diff --git a/linter/src/lib.rs b/linter/src/lib.rs
index eb454ff..64868b0 100644
--- a/linter/src/lib.rs
+++ b/linter/src/lib.rs
@@ -11,6 +11,7 @@ use typetable::*;
 
 type ResultTreeType = Result<(Rc<Box<TypeTree>>, Ty), usize>;
 
+#[derive(Debug)]
 pub struct LintSource<'buf, 'ttb, 'sco> {
     buffer: &'buf str,
     idx: u32,
@@ -124,7 +125,7 @@ impl<'buf, 'ttb, 'sco> LintSource<'buf, 'ttb, 'sco> {
         self.inc_scope_tracker();
         if let Some(args) = td.args.as_ref() {
             args.iter().for_each(|x| {
-                let res = self.lint_recurse(x);
+                let res = self.check_arg_def(&x.into_arg_def());
                 if let Ok(a) = res {
                     largs.push(a.0);
                     largs_curried.push(a.1);
@@ -311,15 +312,14 @@ impl<'buf, 'ttb, 'sco> LintSource<'buf, 'ttb, 'sco> {
     }
 
     pub fn check_value_type(&mut self, _vt: &ValueType) -> ResultTreeType {
-        let mut curried = Ty::Unknown;
-        match _vt.val.token {
-            Token::U64 => curried = Ty::U64,
-            Token::U32 => curried = Ty::U32,
-            Token::USize => curried = Ty::USize,
-            Token::ISize => curried = Ty::ISize,
-            Token::F64 => curried = Ty::F64,
-            Token::U8 => curried = Ty::U8,
-            Token::Char => curried = Ty::Char,
+        let curried = match _vt.val.token {
+            Token::U64 => Ty::U64,
+            Token::U32 => Ty::U32,
+            Token::USize => Ty::USize,
+            Token::ISize => Ty::ISize,
+            Token::F64 => Ty::F64,
+            Token::U8 => Ty::U8,
+            Token::Char => Ty::Char,
             _ => panic!("type lang issue, unmatched value type: {:?}", _vt.val),
         };
         let copied = curried.clone();
@@ -339,24 +339,39 @@ impl<'buf, 'ttb, 'sco> LintSource<'buf, 'ttb, 'sco> {
         let mut c_err: Option<Ty> = None;
         let mut c_undefined: Option<Ty> = None;
         let mut curried = Ty::Unknown;
+        let mut tag = vec![];
 
         if let Some(right) = &_sig.right_most_type {
             c_right = match self.lint_recurse(&right) {
-                Err(_) => Some(Ty::Unknown),
-                Ok(v) => Some(v.1),
+                Err(_) => {
+                    tag.push(Ty::Unknown);
+                    Some(Ty::Unknown)
+                }
+                Ok(v) => {
+                    tag.push(v.1.clone());
+                    Some(v.1)
+                }
             }
         }
         if let Some(left) = &_sig.left_most_type {
             c_left = match self.lint_recurse(&left) {
-                Err(_) => Ty::Unknown,
-                Ok(v) => v.1,
+                Err(_) => {
+                    tag.push(Ty::Unknown);
+                    Ty::Unknown
+                }
+                Ok(v) => {
+                    tag.push(v.1.clone());
+                    v.1
+                }
             }
         }
         if let Some(_) = &_sig.err {
             c_err = Some(Ty::Error);
+            tag.push(Ty::Error);
         }
         if let Some(_) = &_sig.undef {
             c_undefined = Some(Ty::Undefined);
+            tag.push(Ty::Undefined);
         }
         if c_right.is_some() || c_err.is_some() || c_undefined.is_some() {
             sig_info.left = c_left;
@@ -364,12 +379,14 @@ impl<'buf, 'ttb, 'sco> LintSource<'buf, 'ttb, 'sco> {
             sig_info.undefined = c_undefined;
             sig_info.right = c_right;
             let full = tree!(SigTypes, sig_info);
+            curried = Ty::Tag(tag);
 
             return Ok((full, curried));
         }
 
-        let full = tree!(SingleType, c_left);
-        return Ok((full, curried));
+        curried = c_left.clone();
+        let full = tree!(SingleType, curried);
+        return Ok((full, c_left));
     }
 
     pub fn check_self_value(&mut self) -> ResultTreeType {
@@ -835,7 +852,7 @@ impl<'buf, 'ttb, 'sco> LintSource<'buf, 'ttb, 'sco> {
 
                 let tbl = self.ttbls.get_mut(self.curr_scope as usize).unwrap();
 
-                let full: Rc<Box<TypeTree>> = tree!(SelfAccess, a);
+                let full: Rc<Box<TypeTree>> = tree!(SelfInit, a);
                 tbl.table.insert("self".to_string(), Rc::clone(&full));
 
                 return Ok((full, curried));
@@ -1237,6 +1254,24 @@ mod tests {
         assert!(linter.issues.len() == 0);
     }
     #[test]
+    fn it_should_handle_sigs() {
+        const TEST_STR: &'static str = "
+        const val: zerror!?usize = 2
+        const val2: !?usize = 3
+        const val3: ?usize = 4
+        const val4: usize = 5
+        ";
+        let lexer = TLexer::new(TEST_STR);
+        let mut parser = Parser::new(lexer);
+        let result = parser.all();
+        let mut tts = vec![];
+        let mut scps = vec![];
+        let mut linter = LintSource::new(TEST_STR, &mut scps, &mut tts);
+        let _ = linter.lint_check(&result.unwrap());
+
+        assert!(linter.issues.len() == 0);
+    }
+    #[test]
     fn it_should_handle_global_data() {
         const TEST_STR: &'static str = "const val: usize = 2
             const main = fn() void { return 7 + val }
diff --git a/playground.ty b/playground.ty
index d334793..a50f73d 100644
--- a/playground.ty
+++ b/playground.ty
@@ -4,8 +4,8 @@ pub type Motorcycle = struct {
 }
 
 // Data has a type. can be manually declared with : <type>
-const x = 7;
-const y: usize = 7;
+const x = 7
+const y: usize = 7
 
 // Types have types
 // this is usually redundant
@@ -29,7 +29,7 @@ impl Car = trait(Movable) {
 
 // default implementations can be achieved
 pub const set_wheels_default = fn(self: Movable, wheels: u8) void {
-  self.wheels = wheels;
+  self.wheels = wheels
 }
 
 // default implementation