Just found out i have to rewrite the entire thing due to compilation errors :'3

Now Duplicated Custom Class declaration will be ignored and prints a warning message.

extraParams.hxml

@@ -1,3 +1,4 @@
 --macro keep('IntIterator')
 --macro hscript.macros.AbstractHandler.init()
 --macro hscript.macros.ClassExtendMacro.init()
+--macro hscript.macros.CustomClassMacro.init()

hscript/Interp.hx

@@ -122,7 +122,8 @@ class Interp {
 		return inCustomClass ? cast scriptObject : null;
 
 	public var errorHandler:Error->Void;
-	public var importFailedCallback:Array<String>->Bool;
+	public var warnHandler:Error->Void;
+	public var importFailedCallback:Array<String>->Null<String>->Bool;
 
 	public var customClasses:Map<String, CustomClassHandler>;
 	public var variables:Map<String, Dynamic>;
@@ -143,6 +144,7 @@ class Interp {
 	var beforeAlias:Null<String> = null;
 
 	public var importEnabled:Bool = true;
+	public var allowStaticImports:Bool = true;
 
 	public var allowStaticVariables:Bool = false;
 	public var allowPublicVariables:Bool = false;
@@ -602,6 +604,15 @@ class Interp {
 		return null;
 	}
 
+	public inline function warn(e:#if hscriptPos ErrorDef #else Error #end) {
+		#if hscriptPos var e = new Error(e, curExpr.pmin, curExpr.pmax, curExpr.origin, curExpr.line); #end
+		
+		if(warnHandler != null)
+			warnHandler(e);
+		else
+			trace('[ Warning ] ${Printer.errorToString(e)}');
+	}
+
 	inline function rethrow(e:Dynamic):Void {
 		#if hl
 		hl.Api.rethrow(e);
@@ -705,12 +716,15 @@ class Interp {
 		switch (e) {
 			case EPackage(_):
 			case EClass(name, fields, extend, interfaces, isFinal):
+				// TODO: module isolation
 				var oldName:String = name;
 				var hasAlias:Bool = (setAlias != null && beforeAlias == oldName);
 				var toSetName:String = hasAlias ? setAlias : oldName;
 
-				if (customClasses.exists(toSetName))
-					error(EAlreadyExistingClass(toSetName));
+				if (customClasses.exists(toSetName)) {
+					warn(EAlreadyExistingClass(toSetName));
+					return null;// ignore it
+				}
 
 				inline function importVar(thing:String):String {
 					if (thing == null)
@@ -725,20 +739,20 @@ class Interp {
 					beforeAlias = null;
 					setAlias = null;
 				}
-			case EImport(c, n, isUsing):
-				if (!importEnabled)
-					return null;
-				var splitClassName = [for (e in c.split(".")) e.trim()];
+			case EImport(clsName, aliasAs, isUsing):
+				if(!importEnabled) return null;
+
+				var splitClassName = [for (e in clsName.split(".")) e.trim()];
 				var realClassName = splitClassName.join(".");
 				var claVarName = splitClassName[splitClassName.length - 1];
-				var toSetName = n != null ? n : claVarName;
+				var toSetName = aliasAs != null ? aliasAs : claVarName;
 				var oldClassName = realClassName;
 				var oldSplitName = splitClassName.copy();
 
-				if (variables.exists(toSetName)) { // class is already imported 
+				if(variables.exists(toSetName)) { // class is already imported 
 					if(isUsing && !usingHandler.entryExists(toSetName))
 						setUsing(toSetName, variables.get(toSetName)); 
-					
+
 					return null;
 				}
 
@@ -748,56 +762,70 @@ class Interp {
 					// setting the extension
 					if(isUsing && !usingHandler.entryExists(toSetName))
 						setCustomClassUsing(toSetName, customClasses.get(toSetName));
+
 					return null;
 				}
+				
+				function importResolve(__clsName:String):Null<Dynamic> {
+					var _realClassName = getLocalImportRedirect(__clsName);
+					if(importBlocklist.contains(_realClassName)) return null;
 
-				var realClassName = getLocalImportRedirect(realClassName);
-
-				if (importBlocklist.contains(realClassName))
-					return null;
-				var cl = Type.resolveClass(realClassName);
-				if (cl == null)
-					cl = Type.resolveClass('${realClassName}_HSC');
+					var _cl = Type.resolveClass(_realClassName);
+					if(_cl == null) _cl = Type.resolveClass('${_realClassName}_HSC');
+					return _cl;
+				}
 
+				var cl = importResolve(realClassName);
 				var en = Type.resolveEnum(realClassName);
-
 				//trace(realClassName, cl, en, splitClassName);
 
