diff --git a/lib/core.ts b/lib/core.ts
index 3ce7a25..fa09628 100644
--- a/lib/core.ts
+++ b/lib/core.ts
@@ -17,7 +17,8 @@ interface Internals {
     syntax: SyntaxErrorConstructor;
     type: TypeErrorConstructor;
     range: RangeErrorConstructor;
-
+    
+    regexp: typeof RegExp;
     map: typeof Map;
     set: typeof Set;
 
@@ -50,44 +51,51 @@ interface Internals {
     log(...args: any[]): void;
 }
 
+var env: Environment = arguments[0], internals: Internals = arguments[1];
+
 try {
-    var env: Environment = arguments[0], internals: Internals = arguments[1];
 
-    const Object = env.global.Object = internals.object;
-    const Function = env.global.Function = internals.function;
-    const Array = env.global.Array = internals.array;
-    const Promise = env.global.Promise = internals.promise;
-    const Boolean = env.global.Boolean = internals.bool;
-    const Number = env.global.Number = internals.number;
-    const String = env.global.String = internals.string;
-    const Symbol = env.global.Symbol = internals.symbol;
-    const Error = env.global.Error = internals.error;
-    const SyntaxError = env.global.SyntaxError = internals.syntax;
-    const TypeError = env.global.TypeError = internals.type;
-    const RangeError = env.global.RangeError = internals.range;
+    const values = {
+        Object: env.global.Object = internals.object,
+        Function: env.global.Function = internals.function,
+        Array: env.global.Array = internals.array,
+        Promise: env.global.Promise = internals.promise,
+        Boolean: env.global.Boolean = internals.bool,
+        Number: env.global.Number = internals.number,
+        String: env.global.String = internals.string,
+        Symbol: env.global.Symbol = internals.symbol,
+        Error: env.global.Error = internals.error,
+        SyntaxError: env.global.SyntaxError = internals.syntax,
+        TypeError: env.global.TypeError = internals.type,
+        RangeError: env.global.RangeError = internals.range,
+        RegExp: env.global.RegExp = internals.regexp,
+        Map: env.global.Map = internals.map,
+        Set: env.global.Set = internals.set,
+    }
+    const Array = values.Array;
 
-    const Map = env.global.Map = internals.map;
-    const Set = env.global.Set = internals.set;
+    env.setProto('object', env.global.Object.prototype);
+    env.setProto('function', env.global.Function.prototype);
+    env.setProto('array', env.global.Array.prototype);
+    env.setProto('number', env.global.Number.prototype);
+    env.setProto('string', env.global.String.prototype);
+    env.setProto('symbol', env.global.Symbol.prototype);
+    env.setProto('bool', env.global.Boolean.prototype);
 
-    env.setProto('object', Object.prototype);
-    env.setProto('function', Function.prototype);
-    env.setProto('array', Array.prototype);
-    env.setProto('number', Number.prototype);
-    env.setProto('string', String.prototype);
-    env.setProto('symbol', Symbol.prototype);
-    env.setProto('bool', Boolean.prototype);
-
-    env.setProto('error', Error.prototype);
-    env.setProto('rangeErr', RangeError.prototype);
-    env.setProto('typeErr', TypeError.prototype);
-    env.setProto('syntaxErr', SyntaxError.prototype);
-
-    (Object.prototype as any).__proto__ = null;
+    env.setProto('error', env.global.Error.prototype);
+    env.setProto('rangeErr', env.global.RangeError.prototype);
+    env.setProto('typeErr', env.global.TypeError.prototype);
+    env.setProto('syntaxErr', env.global.SyntaxError.prototype);
+    (env.global.Object.prototype as any).__proto__ = null;
 
     internals.getEnv(run)?.setProto('array', Array.prototype);
     globalThis.log = (...args) => internals.apply(internals.log, internals, args);
 
-    run('regex');
+    for (const key in values) {
+        (values as any)[key].prototype[env.symbol('Symbol.typeName')] = key;
+        log();
+    }
+
     run('timeout');
 
     env.global.log = log;
@@ -103,7 +111,7 @@ catch (e: any) {
         if ('name' in e) err += e.name + ": " + e.message;
         else err += 'Error: ' + e.message;
     }
-    else err += e;
+    else err += "[unknown]";
 
-    log(e);
-}
\ No newline at end of file
+    internals.log(err);
+}
diff --git a/lib/tsconfig.json b/lib/tsconfig.json
index f0ee4e3..326c2bd 100644
--- a/lib/tsconfig.json
+++ b/lib/tsconfig.json
@@ -2,7 +2,6 @@
     "files": [
         "lib.d.ts",
         "modules.ts",
-        "utils.ts",
         "regex.ts",
         "timeout.ts",
         "core.ts"
diff --git a/lib/utils.ts b/lib/utils.ts
deleted file mode 100644
index fe45aaf..0000000
--- a/lib/utils.ts
+++ /dev/null
@@ -1,27 +0,0 @@
-function setProps<
-    TargetT extends object,
-    DescT extends {
-        [x in Exclude<keyof TargetT, 'constructor'> ]?: TargetT[x] extends ((...args: infer ArgsT) => infer RetT) ?
-            ((this: TargetT, ...args: ArgsT) => RetT) :
-            TargetT[x]
-    }
->(target: TargetT, desc: DescT) {
-    var props = internals.keys(desc, false);
-    for (var i = 0; i in props; i++) {
-        var key = props[i];
-        internals.defineField(
-            target, key, (desc as any)[key],
-            true, // writable
-            false, // enumerable
-            true // configurable
-        );
-    }
-}
-function setConstr(target: object, constr: Function) {
-    internals.defineField(
-        target, 'constructor', constr,
-        true, // writable
-        false, // enumerable
-        true // configurable
-    );
-}
diff --git a/src/me/topchetoeu/jscript/engine/Environment.java b/src/me/topchetoeu/jscript/engine/Environment.java
index a146cba..e3e309b 100644
--- a/src/me/topchetoeu/jscript/engine/Environment.java
+++ b/src/me/topchetoeu/jscript/engine/Environment.java
@@ -22,7 +22,7 @@ public class Environment {
 
