diff --git a/lib/core.ts b/lib/core.ts
index 2dc232a..0199814 100644
--- a/lib/core.ts
+++ b/lib/core.ts
@@ -37,6 +37,7 @@ interface Internals {
 
 var env: Environment = arguments[0], internals: Internals = arguments[1];
 globalThis.log = internals.constructor.log;
+var i = 0.0;
 
 try {
     run('values/object');
diff --git a/lib/values/errors.ts b/lib/values/errors.ts
index 4bfc7e5..a8d1ef0 100644
--- a/lib/values/errors.ts
+++ b/lib/values/errors.ts
@@ -2,11 +2,12 @@ define("values/errors", () => {
     var Error = env.global.Error = function Error(msg: string) {
         if (msg === undefined) msg = '';
         else msg += '';
-    
-        return Object.setPrototypeOf({
+
+        return {
             message: msg,
             stack: [] as string[],
-        }, Error.prototype);
+            __proto__: Error.prototype,
+        } as any;
     } as ErrorConstructor;
 
     setConstr(Error.prototype, Error);
diff --git a/src/me/topchetoeu/jscript/exceptions/EngineException.java b/src/me/topchetoeu/jscript/exceptions/EngineException.java
index 75adb6a..6119a73 100644
--- a/src/me/topchetoeu/jscript/exceptions/EngineException.java
+++ b/src/me/topchetoeu/jscript/exceptions/EngineException.java
@@ -44,8 +44,9 @@ public class EngineException extends RuntimeException {
         return ss.toString();
     }
 
-    private static Object err(String msg, PlaceholderProto proto) {
+    private static Object err(String name, String msg, PlaceholderProto proto) {
         var res = new ObjectValue(proto);
+        if (name != null) res.defineProperty(null, "name", name);
         res.defineProperty(null, "message", msg);
         return res;
     }
@@ -57,19 +58,22 @@ public class EngineException extends RuntimeException {
         this.cause = null;
     }
 