 				// Allow for flixel.ui.FlxBar.FlxBarFillDirection;
-				if (cl == null && en == null) {
+				if(cl == null && en == null) {
 					if(splitClassName.length > 1) {
 						splitClassName.splice(-2, 1); // Remove the last last item
 						realClassName = splitClassName.join(".");
 
-						var realClassName = getLocalImportRedirect(realClassName);
-
-						if (importBlocklist.contains(realClassName))
-							return null;
-
-						cl = Type.resolveClass(realClassName);
-						if (cl == null)
-							cl = Type.resolveClass('${realClassName}_HSC');
-
+						cl = importResolve(realClassName);
 						en = Type.resolveEnum(realClassName);
-
 						//trace(realClassName, cl, en, splitClassName);
 					}
 				}
 
-				if (cl == null && en == null) {
+				if(cl == null && en == null) {
+					if(allowStaticImports) { //allows for static imports like "haxe.io.Path.normalize"
+						var clPth = oldSplitName.copy();
+						var funcName = clPth.pop();
+						var statField = Reflect.getProperty(Type.resolveClass(StringTools.trim(clPth.join("."))), funcName);
+
+						if(statField != null) {
+							variables.set((toSetName != null && toSetName.length > 0 ? toSetName : funcName), statField);
+							return null;
+						}
+					}
+
 					beforeAlias = claVarName;
-					setAlias = n;
-					if (importFailedCallback == null || !importFailedCallback(oldSplitName)){
+					setAlias = aliasAs;
+					if(importFailedCallback == null || !importFailedCallback(oldSplitName, toSetName)){
 						beforeAlias = null;
 						setAlias = null;
 						error(EInvalidClass(oldClassName));
-					}	
+					}
 				} else {
-					if (en != null) {
-						if(isUsing) error(EInvalidClass(oldClassName));
-						// ENUM!!!!
+					//If the first letter of the alias is not an uppercase letter, then throw an error.
+					//We don't need to worry about this for static imports.
+					if(toSetName != claVarName && !Tools.isUppercase(toSetName)) {
+						error(ECustom("Type aliases must start with an uppercase letter"));
+						return null;
+					}
+
+					if(en != null) { // ENUM!!!!
+						if(isUsing) {
+							error(EInvalidClass(oldClassName));
+							return null;
+						}
+
 						var enumThingy:HEnum = {};
-						for (c in en.getConstructors()) {
+						for(c in en.getConstructors()) {
 							try {
 								//UnsafeReflect.setField(enumThingy, c, en.createByName(c));
 								enumThingy.setEnum(c, en.createByName(c));
@@ -811,12 +839,11 @@ class Interp {
 							}
 						}
 						variables.set(toSetName, enumThingy);
-					} else {
+					} else { //Standard class
 						if(isUsing) setUsing(toSetName, cl);
 						variables.set(toSetName, cl);
 					}
 				}
-
 				return null;
 
 			case EEnum(en, _): // TODO: enum abstracts
@@ -1222,7 +1249,7 @@ class Interp {
 				var match = false;
 				for (c in cases) {
 					for (v in c.values) {
-						// https://github.com/FunkinCrew/hscript/blob/funkin-dev/hscript/Interp.hx#L531
+						// https://github.com/FunkinCrew/hscript/blob/funkin-dev/hscript/Interp.hx#L611
 						switch (Tools.expr(v)) {
 							case ECall(e, params):
 								switch (Tools.expr(e)) {
@@ -1626,3 +1653,5 @@ class Interp {
 			return Type.createInstance(c, args);
 	}
 }
+
+

hscript/Tools.hx

@@ -131,6 +131,13 @@ class Tools {
 		#end
 	}
 
+	public static function isUppercase(s:String) {
+		if(s.length == 0) return false;
+		var c:Int = StringTools.fastCodeAt(s, 0);
+		if(StringTools.isEof(c)) return false; // Just in case :3
+		return c >= 65 && c <= 90; // A-Z
+	}
+
 	public static inline function isCustomAbstract(obj:Dynamic):Bool
 		return obj != null && obj is IHScriptAbstractBehaviour;
 

hscript/macros/ClassExtendMacro.hx

@@ -26,9 +26,11 @@ class ClassExtendMacro {
 		#if !display
 		#if CUSTOM_CLASSES
 		if(Context.defined("display")) return;
+		/*
 		for(apply in Config.ALLOWED_CUSTOM_CLASSES) {
 			Compiler.addGlobalMetadata(apply, "@:build(hscript.macros.ClassExtendMacro.build())");
 		}
+		*/
 		//Context.onAfterTyping(buildTyped);
 		#end
 		#end