     @Native public FunctionValue compile;
     @Native public FunctionValue regexConstructor = new NativeFunction("RegExp", (ctx, thisArg, args) -> {
-        throw EngineException.ofError("Regular expressions not supported.");
+        throw EngineException.ofError("Regular expressions not supported.").setContext(ctx);
     });
     @Native public ObjectValue proto(String name) {
         return prototypes.get(name);
diff --git a/src/me/topchetoeu/jscript/engine/frame/CodeFrame.java b/src/me/topchetoeu/jscript/engine/frame/CodeFrame.java
index c503931..2ab02a3 100644
--- a/src/me/topchetoeu/jscript/engine/frame/CodeFrame.java
+++ b/src/me/topchetoeu/jscript/engine/frame/CodeFrame.java
@@ -24,7 +24,7 @@ public class CodeFrame {
         public final int tryStart, catchStart, finallyStart, end;
         public int state;
         public Object retVal;
-        public Object err;
+        public EngineException err;
         public int jumpPtr;
 
         public TryCtx(int tryStart, int tryN, int catchN, int finallyN) {
@@ -93,10 +93,11 @@ public class CodeFrame {
         stack[stackPtr++] = Values.normalize(ctx, val);
     }
 
-    private void setCause(Context ctx, Object err, Object cause) throws InterruptedException {
-        if (err instanceof ObjectValue) {
+    private void setCause(Context ctx, EngineException err, EngineException cause) throws InterruptedException {
+        if (err.value instanceof ObjectValue) {
             Values.setMember(ctx, err, ctx.env.symbol("Symbol.cause"), cause);
         }
+        err.cause = cause;
     }
     private Object nextNoTry(Context ctx) throws InterruptedException {
         if (Thread.currentThread().isInterrupted()) throw new InterruptedException();
@@ -116,12 +117,12 @@ public class CodeFrame {
         }
     }
 
-    public Object next(Context ctx, Object value, Object returnValue, Object error) throws InterruptedException {
+    public Object next(Context ctx, Object value, Object returnValue, EngineException error) throws InterruptedException {
         if (value != Runners.NO_RETURN) push(ctx, value);
 
-        if (returnValue == Runners.NO_RETURN && error == Runners.NO_RETURN) {
+        if (returnValue == Runners.NO_RETURN && error == null) {
             try { returnValue = nextNoTry(ctx); }
-            catch (EngineException e) { error = e.value; }
+            catch (EngineException e) { error = e; }
         }
 
         while (!tryStack.empty()) {
@@ -130,7 +131,7 @@ public class CodeFrame {
 
             switch (tryCtx.state) {
                 case TryCtx.STATE_TRY:
-                    if (error != Runners.NO_RETURN) {
+                    if (error != null) {
                         if (tryCtx.hasCatch) {
                             tryCtx.err = error;
                             newState = TryCtx.STATE_CATCH;
@@ -158,7 +159,7 @@ public class CodeFrame {
                     else codePtr = tryCtx.end;
                     break;
                 case TryCtx.STATE_CATCH:
-                    if (error != Runners.NO_RETURN) {
+                    if (error != null) {
                         if (tryCtx.hasFinally) {
                             tryCtx.err = error;
                             newState = TryCtx.STATE_FINALLY_THREW;
@@ -167,7 +168,7 @@ public class CodeFrame {
                     }
                     else if (returnValue != Runners.NO_RETURN) {
                         if (tryCtx.hasFinally) {
-                            tryCtx.retVal = error;
+                            tryCtx.retVal = returnValue;
                             newState = TryCtx.STATE_FINALLY_RETURNED;
                         }
                         break;
@@ -182,7 +183,7 @@ public class CodeFrame {
                     else codePtr = tryCtx.end;
                     break;
                 case TryCtx.STATE_FINALLY_THREW:
-                    if (error != Runners.NO_RETURN) setCause(ctx, error, tryCtx.err);
+                    if (error != null) setCause(ctx, error, tryCtx.err);
                     else if (codePtr < tryCtx.finallyStart || codePtr >= tryCtx.end) error = tryCtx.err;
                     else return Runners.NO_RETURN;
                     break;
@@ -211,7 +212,7 @@ public class CodeFrame {
             tryCtx.state = newState;
             switch (newState) {
                 case TryCtx.STATE_CATCH:
-                    scope.catchVars.add(new ValueVariable(false, tryCtx.err));
+                    scope.catchVars.add(new ValueVariable(false, tryCtx.err.value));
                     codePtr = tryCtx.catchStart;
                     break;
                 default:
@@ -221,7 +222,7 @@ public class CodeFrame {
             return Runners.NO_RETURN;
         }
     
-        if (error != Runners.NO_RETURN) throw new EngineException(error);
+        if (error != null) throw error.setContext(ctx);
         if (returnValue != Runners.NO_RETURN) return returnValue;
         return Runners.NO_RETURN;
     }
@@ -230,7 +231,7 @@ public class CodeFrame {
         try {
             ctx.message.pushFrame(ctx, this);
             while (true) {
-                var res = next(ctx, Runners.NO_RETURN, Runners.NO_RETURN, Runners.NO_RETURN);
+                var res = next(ctx, Runners.NO_RETURN, Runners.NO_RETURN, null);
                 if (res != Runners.NO_RETURN) return res;
             }
         }
diff --git a/src/me/topchetoeu/jscript/engine/values/Values.java b/src/me/topchetoeu/jscript/engine/values/Values.java
index d909ede..07a0036 100644
--- a/src/me/topchetoeu/jscript/engine/values/Values.java
+++ b/src/me/topchetoeu/jscript/engine/values/Values.java
@@ -685,7 +685,7 @@ public class Values {
         printValue(ctx, val, new HashSet<>(), 0);
     }
     public static void printError(RuntimeException err, String prefix) throws InterruptedException {
-        prefix = prefix == null ? "Uncauthg" : "Uncaught " + prefix;
+        prefix = prefix == null ? "Uncaught" : "Uncaught " + prefix;
         try {
             if (err instanceof EngineException) {
                 System.out.println(prefix + " " + ((EngineException)err).toString(((EngineException)err).ctx));
diff --git a/src/me/topchetoeu/jscript/parsing/Parsing.java b/src/me/topchetoeu/jscript/parsing/Parsing.java
index 54725b9..16d2f8c 100644
--- a/src/me/topchetoeu/jscript/parsing/Parsing.java
+++ b/src/me/topchetoeu/jscript/parsing/Parsing.java
@@ -685,7 +685,7 @@ public class Parsing {
         }
 
