diff --git a/trixy/trixy-lang_parser/docs/grammar.ebnf b/trixy/trixy-lang_parser/docs/grammar.ebnf
index 05ffca8..abe1be8 100644
--- a/trixy/trixy-lang_parser/docs/grammar.ebnf
+++ b/trixy/trixy-lang_parser/docs/grammar.ebnf
@@ -11,8 +11,9 @@ Function = "fn" Identifier "(" [NamedType {"," NamedType }] ")" [ "->" Type ] ";
 Namespace = "nasp" Identifier "{" {Function | Namespace | Enumeration | Structure} "}" ;
 Structure = "struct" Identifier "{"  [NamedType {"," NamedType } [","]] "}" ";";
 Enumeration = "enum" Identifier "{"  [Identifier {"," Identifier} [","]] "}" ";";
-Identifier = CHARACTER { NUMBER | CHARACTER } ;
+Identifier = (CHARACTER | "_") { NUMBER | CHARACTER | "_" } ;
 NamedType = Identifier ":" Type;
+Type = Identifier ["<" Type {"," Type} ">"];
 
 # (*
 #  vim: ft=ebnf
diff --git a/trixy/trixy-lang_parser/docs/grammar.pdf b/trixy/trixy-lang_parser/docs/grammar.pdf
index bf84bb0..97ec4e9 100644
Binary files a/trixy/trixy-lang_parser/docs/grammar.pdf and b/trixy/trixy-lang_parser/docs/grammar.pdf differ
diff --git a/trixy/trixy-lang_parser/example/full.tri b/trixy/trixy-lang_parser/example/full.tri
index d0ca0b1..9dbebfb 100644
--- a/trixy/trixy-lang_parser/example/full.tri
+++ b/trixy/trixy-lang_parser/example/full.tri
@@ -92,7 +92,7 @@ nasp trinitrix {
             /// Remove a keymapping
             ///
             /// Does nothing, if the keymapping doesn't exists
-            fn remove((/* mode: */ String, /* key: */ String));
+            fn remove(mode: String, key: String);
 
             /// List declared keymappings
             fn get(mode: String);
diff --git a/trixy/trixy-lang_parser/src/command_spec/mod.rs b/trixy/trixy-lang_parser/src/command_spec/mod.rs
index 1bf868c..4b35be6 100644
--- a/trixy/trixy-lang_parser/src/command_spec/mod.rs
+++ b/trixy/trixy-lang_parser/src/command_spec/mod.rs
@@ -1,2 +1,2 @@
-pub mod checked;
+// pub mod checked;
 pub mod unchecked;
diff --git a/trixy/trixy-lang_parser/src/command_spec/unchecked.rs b/trixy/trixy-lang_parser/src/command_spec/unchecked.rs
index c7d2dc5..8c73d50 100644
--- a/trixy/trixy-lang_parser/src/command_spec/unchecked.rs
+++ b/trixy/trixy-lang_parser/src/command_spec/unchecked.rs
@@ -55,7 +55,7 @@ pub enum Genus {
 pub struct Function {
     pub identifier: Token, // Will later become an Identifier
     pub inputs: Vec<NamedType>,
-    pub output: Option<Token>, // Will later become an Type
+    pub output: Option<Type>,
 }
 
