JavaShared/src/main/java/org/openzen/zenscript/javashared/types/JavaFunctionalInterfaceTypeID.java

@@ -10,6 +10,7 @@
 import org.openzen.zenscript.javashared.expressions.JavaFunctionInterfaceCastExpression;
 
 import java.lang.reflect.Method;
+import java.util.Optional;
 
 public class JavaFunctionalInterfaceTypeID extends FunctionTypeID {
 	public final Method functionalInterfaceMethod;
@@ -28,32 +29,23 @@ public TypeID instance(GenericMapper mapper) {
 	}
 
 	@Override
-	public boolean canCastImplicitTo(TypeID other) {
-		return other instanceof FunctionTypeID && ((FunctionTypeID) other).header.isEquivalentTo(header);
-	}
-
-	@Override
-	public boolean canCastImplicitFrom(TypeID other) {
-		return other instanceof FunctionTypeID && ((FunctionTypeID) other).header.isEquivalentTo(header);
-	}
-
-	@Override
-	public Expression castImplicitTo(CodePosition position, Expression value, TypeID other) {
+	public Optional<Expression> castImplicitTo(CodePosition position, Expression value, TypeID other) {
 		if (other instanceof FunctionTypeID) {
 			FunctionTypeID otherType = (FunctionTypeID) other;
 			if (header.isEquivalentTo(otherType.header))
-				return new JavaFunctionInterfaceCastExpression(position, otherType, value);
+				return Optional.of(new JavaFunctionInterfaceCastExpression(position, otherType, value));
 		}
-		return null;
+
+		return Optional.empty();
 	}
 
 	@Override
-	public Expression castImplicitFrom(CodePosition position, Expression value) {
+	public Optional<Expression> castImplicitFrom(CodePosition position, Expression value) {
 		if (value.type instanceof FunctionTypeID) {
 			FunctionTypeID otherType = (FunctionTypeID) value.type;
 			if (header.isEquivalentTo(otherType.header))
-				return new JavaFunctionInterfaceCastExpression(position, this, value);
+				return Optional.of(new JavaFunctionInterfaceCastExpression(position, this, value));
 		}
-		return null;
+		return Optional.empty();
 	}
 }