     }
-    public static ParseRes<NewStatement> parseRegex(String filename, List<Token> tokens, int i) {
+    public static ParseRes<RegexStatement> parseRegex(String filename, List<Token> tokens, int i) {
         var loc = getLoc(filename, tokens, i);
         try {
             if (tokens.get(i).isRegex()) {
@@ -693,11 +693,7 @@ public class Parsing {
                 var index = val.lastIndexOf('/');
                 var first = val.substring(1, index);
                 var second = val.substring(index + 1);
-                return ParseRes.res(new NewStatement(loc,
-                    new VariableStatement(null, "RegExp"),
-                    new ConstantStatement(loc, first),
-                    new ConstantStatement(loc, second)
-                ), 1);
+                return ParseRes.res(new RegexStatement(loc, first, second), 1);
             }
             else return ParseRes.failed();
         }
diff --git a/src/me/topchetoeu/jscript/polyfills/ArrayPolyfill.java b/src/me/topchetoeu/jscript/polyfills/ArrayPolyfill.java
index 499c620..a2901a7 100644
--- a/src/me/topchetoeu/jscript/polyfills/ArrayPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/ArrayPolyfill.java
@@ -14,7 +14,6 @@ import me.topchetoeu.jscript.interop.NativeGetter;
 import me.topchetoeu.jscript.interop.NativeSetter;
 
 public class ArrayPolyfill {
-    @Native("@@Symbol.typeName") public final String name = "AsyncFunction";
     @NativeGetter(thisArg = true) public static int length(Context ctx, ArrayValue thisArg) throws InterruptedException {
         return thisArg.size();
     }
diff --git a/src/me/topchetoeu/jscript/polyfills/AsyncFunctionPolyfill.java b/src/me/topchetoeu/jscript/polyfills/AsyncFunctionPolyfill.java
index 3aad543..951c6c5 100644
--- a/src/me/topchetoeu/jscript/polyfills/AsyncFunctionPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/AsyncFunctionPolyfill.java
@@ -26,7 +26,7 @@ public class AsyncFunctionPolyfill extends FunctionValue {
             awaiting = false;
             while (!awaiting) {
                 try {
-                    res = frame.next(ctx, inducedValue, Runners.NO_RETURN, inducedError);
+                    res = frame.next(ctx, inducedValue, Runners.NO_RETURN, inducedError == Runners.NO_RETURN ? null : new EngineException(inducedError));
                     inducedValue = inducedError = Runners.NO_RETURN;
                     if (res != Runners.NO_RETURN) {
                         promise.fulfill(ctx, res);
diff --git a/src/me/topchetoeu/jscript/polyfills/AsyncGeneratorPolyfill.java b/src/me/topchetoeu/jscript/polyfills/AsyncGeneratorPolyfill.java
index 801cc8b..18950e3 100644
--- a/src/me/topchetoeu/jscript/polyfills/AsyncGeneratorPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/AsyncGeneratorPolyfill.java
@@ -39,7 +39,7 @@ public class AsyncGeneratorPolyfill extends FunctionValue {
 
             while (state == 0) {
                 try {
-                    res = frame.next(ctx, inducedValue, inducedReturn, inducedError);
+                    res = frame.next(ctx, inducedValue, inducedReturn, inducedError == Runners.NO_RETURN ? null : new EngineException(inducedError));
                     inducedValue = inducedReturn = inducedError = Runners.NO_RETURN;
                     if (res != Runners.NO_RETURN) {
                         var obj = new ObjectValue();
diff --git a/src/me/topchetoeu/jscript/polyfills/BooleanPolyfill.java b/src/me/topchetoeu/jscript/polyfills/BooleanPolyfill.java
index df824b0..843e78b 100644
--- a/src/me/topchetoeu/jscript/polyfills/BooleanPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/BooleanPolyfill.java
@@ -7,8 +7,6 @@ import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
 
 public class BooleanPolyfill {
-    @Native("@@Symbol.typeName") public final String name = "Boolean";
-
     public static final BooleanPolyfill TRUE = new BooleanPolyfill(true);
     public static final BooleanPolyfill FALSE = new BooleanPolyfill(false);
 
diff --git a/src/me/topchetoeu/jscript/polyfills/ErrorPolyfill.java b/src/me/topchetoeu/jscript/polyfills/ErrorPolyfill.java
index 540cd55..2e694a8 100644
--- a/src/me/topchetoeu/jscript/polyfills/ErrorPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/ErrorPolyfill.java
@@ -30,7 +30,7 @@ public class ErrorPolyfill {
         }
     }
 
-    private static String toString(Context ctx, Object name, Object message, ArrayValue stack) throws InterruptedException {
+    private static String toString(Context ctx, Object cause, Object name, Object message, ArrayValue stack) throws InterruptedException {
         if (name == null) name = "";
         else name = Values.toString(ctx, name).trim();
         if (message == null) message = "";
@@ -39,7 +39,7 @@ public class ErrorPolyfill {
 
         if (!name.equals("")) res.append(name);
         if (!message.equals("") && !name.equals("")) res.append(": ");
-        if (!name.equals("")) res.append(message);
+        if (!message.equals("")) res.append(message);
 
         if (stack != null) {
             for (var el : stack) {
@@ -48,6 +48,8 @@ public class ErrorPolyfill {
             }
         }
 
+        if (cause instanceof ObjectValue) res.append(toString(ctx, cause));
+
         return res.toString();
     }
 
@@ -56,6 +58,7 @@ public class ErrorPolyfill {
             var stack = Values.getMember(ctx, thisArg, "stack");
             if (!(stack instanceof ArrayValue)) stack = null;
             return toString(ctx,
+                Values.getMember(ctx, thisArg, "cause"),
                 Values.getMember(ctx, thisArg, "name"),
                 Values.getMember(ctx, thisArg, "message"),
                 (ArrayValue)stack
diff --git a/src/me/topchetoeu/jscript/polyfills/FunctionPolyfill.java b/src/me/topchetoeu/jscript/polyfills/FunctionPolyfill.java
index 7fbdbc7..e46e674 100644
--- a/src/me/topchetoeu/jscript/polyfills/FunctionPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/FunctionPolyfill.java
@@ -8,9 +8,7 @@ import me.topchetoeu.jscript.exceptions.EngineException;
 import me.topchetoeu.jscript.interop.Native;
 
 public class FunctionPolyfill {
-        @Native("@@Symbol.typeName") public final String name = "Function";
-
-        @Native(thisArg = true) public static Object apply(Context ctx, FunctionValue func, Object thisArg, ArrayValue args) throws InterruptedException {
+    @Native(thisArg = true) public static Object apply(Context ctx, FunctionValue func, Object thisArg, ArrayValue args) throws InterruptedException {
         return func.call(ctx, thisArg, args.toArray());
     }
     @Native(thisArg = true) public static Object call(Context ctx, FunctionValue func, Object thisArg, Object... args) throws InterruptedException {
diff --git a/src/me/topchetoeu/jscript/polyfills/GeneratorPolyfill.java b/src/me/topchetoeu/jscript/polyfills/GeneratorPolyfill.java
index 6da8d8f..db176ed 100644
--- a/src/me/topchetoeu/jscript/polyfills/GeneratorPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/GeneratorPolyfill.java
@@ -35,7 +35,7 @@ public class GeneratorPolyfill extends FunctionValue {
 