+    public static EngineException ofError(String name, String msg) {
+        return new EngineException(err(name, msg, PlaceholderProto.ERROR));
+    }
     public static EngineException ofError(String msg) {
-        return new EngineException(err(msg, PlaceholderProto.ERROR));
+        return new EngineException(err(null, msg, PlaceholderProto.ERROR));
     }
     public static EngineException ofSyntax(SyntaxException e) {
-        return new EngineException(err(e.msg, PlaceholderProto.SYNTAX_ERROR)).add(null, e.loc);
+        return new EngineException(err(null, e.msg, PlaceholderProto.SYNTAX_ERROR)).add(null, e.loc);
     }
     public static EngineException ofSyntax(String msg) {
-        return new EngineException(err(msg, PlaceholderProto.SYNTAX_ERROR));
+        return new EngineException(err(null, msg, PlaceholderProto.SYNTAX_ERROR));
     }
     public static EngineException ofType(String msg) {
-        return new EngineException(err(msg, PlaceholderProto.TYPE_ERROR));
+        return new EngineException(err(null, msg, PlaceholderProto.TYPE_ERROR));
     }
     public static EngineException ofRange(String msg) {
-        return new EngineException(err(msg, PlaceholderProto.RANGE_ERROR));
+        return new EngineException(err(null, msg, PlaceholderProto.RANGE_ERROR));
     }
 }
diff --git a/src/me/topchetoeu/jscript/filesystem/EntryType.java b/src/me/topchetoeu/jscript/filesystem/EntryType.java
new file mode 100644
index 0000000..26e255a
--- /dev/null
+++ b/src/me/topchetoeu/jscript/filesystem/EntryType.java
@@ -0,0 +1,7 @@
+package me.topchetoeu.jscript.filesystem;
+
+public enum EntryType {
+    NONE,
+    FILE,
+    FOLDER,
+}
\ No newline at end of file
diff --git a/src/me/topchetoeu/jscript/filesystem/File.java b/src/me/topchetoeu/jscript/filesystem/File.java
new file mode 100644
index 0000000..b7a14a8
--- /dev/null
+++ b/src/me/topchetoeu/jscript/filesystem/File.java
@@ -0,0 +1,27 @@
+package me.topchetoeu.jscript.filesystem;
+
+import java.io.IOException;
+
+public interface File {
+    int read() throws IOException, InterruptedException;
+    boolean write(byte val) throws IOException, InterruptedException;
+    long tell() throws IOException, InterruptedException;
+    void seek(long offset, int pos) throws IOException, InterruptedException;
+    void close() throws IOException, InterruptedException;
+    Permissions perms();
+
+    default String readToString() throws IOException, InterruptedException {
+        seek(0, 2);
+        long len = tell();
+        if (len < 0) return null;
+
+        seek(0, 0);
+        byte[] res = new byte[(int)len];
+
+        for (var i = 0; i < len; i++) {
+            res[i] = (byte)read();
+        }
+
+        return new String(res);
+    }
+}
\ No newline at end of file
diff --git a/src/me/topchetoeu/jscript/filesystem/Filesystem.java b/src/me/topchetoeu/jscript/filesystem/Filesystem.java
new file mode 100644
index 0000000..02ae9d5
--- /dev/null
+++ b/src/me/topchetoeu/jscript/filesystem/Filesystem.java
@@ -0,0 +1,10 @@
+package me.topchetoeu.jscript.filesystem;
+
+import java.io.IOException;
+
+public interface Filesystem {
+    File open(String path) throws IOException, InterruptedException;
+    boolean mkdir(String path) throws IOException, InterruptedException;
+    EntryType type(String path) throws IOException, InterruptedException;
+    boolean rm(String path) throws IOException, InterruptedException;
+}
diff --git a/src/me/topchetoeu/jscript/filesystem/InaccessibleFile.java b/src/me/topchetoeu/jscript/filesystem/InaccessibleFile.java
new file mode 100644
index 0000000..2cc59b4
--- /dev/null
+++ b/src/me/topchetoeu/jscript/filesystem/InaccessibleFile.java
@@ -0,0 +1,35 @@
+package me.topchetoeu.jscript.filesystem;
+
+import java.io.IOException;
+
+public class InaccessibleFile implements File {
+    public static final InaccessibleFile INSTANCE = new InaccessibleFile();
+
+    @Override
+    public int read() throws IOException, InterruptedException {
+        return -1;
+    }
+
+    @Override
+    public boolean write(byte val) throws IOException, InterruptedException {
+        return false;
+    }
+
+    @Override
+    public long tell() throws IOException, InterruptedException {
+        return 0;
+    }
+
+    @Override
+    public void seek(long offset, int pos) throws IOException, InterruptedException { }
+
+    @Override
+    public void close() throws IOException, InterruptedException { }
+
+    @Override
+    public Permissions perms() {
+        return Permissions.NONE;
+    }
+
+    private InaccessibleFile() { }
+}
diff --git a/src/me/topchetoeu/jscript/filesystem/MemoryFile.java b/src/me/topchetoeu/jscript/filesystem/MemoryFile.java
new file mode 100644
index 0000000..c414a7e
--- /dev/null
+++ b/src/me/topchetoeu/jscript/filesystem/MemoryFile.java
@@ -0,0 +1,53 @@
+package me.topchetoeu.jscript.filesystem;
+
+import java.io.IOException;
+
+public class MemoryFile implements File {
+    private int ptr;
+    private Permissions mode;
+    public final byte[] data;
+
+    @Override
+    public int read() throws IOException, InterruptedException {
+        if (data == null || !mode.readable || ptr >= data.length) return -1;
+        return data[ptr++];
+    }
+
+    @Override
+    public boolean write(byte val) throws IOException, InterruptedException {
+        if (data == null || !mode.writable || ptr >= data.length) return false;
+        data[ptr++] = val;
+        return true;
+    }
+
+    @Override
+    public long tell() throws IOException, InterruptedException {
+        return ptr;
+    }
+
+    @Override
+    public void seek(long offset, int pos) throws IOException, InterruptedException {
+        if (data == null) return;
+
+        if (pos == 0) ptr = (int)offset;
