diff --git a/install.spl b/install.spl
index aa19deb..09899c5 100644
--- a/install.spl
+++ b/install.spl
@@ -4,6 +4,7 @@ func main { mega |
     [ "sudo" "mkdir" "/usr/lib/spl" ] command-wait;
     [ "sh" "-c" "sudo cp *.spl /usr/lib/spl" ] command-wait;
     [ "cargo" "build" "--release" ] command-wait;
+    [ "sudo" "rm" "/bin/spl" ] command-wait;
     [ "sudo" "cp" "target/release/spl" "/bin" ] command-wait;
 
     "make sure its executable";
diff --git a/repl.spl b/repl.spl
new file mode 100644
index 0000000..c900e28
--- /dev/null
+++ b/repl.spl
@@ -0,0 +1,26 @@
+
+func main { mega | with args ;
+    "REPL" =program-name
+    while { 1 } {
+        catch {
+            "  > " print readln dyn-read exec2 "\n" print
+        } 
+        with { with err ;
+            err:message dup null eq if {
+                pop
+                "Uncaught error."
+            } err:trace
+
+            with msg trace ;
+            program-name dup if {
+                program-name print " panicked at:" println
+            } not if {
+                "Program panicked at:" println
+            }
+            &println trace:foreach 
+            "\nPanic message:" println
+            "    " print msg println
+            "\nRecovering." println
+        }
+    }
+}
diff --git a/src/dyn_fns.rs b/src/dyn_fns.rs
index 300008f..35d0c43 100644
--- a/src/dyn_fns.rs
+++ b/src/dyn_fns.rs
@@ -1,7 +1,7 @@
 use std::sync::Arc;
 
-use crate::{lexer, runtime::*};
 use crate::*;
+use crate::{lexer, runtime::*};
 
 pub fn dyn_dump(stack: &mut Stack) -> OError {
     Words {
diff --git a/src/lexer.rs b/src/lexer.rs
index 52d7206..6f6af3e 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -21,6 +21,9 @@ pub fn lex(input: String) -> Result<Words, LexerError> {
 }
 
 fn read_block(str_words: &[String], isfn: bool) -> Result<(Option<u32>, Words, usize), LexerError> {
+    if str_words.len() == 0 {
+        return Ok((None, Words::new(Vec::new()), 0));
+    }
     let mut rem = None;
     let mut words = Vec::new();
     let mut i = 0;
diff --git a/src/std_fns.rs b/src/std_fns.rs
index 41e604f..6f682bf 100644
--- a/src/std_fns.rs
+++ b/src/std_fns.rs
@@ -20,7 +20,12 @@ macro_rules! type_err {
 
 macro_rules! array {
     ($stack:expr, $i:expr) => {
-        || $stack.error(ErrorKind::PropertyNotFound("array".to_owned(), $i.to_string()))
+        || {
+            $stack.error(ErrorKind::PropertyNotFound(
+                "array".to_owned(),
+                $i.to_string(),
+            ))
+        }
     };
 }
 
@@ -511,28 +516,40 @@ pub fn exec(stack: &mut Stack) -> OError {
     };
     unsafe {
         let f = stack.pop_frame(0);
-        let f1 = stack.pop_frame(0);
-        a.to_call.call(stack)?;
-        stack.push_frame(f1);
+        let r = a.to_call.call(stack);
         stack.push_frame(f);
+        r
     }
-    Ok(())
 }
 
 pub fn exec2(stack: &mut Stack) -> OError {
     let Value::Func(a) = stack.pop().lock_ro().native.clone() else {
         return stack.err(ErrorKind::InvalidCall("exec2".to_owned()))
     };
+    unsafe {
+        let f = stack.pop_frame(0);
+        let f1 = stack.pop_frame(0);
+        let r = a.to_call.call(stack);
+        stack.push_frame(f1);
+        stack.push_frame(f);
+        r
+    }
+}
+
+pub fn exec3(stack: &mut Stack) -> OError {
+    let Value::Func(a) = stack.pop().lock_ro().native.clone() else {
+        return stack.err(ErrorKind::InvalidCall("exec3".to_owned()))
+    };
     unsafe {
         let f = stack.pop_frame(0);
         let f1 = stack.pop_frame(0);
         let f2 = stack.pop_frame(0);
-        a.to_call.call(stack)?;
+        let r = a.to_call.call(stack);
         stack.push_frame(f2);
         stack.push_frame(f1);
         stack.push_frame(f);
+        r
     }
-    Ok(())
 }
 
 pub fn stop(stack: &mut Stack) -> OError {
@@ -768,13 +785,23 @@ pub fn acopy(stack: &mut Stack) -> OError {
 }
 
 pub fn throw(stack: &mut Stack) -> OError {
-    let kind = ErrorKind::CustomObject(stack.pop());
-    stack.err(kind)
+    let obj = stack.pop();
+    if let Value::Str(ref s) = obj.lock_ro().native {
+        if obj.lock_ro().kind.lock_ro().get_id()
+            == get_type("str")
+                .expect("str type must exist")
+                .lock_ro()
+                .get_id()
+        {
+            stack.err(ErrorKind::Custom(s.to_owned()))?;
+        }
+    }
+    stack.err(ErrorKind::CustomObject(obj))
 }
 
 pub fn register(r: &mut Stack, o: Arc<Frame>) {
     type Fn = fn(&mut Stack) -> OError;
-    let fns: [(&str, Fn, u32); 50] = [
+    let fns: [(&str, Fn, u32); 51] = [
         ("pop", pop, 0),
         ("dup", dup, 2),
         ("clone", clone, 1),
@@ -812,6 +839,7 @@ pub fn register(r: &mut Stack, o: Arc<Frame>) {
         ("exit", exit, 0),
         ("exec", exec, 0),
         ("exec2", exec2, 0),
+        ("exec3", exec3, 0),
         ("stop", stop, 0),
         ("argv", argv, 1),
         ("get-env", get_env, 1),
diff --git a/std.spl b/std.spl
index 7527e22..c58bf04 100644
--- a/std.spl
+++ b/std.spl
@@ -310,15 +310,13 @@ func concat { str | with a b ;
     a _array b _array aadd _str
 }
 
-func panic { | with msg ;
+func handle-panic { | with msg trace ;
     program-name dup if {
         program-name print " panicked at:" println
     } not if {
         "Program panicked at:" println
     }
-    { | with it ; 
-        it println 
-    } trace:foreach 
+    &println trace:foreach 
     "\nPanic message:" println
     "    " print msg println
     def map env =map
@@ -342,6 +340,8 @@ func panic { | with msg ;
     1 exit
 }
 
+func panic { | trace handle-panic }
+
 { | with msg this ;
     this not if {
         "Assertion failed!" panic
@@ -384,9 +384,17 @@ func -- { mega |
 func _ { | }
 
 func call-main-on-file { | with file ;
-    "@" file concat import 
-    update-types
-    argv main exit
+    catch {
+        "@" file concat import 
+        update-types
+        argv main exit
+    }
+    with { with err ;
+        err:message dup null eq if {
+            pop
+            "Uncaught error."
+        } err:trace handle-panic
+    }
 }
 
 func update-types { | 
diff --git a/test.spl b/test.spl
index 9f225d5..440deec 100644
--- a/test.spl
+++ b/test.spl
@@ -115,7 +115,7 @@ func main { int | with args ;
     catch {
         use net:http:Request
         "testing http" println
-        def req "tudbut.de" 81 "GET" "/" Request:new =req
+        def req "tudbut.de" 81 "GET" "/spltest" Request:new =req
         req:send:body _str println
     } 
     with { with e ;