             while (!yielding) {
                 try {
-                    res = frame.next(ctx, inducedValue, inducedReturn, inducedError);
+                    res = frame.next(ctx, inducedValue, inducedReturn, inducedError == Runners.NO_RETURN ? null : new EngineException(inducedError));
                     inducedReturn = inducedError = Runners.NO_RETURN;
                     if (res != Runners.NO_RETURN) {
                         done = true;
diff --git a/src/me/topchetoeu/jscript/polyfills/Internals.java b/src/me/topchetoeu/jscript/polyfills/Internals.java
index e53d6f5..643ab8f 100644
--- a/src/me/topchetoeu/jscript/polyfills/Internals.java
+++ b/src/me/topchetoeu/jscript/polyfills/Internals.java
@@ -20,7 +20,7 @@ public class Internals {
     @Native public final FunctionValue
         object, function, array,
         bool, number, string, symbol,
-        promise, map, set,
+        promise, map, set, regexp,
         error, syntax, type, range;
 
     @Native public void markSpecial(FunctionValue ...funcs) {
@@ -174,5 +174,6 @@ public class Internals {
         this.syntax = targetEnv.wrappersProvider.getConstr(SyntaxErrorPolyfill.class);
         this.type = targetEnv.wrappersProvider.getConstr(TypeErrorPolyfill.class);
         this.range = targetEnv.wrappersProvider.getConstr(RangeErrorPolyfill.class);
+        this.regexp = targetEnv.wrappersProvider.getConstr(RegExpPolyfill.class);
     }
 }
diff --git a/src/me/topchetoeu/jscript/polyfills/JSON.java b/src/me/topchetoeu/jscript/polyfills/JSONPolyfill.java
similarity index 95%
rename from src/me/topchetoeu/jscript/polyfills/JSON.java
rename to src/me/topchetoeu/jscript/polyfills/JSONPolyfill.java
index 53873a5..9d70719 100644
--- a/src/me/topchetoeu/jscript/polyfills/JSON.java
+++ b/src/me/topchetoeu/jscript/polyfills/JSONPolyfill.java
@@ -1,85 +1,85 @@
-package me.topchetoeu.jscript.polyfills;
-
-import java.util.HashSet;
-import java.util.stream.Collectors;
-
-import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.values.ArrayValue;
-import me.topchetoeu.jscript.engine.values.ObjectValue;
-import me.topchetoeu.jscript.engine.values.Values;
-import me.topchetoeu.jscript.exceptions.EngineException;
-import me.topchetoeu.jscript.exceptions.SyntaxException;
-import me.topchetoeu.jscript.interop.Native;
-import me.topchetoeu.jscript.json.JSONElement;
-import me.topchetoeu.jscript.json.JSONList;
-import me.topchetoeu.jscript.json.JSONMap;
-
-public class JSON {
-    private static Object toJS(JSONElement val) {
-        if (val.isBoolean()) return val.bool();
-        if (val.isString()) return val.string();
-        if (val.isNumber()) return val.number();
-        if (val.isList()) return ArrayValue.of(null, val.list().stream().map(JSON::toJS).collect(Collectors.toList()));
-        if (val.isMap()) {
-            var res = new ObjectValue();
-            for (var el : val.map().entrySet()) {
-                res.defineProperty(null, el.getKey(), toJS(el.getValue()));
-            }
-            return res;
-        }
-        if (val.isNull()) return Values.NULL;
-        return null;
-    }
-    private static JSONElement toJSON(Context ctx, Object val, HashSet<Object> prev) throws InterruptedException {
-        if (val instanceof Boolean) return JSONElement.bool((boolean)val);
-        if (val instanceof Number) return JSONElement.number(((Number)val).doubleValue());
-        if (val instanceof String) return JSONElement.string((String)val);
-        if (val == Values.NULL) return JSONElement.NULL;
-        if (val instanceof ObjectValue) {
-            if (prev.contains(val)) throw new EngineException("Circular dependency in JSON.");
-            prev.add(val);
-
-            var res = new JSONMap();
-
-            for (var el : ((ObjectValue)val).keys(false)) {
-                var jsonEl = toJSON(ctx, ((ObjectValue)val).getMember(ctx, el), prev);
-                if (jsonEl == null) continue;
-                if (el instanceof String || el instanceof Number) res.put(el.toString(), jsonEl);
-            }
-
-            prev.remove(val);
-            return JSONElement.of(res);
-        }
-        if (val instanceof ArrayValue) {
-            if (prev.contains(val)) throw new EngineException("Circular dependency in JSON.");
-            prev.add(val);
-
-            var res = new JSONList();
-
-            for (var el : ((ArrayValue)val).toArray()) {
-                var jsonEl = toJSON(ctx, el, prev);
-                if (jsonEl == null) jsonEl = JSONElement.NULL;
-                res.add(jsonEl);
-            }
-
-            prev.remove(val);
-            return JSONElement.of(res);
-        }
-        if (val == null) return null;
-        return null;
-    }
-
-    @Native
-    public static Object parse(Context ctx, String val) throws InterruptedException {
-        try {
-            return toJS(me.topchetoeu.jscript.json.JSON.parse("<value>", val));
-        }
-        catch (SyntaxException e) {
-            throw EngineException.ofSyntax(e.msg);
-        }
-    }
-    @Native
-    public static String stringify(Context ctx, Object val) throws InterruptedException {
-        return me.topchetoeu.jscript.json.JSON.stringify(toJSON(ctx, val, new HashSet<>()));
-    }
-}
+package me.topchetoeu.jscript.polyfills;
+
+import java.util.HashSet;
+import java.util.stream.Collectors;
+
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.values.ArrayValue;
+import me.topchetoeu.jscript.engine.values.ObjectValue;
+import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.exceptions.EngineException;
+import me.topchetoeu.jscript.exceptions.SyntaxException;
+import me.topchetoeu.jscript.interop.Native;
+import me.topchetoeu.jscript.json.JSONElement;
+import me.topchetoeu.jscript.json.JSONList;
+import me.topchetoeu.jscript.json.JSONMap;
+
+public class JSONPolyfill {
+    private static Object toJS(JSONElement val) {
+        if (val.isBoolean()) return val.bool();
+        if (val.isString()) return val.string();
+        if (val.isNumber()) return val.number();
+        if (val.isList()) return ArrayValue.of(null, val.list().stream().map(JSONPolyfill::toJS).collect(Collectors.toList()));
+        if (val.isMap()) {
+            var res = new ObjectValue();
+            for (var el : val.map().entrySet()) {
+                res.defineProperty(null, el.getKey(), toJS(el.getValue()));
+            }
+            return res;
+        }
+        if (val.isNull()) return Values.NULL;
+        return null;
+    }
+    private static JSONElement toJSON(Context ctx, Object val, HashSet<Object> prev) throws InterruptedException {
+        if (val instanceof Boolean) return JSONElement.bool((boolean)val);
+        if (val instanceof Number) return JSONElement.number(((Number)val).doubleValue());
+        if (val instanceof String) return JSONElement.string((String)val);
+        if (val == Values.NULL) return JSONElement.NULL;
+        if (val instanceof ObjectValue) {
+            if (prev.contains(val)) throw new EngineException("Circular dependency in JSON.");
+            prev.add(val);
+
+            var res = new JSONMap();
+
+            for (var el : ((ObjectValue)val).keys(false)) {
+                var jsonEl = toJSON(ctx, ((ObjectValue)val).getMember(ctx, el), prev);
+                if (jsonEl == null) continue;
+                if (el instanceof String || el instanceof Number) res.put(el.toString(), jsonEl);
+            }
+
+            prev.remove(val);
+            return JSONElement.of(res);
+        }
+        if (val instanceof ArrayValue) {
+            if (prev.contains(val)) throw new EngineException("Circular dependency in JSON.");
+            prev.add(val);
+
+            var res = new JSONList();
+
+            for (var el : ((ArrayValue)val).toArray()) {
+                var jsonEl = toJSON(ctx, el, prev);
+                if (jsonEl == null) jsonEl = JSONElement.NULL;
+                res.add(jsonEl);
+            }
+
+            prev.remove(val);
+            return JSONElement.of(res);
+        }
+        if (val == null) return null;
+        return null;
+    }
+
+    @Native
+    public static Object parse(Context ctx, String val) throws InterruptedException {
+        try {
+            return toJS(me.topchetoeu.jscript.json.JSON.parse("<value>", val));
+        }
+        catch (SyntaxException e) {
+            throw EngineException.ofSyntax(e.msg);
+        }
+    }
+    @Native
+    public static String stringify(Context ctx, Object val) throws InterruptedException {
+        return me.topchetoeu.jscript.json.JSON.stringify(toJSON(ctx, val, new HashSet<>()));
+    }
+}
diff --git a/src/me/topchetoeu/jscript/polyfills/MapPolyfill.java b/src/me/topchetoeu/jscript/polyfills/MapPolyfill.java
index ce4277e..f747164 100644
--- a/src/me/topchetoeu/jscript/polyfills/MapPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/MapPolyfill.java
@@ -13,7 +13,6 @@ import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeGetter;
 