+        else if (pos == 1) ptr += (int)offset;
+        else if (pos == 2) ptr = data.length - (int)offset;
+    }
+
+    @Override
+    public void close() throws IOException, InterruptedException {
+        mode = null;
+        ptr = 0;
+    }
+
+    @Override
+    public Permissions perms() {
+        if (data == null) return Permissions.NONE;
+        return mode;
+    }
+
+    public MemoryFile(byte[] buff, Permissions mode) {
+        this.data = buff;
+        this.mode = mode;
+    }
+}
diff --git a/src/me/topchetoeu/jscript/filesystem/Permissions.java b/src/me/topchetoeu/jscript/filesystem/Permissions.java
new file mode 100644
index 0000000..5a5ff34
--- /dev/null
+++ b/src/me/topchetoeu/jscript/filesystem/Permissions.java
@@ -0,0 +1,17 @@
+package me.topchetoeu.jscript.filesystem;
+
+public enum Permissions {
+    NONE("", false, false),
+    READ("r", true, false),
+    READ_WRITE("rw", true, true);
+
+    public final String readMode;
+    public final boolean readable;
+    public final boolean writable;
+
+    private Permissions(String mode, boolean r, boolean w) {
+        this.readMode = mode;
+        this.readable = r;
+        this.writable = w;
+    }
+}
diff --git a/src/me/topchetoeu/jscript/filesystem/PhysicalFile.java b/src/me/topchetoeu/jscript/filesystem/PhysicalFile.java
new file mode 100644
index 0000000..cb5d067
--- /dev/null
+++ b/src/me/topchetoeu/jscript/filesystem/PhysicalFile.java
@@ -0,0 +1,51 @@
+package me.topchetoeu.jscript.filesystem;
+
+import java.io.IOException;
+import java.io.RandomAccessFile;
+
+public class PhysicalFile implements File {
+    private RandomAccessFile file;
+    private Permissions perms;
+
+    @Override
+    public int read() throws IOException, InterruptedException {
+        if (file == null || !perms.readable) return -1;
+        else return file.read();
+    }
+
+    @Override
+    public boolean write(byte val) throws IOException, InterruptedException {
+        if (file == null || !perms.writable) return false;
+        file.write(val);
+        return true;
+    }
+
+    @Override
+    public long tell() throws IOException, InterruptedException {
+        if (file == null) return 0;
+        return file.getFilePointer();
+    }
+    @Override
+    public void seek(long offset, int pos) throws IOException, InterruptedException {
+        if (file == null) return;
+        if (pos == 0) file.seek(pos);
+        else if (pos == 1) file.seek(file.getFilePointer() + pos);
+        else if (pos == 2) file.seek(file.length() + pos);
+    }
+
+    @Override
+    public void close() throws IOException, InterruptedException {
+        if (file == null) return;
+        file.close();
+    }
+
+    @Override
+    public Permissions perms() { return perms; }
+    
+    public PhysicalFile(String path, Permissions mode) throws IOException {
+        if (mode == Permissions.NONE) file = null;
+        else file = new RandomAccessFile(path, mode.readMode);
+
+        perms = mode;
+    }
+}
diff --git a/src/me/topchetoeu/jscript/filesystem/PhysicalFilesystem.java b/src/me/topchetoeu/jscript/filesystem/PhysicalFilesystem.java
new file mode 100644
index 0000000..0241676
--- /dev/null
+++ b/src/me/topchetoeu/jscript/filesystem/PhysicalFilesystem.java
@@ -0,0 +1,74 @@
+package me.topchetoeu.jscript.filesystem;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+public class PhysicalFilesystem implements Filesystem {
+    public final Path root;
+
+    private Permissions getPerms(Path path) {
+        var file = path.toFile();
+        if (!path.startsWith(root)) return Permissions.NONE;
+        if (file.canRead() && file.canWrite()) return Permissions.READ_WRITE;
+        if (file.canRead()) return Permissions.READ;
+
+        return Permissions.NONE;
+    }
+    private Path getPath(String name) {
+        return root.resolve(name);
+    }
+
+    @Override
+    public File open(String path) throws IOException, InterruptedException {
+        var _path = root.resolve(path);
+
+        var perms = getPerms(_path);
+        if (perms == Permissions.NONE) return InaccessibleFile.INSTANCE;
+
+        var f = _path.toFile();
+
+        if (f.isDirectory()) {
+            var res = new StringBuilder();
+
+            for (var child : f.listFiles()) res.append(child.toString()).append('\n');
+
+            return new MemoryFile(res.toString().getBytes(), Permissions.READ);
+        }
+        else return new PhysicalFile(path, perms);
+    }
+
+    @Override
+    public boolean mkdir(String path) throws IOException, InterruptedException {
+        var _path = getPath(path);
+        var perms = getPerms(_path);
+        var f = _path.toFile();
+
+        if (!perms.writable) return false;
+        else return f.mkdir();
+    }
+
+    @Override
+    public EntryType type(String path) throws IOException, InterruptedException {
+        var _path = getPath(path);
+        var perms = getPerms(_path);
+        var f = _path.toFile();
+
+        if (perms == Permissions.NONE) return EntryType.NONE;
+        else if (f.isFile()) return EntryType.FILE;
+        else return EntryType.FOLDER;
+    }
+
+    @Override
+    public boolean rm(String path) throws IOException, InterruptedException {
+        var _path = getPath(path);
+        var perms = getPerms(_path);
+        var f = _path.toFile();
+
+        if (!perms.writable) return false;
+        else return f.delete();
+    }
+
+    public PhysicalFilesystem(Path root) {
+        this.root = root;
+    }
+}
diff --git a/src/me/topchetoeu/jscript/parsing/Parsing.java b/src/me/topchetoeu/jscript/parsing/Parsing.java
index cf95238..0672cb5 100644
--- a/src/me/topchetoeu/jscript/parsing/Parsing.java
+++ b/src/me/topchetoeu/jscript/parsing/Parsing.java
@@ -516,12 +516,59 @@ public class Parsing {
 