 public class MapPolyfill {
-    @Native("@@Symbol.typeName") public final String name = "Map";
     private LinkedHashMap<Object, Object> map = new LinkedHashMap<>();
 
     @Native("@@Symbol.iterator") public ObjectValue iterator(Context ctx) throws InterruptedException {
diff --git a/src/me/topchetoeu/jscript/polyfills/NumberPolyfill.java b/src/me/topchetoeu/jscript/polyfills/NumberPolyfill.java
index ddc89a1..a3859eb 100644
--- a/src/me/topchetoeu/jscript/polyfills/NumberPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/NumberPolyfill.java
@@ -7,8 +7,6 @@ import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
 
 public class NumberPolyfill {
-    @Native("@@Symbol.typeName") public final String name = "Number";
-
     @Native public static final double EPSILON = java.lang.Math.ulp(1.0);
     @Native public static final double MAX_SAFE_INTEGER = 9007199254740991.;
     @Native public static final double MIN_SAFE_INTEGER = -MAX_SAFE_INTEGER;
diff --git a/src/me/topchetoeu/jscript/polyfills/ObjectPolyfill.java b/src/me/topchetoeu/jscript/polyfills/ObjectPolyfill.java
index 9875a74..51c12e9 100644
--- a/src/me/topchetoeu/jscript/polyfills/ObjectPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/ObjectPolyfill.java
@@ -11,8 +11,6 @@ import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeConstructor;
 
 public class ObjectPolyfill {
-    @Native("@@Symbol.typeName") public final String name = "Object";
-
     @Native public static ObjectValue assign(Context ctx, ObjectValue dst, Object... src) throws InterruptedException {
         for (var obj : src) {
             for (var key : Values.getMembers(ctx, obj, true, true)) {
diff --git a/src/me/topchetoeu/jscript/polyfills/PromisePolyfill.java b/src/me/topchetoeu/jscript/polyfills/PromisePolyfill.java
index 41e977d..741f052 100644
--- a/src/me/topchetoeu/jscript/polyfills/PromisePolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/PromisePolyfill.java
@@ -28,8 +28,6 @@ public class PromisePolyfill {
         }
     }
 
-    @Native("@@Symbol.typeName") public final String name = "Promise";
-
     @Native("resolve")
     public static PromisePolyfill ofResolved(Context ctx, Object val) throws InterruptedException {
         var res = new PromisePolyfill();
diff --git a/src/me/topchetoeu/jscript/polyfills/RegExp.java b/src/me/topchetoeu/jscript/polyfills/RegExp.java
deleted file mode 100644
index 804d0e7..0000000
--- a/src/me/topchetoeu/jscript/polyfills/RegExp.java
+++ /dev/null
@@ -1,187 +0,0 @@
-package me.topchetoeu.jscript.polyfills;
-
-import java.util.ArrayList;
-import java.util.regex.Pattern;
-
-import me.topchetoeu.jscript.engine.Context;
-import me.topchetoeu.jscript.engine.values.ArrayValue;
-import me.topchetoeu.jscript.engine.values.NativeWrapper;
-import me.topchetoeu.jscript.engine.values.ObjectValue;
-import me.topchetoeu.jscript.engine.values.Values;
-import me.topchetoeu.jscript.interop.Native;
-import me.topchetoeu.jscript.interop.NativeGetter;
-import me.topchetoeu.jscript.interop.NativeSetter;
-
-public class RegExp {
-    // I used Regex to analyze Regex
-    private static final Pattern NAMED_PATTERN = Pattern.compile("\\(\\?<([^=!].*?)>", Pattern.DOTALL);
-    private static final Pattern ESCAPE_PATTERN = Pattern.compile("[/\\-\\\\^$*+?.()|\\[\\]{}]");
-
-    private static String cleanupPattern(Context ctx, Object val) throws InterruptedException {
-        if (val == null) return "(?:)";
-        if (val instanceof RegExp) return ((RegExp)val).source;
-        if (val instanceof NativeWrapper && ((NativeWrapper)val).wrapped instanceof RegExp) {
-            return ((RegExp)((NativeWrapper)val).wrapped).source;
-        }
-        var res = Values.toString(ctx, val);
-        if (res.equals("")) return "(?:)";
-        return res;
-    }
-    private static String cleanupFlags(Context ctx, Object val) throws InterruptedException {
-        if (val == null) return "";
-        return Values.toString(ctx, val);
-    }
-
-    private static boolean checkEscaped(String s, int pos) {
-        int n = 0;
-
-        while (true) {
-            if (pos <= 0) break;
-            if (s.charAt(pos) != '\\') break;
-            n++;
-            pos--;
-        }
-
-        return (n % 2) != 0;
-    }
-
-    @Native
-    public static RegExp escape(Context ctx, Object raw, Object flags) throws InterruptedException {
-        return escape(Values.toString(ctx, raw), cleanupFlags(ctx, flags));
-    }
-    public static RegExp escape(String raw, String flags) {
-        return new RegExp(ESCAPE_PATTERN.matcher(raw).replaceAll("\\\\$0"), flags);
-    }
-
-    private Pattern pattern;
-    private String[] namedGroups;
-    private int flags;
-    private int lastI = 0;
-
-    @Native
-    public final String source;
-    @Native
-    public final boolean hasIndices;
-    @Native
-    public final boolean global;
-    @Native
-    public final boolean sticky;
-
-    @NativeGetter("ignoreCase")
-    public boolean ignoreCase() { return (flags & Pattern.CASE_INSENSITIVE) != 0; }
-    @NativeGetter("multiline")
-    public boolean multiline() { return (flags & Pattern.MULTILINE) != 0; }
-    @NativeGetter("unicode")
-    public boolean unicode() { return (flags & Pattern.UNICODE_CHARACTER_CLASS) != 0; }
-    @NativeGetter("unicode")
-    public boolean dotAll() { return (flags & Pattern.DOTALL) != 0; }
-
-    @NativeGetter("lastIndex")
-    public int lastIndex() { return lastI; }
-    @NativeSetter("lastIndex")
-    public void setLastIndex(Context ctx, Object i) throws InterruptedException {
-        lastI = (int)Values.toNumber(ctx, i);
-    }
-    public void setLastIndex(int i) {
-        lastI = i;
-    }
-
-    @NativeGetter("flags")
-    public final String flags() {
-        String res = "";
-        if (hasIndices) res += 'd';
-        if (global) res += 'g';
-        if (ignoreCase()) res += 'i';
-        if (multiline()) res += 'm';
-        if (dotAll()) res += 's';
-        if (unicode()) res += 'u';
-        if (sticky) res += 'y';
-        return res;
-    }
-
-    @Native
-    public Object exec(Context ctx, Object str) throws InterruptedException {
-        return exec(Values.toString(ctx, str));
-    }
-    public Object exec(String str) {
-        var matcher = pattern.matcher(str);
-        if (lastI > str.length() || !matcher.find(lastI) || sticky && matcher.start() != lastI) {
-            lastI = 0;
-            return Values.NULL;
-        }
-        if (sticky || global) {
-            lastI = matcher.end();
-            if (matcher.end() == matcher.start()) lastI++;
-        }
-
-        var obj = new ArrayValue();
-        var groups = new ObjectValue();
-
-        for (var el : namedGroups) {
-            try {
-                groups.defineProperty(null, el, matcher.group(el));
-            }
-            catch (IllegalArgumentException e) { }
-        }
-        if (groups.values.size() == 0) groups = null;
-
-
-        for (int i = 0; i < matcher.groupCount() + 1; i++) {
-            obj.set(null, i, matcher.group(i));
-        }
-        obj.defineProperty(null, "groups", groups);
-        obj.defineProperty(null, "index", matcher.start());
-        obj.defineProperty(null, "input", str);
-
-        if (hasIndices) {
-            var indices = new ArrayValue();
-            for (int i = 0; i < matcher.groupCount() + 1; i++) {
-                indices.set(null, i, new ArrayValue(null, matcher.start(i), matcher.end(i)));
-            }
-            var groupIndices = new ObjectValue();
-            for (var el : namedGroups) {
-                groupIndices.defineProperty(null, el, new ArrayValue(null, matcher.start(el), matcher.end(el)));
-            }
-            indices.defineProperty(null, "groups", groupIndices);
-            obj.defineProperty(null, "indices", indices);
-        }
-
-        return obj;
-    }
-
-    @Native
-    public RegExp(Context ctx, Object pattern, Object flags) throws InterruptedException {
-        this(cleanupPattern(ctx, pattern), cleanupFlags(ctx, flags));
-    }
-    public RegExp(String pattern, String flags) {
-        if (pattern == null || pattern.equals("")) pattern = "(?:)";
-        if (flags == null || flags.equals("")) flags = "";
-
-        this.flags = 0;
-        this.hasIndices = flags.contains("d");
-        this.global = flags.contains("g");
-        this.sticky = flags.contains("y");
-        this.source = pattern;
-
-        if (flags.contains("i")) this.flags |= Pattern.CASE_INSENSITIVE;
-        if (flags.contains("m")) this.flags |= Pattern.MULTILINE;
-        if (flags.contains("s")) this.flags |= Pattern.DOTALL;
-        if (flags.contains("u")) this.flags |= Pattern.UNICODE_CHARACTER_CLASS;
-
-        this.pattern = Pattern.compile(pattern.replace("\\d", "[0-9]"), this.flags);
-
-        var matcher = NAMED_PATTERN.matcher(source);
-        var groups = new ArrayList<String>();
-
-        while (matcher.find()) {
-            if (!checkEscaped(source, matcher.start() - 1)) {
-                groups.add(matcher.group(1));
-            }
-        }
-
-        namedGroups = groups.toArray(String[]::new);
-    }
-
-    public RegExp(String pattern) { this(pattern, null); }
-    public RegExp() { this(null, null); }
-}
diff --git a/src/me/topchetoeu/jscript/polyfills/RegExpPolyfill.java b/src/me/topchetoeu/jscript/polyfills/RegExpPolyfill.java
new file mode 100644
index 0000000..373bff1
--- /dev/null
+++ b/src/me/topchetoeu/jscript/polyfills/RegExpPolyfill.java
@@ -0,0 +1,296 @@
+package me.topchetoeu.jscript.polyfills;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.regex.Pattern;
+
+import me.topchetoeu.jscript.engine.Context;
+import me.topchetoeu.jscript.engine.values.ArrayValue;
+import me.topchetoeu.jscript.engine.values.NativeWrapper;
+import me.topchetoeu.jscript.engine.values.ObjectValue;
+import me.topchetoeu.jscript.engine.values.Values;
+import me.topchetoeu.jscript.interop.Native;
+import me.topchetoeu.jscript.interop.NativeGetter;
+
+public class RegExpPolyfill {
+    // I used Regex to analyze Regex
+    private static final Pattern NAMED_PATTERN = Pattern.compile("\\(\\?<([^=!].*?)>", Pattern.DOTALL);
+    private static final Pattern ESCAPE_PATTERN = Pattern.compile("[/\\-\\\\^$*+?.()|\\[\\]{}]");
+
+    private static String cleanupPattern(Context ctx, Object val) throws InterruptedException {
+        if (val == null) return "(?:)";
+        if (val instanceof RegExpPolyfill) return ((RegExpPolyfill)val).source;
+        if (val instanceof NativeWrapper && ((NativeWrapper)val).wrapped instanceof RegExpPolyfill) {
+            return ((RegExpPolyfill)((NativeWrapper)val).wrapped).source;
+        }
+        var res = Values.toString(ctx, val);
+        if (res.equals("")) return "(?:)";
+        return res;
+    }
+    private static String cleanupFlags(Context ctx, Object val) throws InterruptedException {
+        if (val == null) return "";
+        return Values.toString(ctx, val);
+    }
+
+    private static boolean checkEscaped(String s, int pos) {
+        int n = 0;
+
+        while (true) {
+            if (pos <= 0) break;
+            if (s.charAt(pos) != '\\') break;
+            n++;
+            pos--;
+        }
+
+        return (n % 2) != 0;
+    }
+
+    @Native
+    public static RegExpPolyfill escape(Context ctx, Object raw, Object flags) throws InterruptedException {
+        return escape(Values.toString(ctx, raw), cleanupFlags(ctx, flags));
+    }
+    public static RegExpPolyfill escape(String raw, String flags) {
+        return new RegExpPolyfill(ESCAPE_PATTERN.matcher(raw).replaceAll("\\\\$0"), flags);
+    }
+
+    private Pattern pattern;
+    private String[] namedGroups;