         for (int i = 2; i < literal.length(); i++) {
             res *= 16;
-            res += fromHex(literal.charAt(i));
+            int dig = fromHex(literal.charAt(i));
+            res += dig;
         }
 
         return res;
     }
 
+    public static Double parseNumber(boolean octals, String value) {
+        if (value.startsWith("0x") || value.startsWith("0X")) {
+            if (value.length() == 2) return null;
+            return parseHex(value);
+        }
+        if (value.endsWith("e") || value.endsWith("E") || value.endsWith("-")) return null;
+
+        int i = 0;
+        double res = 0, dotDivisor = 1;
+        boolean e = false, dot = false;
+        int exponent = 0;
+
+        for (; i < value.length(); i++) {
+            char c = value.charAt(i);
+            if (c == '.') { dot = true; break; }
+            if (c == 'e') { e = true; break; }
+            if (!isDigit(c)) break;
+
+            res = res * 10 + c - '0';
+        }
+
+        if (dot) for (i++; i < value.length(); i++) {
+            char c = value.charAt(i);
+            if (c == 'e') { e = true; break; }
+            if (!isDigit(c)) break;
+
+            res += (c - '0') / (dotDivisor *= 10);
+        }
+
+        if (e) for (i++; i < value.length(); i++) {
+            char c = value.charAt(i);
+            if (!isDigit(c)) break;
+            exponent = 10 * exponent + c - '0';
+        }
+
+        if (exponent < 0) for (int j = 0; j < -exponent; j++) res /= 10;
+        else for (int j = 0; j < exponent; j++) res *= 10;
+
+        return res;
+    }
+    private static double parseNumber(Location loc, String value) {
+        var res = parseNumber(false, value);
+        if (res == null) throw new SyntaxException(loc, "Invalid number format.");
+        else return res;
+    }
+
     private static List<Token> parseTokens(String filename, Collection<RawToken> tokens) {
         var res = new ArrayList<Token>();
 
@@ -529,28 +576,14 @@ public class Parsing {
             var loc = new Location(el.line, el.start, filename);
             switch (el.type) {
                 case LITERAL: res.add(Token.identifier(el.line, el.start, el.value)); break;
-                case NUMBER:
-                    if (el.value.startsWith("0x") || el.value.startsWith("0X")) {
-                        if (el.value.endsWith("x") || el.value.endsWith("X")) {
-                            throw new SyntaxException(loc, "Invalid number format.");
-                        }
-                        res.add(Token.number(el.line, el.start, parseHex(el.value))); break;
-                    }
-                    if (
-                        el.value.endsWith("e") || el.value.endsWith("E") || el.value.endsWith("-")
-                    ) throw new SyntaxException(loc, "Invalid number format.");
-                    else res.add(Token.number(el.line, el.start, Double.parseDouble(el.value))); break;
+                case NUMBER: res.add(Token.number(el.line, el.start, parseNumber(loc, el.value))); break;
+                case STRING: res.add(Token.string(el.line, el.start, parseString(loc, el.value))); break;
+                case REGEX: res.add(Token.regex(el.line, el.start, parseRegex(loc, el.value))); break;
                 case OPERATOR:
                     Operator op = Operator.parse(el.value);
                     if (op == null) throw new SyntaxException(loc, String.format("Unrecognized operator '%s'.", el.value));
                     res.add(Token.operator(el.line, el.start, op));
                     break;
-                case STRING:
-                    res.add(Token.string(el.line, el.start, parseString(loc, el.value)));
-                    break;
-                case REGEX:
-                    res.add(Token.regex(el.line, el.start, parseRegex(loc, el.value)));
-                    break;
             }
         }