+    private int flags;
+    
+    @Native public int lastI = 0;
+    @Native public final String source;
+    @Native public final boolean hasIndices;
+    @Native public final boolean global;
+    @Native public final boolean sticky;
+
+    @NativeGetter public boolean ignoreCase() { return (flags & Pattern.CASE_INSENSITIVE) != 0; }
+    @NativeGetter public boolean multiline() { return (flags & Pattern.MULTILINE) != 0; }
+    @NativeGetter public boolean unicode() { return (flags & Pattern.UNICODE_CHARACTER_CLASS) != 0; }
+    @NativeGetter public boolean dotAll() { return (flags & Pattern.DOTALL) != 0; }
+
+    @NativeGetter("flags") public final String flags() {
+        String res = "";
+        if (hasIndices) res += 'd';
+        if (global) res += 'g';
+        if (ignoreCase()) res += 'i';
+        if (multiline()) res += 'm';
+        if (dotAll()) res += 's';
+        if (unicode()) res += 'u';
+        if (sticky) res += 'y';
+        return res;
+    }
+
+    
+    @Native public Object exec(String str) {
+        var matcher = pattern.matcher(str);
+        if (lastI > str.length() || !matcher.find(lastI) || sticky && matcher.start() != lastI) {
+            lastI = 0;
+            return Values.NULL;
+        }
+        if (sticky || global) {
+            lastI = matcher.end();
+            if (matcher.end() == matcher.start()) lastI++;
+        }
+
+        var obj = new ArrayValue();
+        var groups = new ObjectValue();
+
+        for (var el : namedGroups) {
+            try {
+                groups.defineProperty(null, el, matcher.group(el));
+            }
+            catch (IllegalArgumentException e) { }
+        }
+        if (groups.values.size() == 0) groups = null;
+
+
+        for (int i = 0; i < matcher.groupCount() + 1; i++) {
+            obj.set(null, i, matcher.group(i));
+        }
+        obj.defineProperty(null, "groups", groups);
+        obj.defineProperty(null, "index", matcher.start());
+        obj.defineProperty(null, "input", str);
+
+        if (hasIndices) {
+            var indices = new ArrayValue();
+            for (int i = 0; i < matcher.groupCount() + 1; i++) {
+                indices.set(null, i, new ArrayValue(null, matcher.start(i), matcher.end(i)));
+            }
+            var groupIndices = new ObjectValue();
+            for (var el : namedGroups) {
+                groupIndices.defineProperty(null, el, new ArrayValue(null, matcher.start(el), matcher.end(el)));
+            }
+            indices.defineProperty(null, "groups", groupIndices);
+            obj.defineProperty(null, "indices", indices);
+        }
+
+        return obj;
+    }
+
+    @Native public boolean test(String str) {
+        return this.exec(str) != Values.NULL;
+    }
+    @Native public String toString() {
+        return "/" + source + "/" + flags();
+    }
+
+    @Native("@@Symvol.match") public Object match(Context ctx, String target) throws InterruptedException {
+        if (this.global) {
+            var res = new ArrayValue();
+            Object val;
+            while ((val = this.exec(target)) != Values.NULL) {
+                res.set(ctx, res.size(), Values.getMember(ctx, val, 0));
+            }
+            lastI = 0;
+            return res;
+        }
+        else {
+            var res = this.exec(target);
+            if (!this.sticky) this.lastI = 0;
+            return res;
+        }
+    }
+
+    @Native("@@Symvol.matchAll") public Object matchAll(Context ctx, String target) throws InterruptedException {
+        var pattern = new RegExpPolyfill(this.source, this.flags() + "g");
+
+        return Values.fromJavaIterator(ctx, new Iterator<Object>() {
+            private Object val = null;
+            private boolean updated = false;
+
+            private void update() {
+                if (!updated) val = pattern.exec(target);
+            }
+            @Override public boolean hasNext() {
+                update();
+                return val != Values.NULL;
+            }
+            @Override public Object next() {
+                update();
+                updated = false;
+                return val;
+            }
+        });
+    }
+    
+    @Native("@@Symvol.split") public ArrayValue split(Context ctx, String target, Object limit, boolean sensible) throws InterruptedException {
+        var pattern = new RegExpPolyfill(this.source, this.flags() + "g");
+        Object match;
+        int lastEnd = 0;
+        var res = new ArrayValue();
+        var lim = limit == null ? 0 : Values.toNumber(ctx, limit);
+
+        while ((match = pattern.exec(target)) != Values.NULL) {
+            var added = new ArrayList<String>();
+            var arrMatch = (ArrayValue)match;
+            int index = (int)Values.toNumber(ctx, Values.getMember(ctx, match, "index"));
+            var matchVal = (String)arrMatch.get(0);
+
+            if (index >= target.length()) break;
+
+            if (matchVal.length() == 0 || index - lastEnd > 0) {
+                added.add(target.substring(lastEnd, pattern.lastI));
+                if (pattern.lastI < target.length()) {
+                    for (var i = 1; i < arrMatch.size(); i++) added.add((String)arrMatch.get(i));
+                }
+            }
+            else {
+                for (var i = 1; i < arrMatch.size(); i++) added.add((String)arrMatch.get(i));
+            }
+
+            if (sensible) {
+                if (limit != null && res.size() + added.size() >= lim) break;
+                else for (var i = 0; i < added.size(); i++) res.set(ctx, res.size(), added.get(i));
+            }
+            else {
+                for (var i = 0; i < added.size(); i++) {
+                    if (limit != null && res.size() >= lim) return res;
+                    else res.set(ctx, res.size(), added.get(i));
+                }
+            }
+            lastEnd = pattern.lastI;
+        }
+        if (lastEnd < target.length()) {
+            res.set(ctx, res.size(), target.substring(lastEnd));
+        }
+        return res;
+    }
+    // [Symbol.replace](target, replacement) {
+    //     const pattern = new this.constructor(this, this.flags + "d") as RegExp;
+    //     let match: RegExpResult | null;
+    //     let lastEnd = 0;
+    //     const res: string[] = [];
+    //     // log(pattern.toString());
+    //     while ((match = pattern.exec(target)) !== null) {
+    //         const indices = match.indices![0];
+    //         res.push(target.substring(lastEnd, indices[0]));
+    //         if (replacement instanceof Function) {
+    //             res.push(replacement(target.substring(indices[0], indices[1]), ...match.slice(1), indices[0], target));
+    //         }
+    //         else {
+    //             res.push(replacement);
+    //         }
+    //         lastEnd = indices[1];
+    //         if (!pattern.global) break;
+    //     }
+    //     if (lastEnd < target.length) {
+    //         res.push(target.substring(lastEnd));
+    //     }
+    //     return res.join('');
+    // },
+    // [Symbol.search](target, reverse, start) {
+    //     const pattern: RegExp | undefined = new this.constructor(this, this.flags + "g") as RegExp;
+    //     if (!reverse) {
+    //         pattern.lastIndex = (start as any) | 0;
+    //         const res = pattern.exec(target);
+    //         if (res) return res.index;
+    //         else return -1;
+    //     }
+    //     else {
+    //         start ??= target.length;
+    //         start |= 0;
+    //         let res: RegExpResult | null = null;
+    //         while (true) {
+    //             const tmp = pattern.exec(target);
+    //             if (tmp === null || tmp.index > start) break;
+    //             res = tmp;
+    //         }
+    //         if (res && res.index <= start) return res.index;
+    //         else return -1;
+    //     }
+    // },
+    @Native public RegExpPolyfill(Context ctx, Object pattern, Object flags) throws InterruptedException {
+        this(cleanupPattern(ctx, pattern), cleanupFlags(ctx, flags));
+    }
+    public RegExpPolyfill(String pattern, String flags) {
+        if (pattern == null || pattern.equals("")) pattern = "(?:)";
+        if (flags == null || flags.equals("")) flags = "";
+
+        this.flags = 0;
+        this.hasIndices = flags.contains("d");
+        this.global = flags.contains("g");
+        this.sticky = flags.contains("y");
+        this.source = pattern;
+
+        if (flags.contains("i")) this.flags |= Pattern.CASE_INSENSITIVE;
+        if (flags.contains("m")) this.flags |= Pattern.MULTILINE;
+        if (flags.contains("s")) this.flags |= Pattern.DOTALL;
+        if (flags.contains("u")) this.flags |= Pattern.UNICODE_CHARACTER_CLASS;
+
+        this.pattern = Pattern.compile(pattern.replace("\\d", "[0-9]"), this.flags);
+
+        var matcher = NAMED_PATTERN.matcher(source);
+        var groups = new ArrayList<String>();
+
+        while (matcher.find()) {
+            if (!checkEscaped(source, matcher.start() - 1)) {
+                groups.add(matcher.group(1));
+            }
+        }
+
+        namedGroups = groups.toArray(String[]::new);
+    }
+
+    public RegExpPolyfill(String pattern) { this(pattern, null); }
+    public RegExpPolyfill() { this(null, null); }
+}
diff --git a/src/me/topchetoeu/jscript/polyfills/SetPolyfill.java b/src/me/topchetoeu/jscript/polyfills/SetPolyfill.java
index 7822f2a..9fd9bbd 100644
--- a/src/me/topchetoeu/jscript/polyfills/SetPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/SetPolyfill.java
@@ -13,7 +13,6 @@ import me.topchetoeu.jscript.interop.Native;
 import me.topchetoeu.jscript.interop.NativeGetter;
 
 public class SetPolyfill {
-    @Native("@@Symbol.typeName") public final String name = "Set";
     private LinkedHashSet<Object> set = new LinkedHashSet<>();
 
     @Native("@@Symbol.iterator") public ObjectValue iterator(Context ctx) throws InterruptedException {
diff --git a/src/me/topchetoeu/jscript/polyfills/StringPolyfill.java b/src/me/topchetoeu/jscript/polyfills/StringPolyfill.java
index 41093f5..cab4021 100644
--- a/src/me/topchetoeu/jscript/polyfills/StringPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/StringPolyfill.java
@@ -14,8 +14,6 @@ import me.topchetoeu.jscript.interop.NativeGetter;
 
 // TODO: implement index wrapping properly
 public class StringPolyfill {
-    @Native("@@Symbol.typeName") public final String name = "String";
-
     public final String value;
 
     private static String passThis(Context ctx, String funcName, Object val) throws InterruptedException {
diff --git a/src/me/topchetoeu/jscript/polyfills/SymbolPolyfill.java b/src/me/topchetoeu/jscript/polyfills/SymbolPolyfill.java
index 149b2be..899702c 100644
--- a/src/me/topchetoeu/jscript/polyfills/SymbolPolyfill.java
+++ b/src/me/topchetoeu/jscript/polyfills/SymbolPolyfill.java
@@ -14,7 +14,6 @@ import me.topchetoeu.jscript.interop.NativeGetter;
 
 public class SymbolPolyfill {
     private static final Map<String, Symbol> symbols = new HashMap<>();
-    @Native("@@Symbol.typeName") public final String name = "Symbol";
 
     @NativeGetter public static Symbol typeName(Context ctx) { return ctx.env.symbol("Symbol.typeName"); }
     @NativeGetter public static Symbol replace(Context ctx) { return ctx.env.symbol("Symbol.replace"); }