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
@@ -73,5 +73,11 @@ pub struct Enumeration {
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct NamedType {
     pub name: Token,   // Will later become an Identifier
-    pub r#type: Token, // Will later become an Type
+    pub r#type: Type,
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Type {
+    pub identifier: Token, // Will later become an Identifier
+    pub generic_args: Vec<Type>,
 }
diff --git a/trixy/trixy-lang_parser/src/error.rs b/trixy/trixy-lang_parser/src/error.rs
index fcf441d..3211a78 100644
--- a/trixy/trixy-lang_parser/src/error.rs
+++ b/trixy/trixy-lang_parser/src/error.rs
@@ -89,7 +89,7 @@ impl ErrorContext {
     pub fn from_index(start: usize, orginal_file: &str) -> Self {
         let span = TokenSpan {
             start,
-            end: start,
+            end: start + 1,
         };
         Self::from_span(span, orginal_file)
     }
diff --git a/trixy/trixy-lang_parser/src/lexing/mod.rs b/trixy/trixy-lang_parser/src/lexing/mod.rs
index a8ecd6c..d77962a 100644
--- a/trixy/trixy-lang_parser/src/lexing/mod.rs
+++ b/trixy/trixy-lang_parser/src/lexing/mod.rs
@@ -121,6 +121,8 @@ pub enum TokenKind {
     BraceClose,
     ParenOpen,
     ParenClose,
+    SquareOpen,
+    SquareClose,
     /// This is not a real TokenKind, but only used for error handling
     Dummy,
 }
@@ -156,6 +158,8 @@ impl Display for TokenKind {
             TokenKind::ParenOpen => f.write_str("PARENOPEN"),
             TokenKind::ParenClose => f.write_str("PARENCLOSE"),
             TokenKind::Dummy => f.write_str("DUMMY"),
+            TokenKind::SquareOpen => f.write_str("SQUAREOPEN"),
+            TokenKind::SquareClose => f.write_str("SQUARECLOSE"),
         }
     }
 }
@@ -211,6 +215,10 @@ macro_rules! token {
     [,]    => { $crate::lexing::TokenKind::Comma };
     [Arrow]    => { $crate::lexing::TokenKind::Arrow };
     [->] => { $crate::lexing::TokenKind::Arrow };
+    [SquareOpen]    => { $crate::lexing::TokenKind::SquareOpen };
+    [<] => { $crate::lexing::TokenKind::SquareOpen };
+    [SquareClose]    => { $crate::lexing::TokenKind::SquareClose };
+    [>] => { $crate::lexing::TokenKind::SquareClose};
     [BraceOpen]    => { $crate::lexing::TokenKind::BraceOpen };
     // [{]    => { $crate::lexing::TokenKind::BraceOpen };
     [BraceClose]    => { $crate::lexing::TokenKind::BraceClose };
diff --git a/trixy/trixy-lang_parser/src/lexing/tokenizer.rs b/trixy/trixy-lang_parser/src/lexing/tokenizer.rs
index 3e78ed7..a4eb885 100644
--- a/trixy/trixy-lang_parser/src/lexing/tokenizer.rs
+++ b/trixy/trixy-lang_parser/src/lexing/tokenizer.rs
@@ -60,8 +60,14 @@ impl<'a> Tokenizer<'a> {
             ':' => (TokenKind::Colon, 1),
             ';' => (TokenKind::Semicolon, 1),
             ',' => (TokenKind::Comma, 1),
+            '<' => (TokenKind::SquareOpen, 1),
+            '>' => (TokenKind::SquareClose, 1),
             '-' => tokenize_arrow(self.remaining_text)?,
-            c @ '_' | c if c.is_alphanumeric() => tokenize_ident(self.remaining_text)?,
+
+            // can't use a OR (`|`) here, as the guard takes precedence
+            c if c.is_alphabetic() => tokenize_ident(self.remaining_text)?,
+            '_' => tokenize_ident(self.remaining_text)?,
+
             other => return Err(LexingError::UnknownCharacter(other)),
         };
 
diff --git a/trixy/trixy-lang_parser/src/parsing/unchecked.rs b/trixy/trixy-lang_parser/src/parsing/unchecked.rs
index 07f9423..a477696 100644
--- a/trixy/trixy-lang_parser/src/parsing/unchecked.rs
+++ b/trixy/trixy-lang_parser/src/parsing/unchecked.rs
@@ -1,6 +1,6 @@
 use crate::{
     command_spec::unchecked::{
-        CommandSpec, Declaration, Enumeration, Function, NamedType, Structure,
+        CommandSpec, Declaration, Enumeration, Function, NamedType, Structure, Type,
     },
     error::ErrorContext,
     lexing::{Token, TokenKind, TokenStream},
@@ -73,6 +73,26 @@ impl Parser {
         }
     }
 
+    fn parse_type(&mut self) -> Result<Type, ParsingError> {
+        let identifier = self.expect(token![Ident])?;
+
+        let mut generic_args = vec![];
+        if self.expect_peek(token![<]) {
+            self.expect(token![<])?;
+            if self.expect_peek(token![Ident]) {
+                generic_args.push(self.parse_type()?);
+            }
+            while self.expect_peek(token![Comma]) {
+                generic_args.push(self.parse_type()?);
+            }
+            self.expect(token![>])?;
+        }
+        Ok(Type {
+            identifier,
+            generic_args,
+        })
+    }
+
     fn parse_namespace(&mut self) -> Result<Vec<Declaration>, ParsingError> {
         self.expect(token![nasp])?;
         let namespace_name = self.expect(token![Ident])?;
@@ -140,7 +160,7 @@ impl Parser {
     fn parse_named_type(&mut self) -> Result<NamedType, ParsingError> {
         let name = self.expect(token![Ident])?;
         self.expect(token![Colon])?;
-        let r#type = self.expect(token![Ident])?;
+        let r#type = self.parse_type()?;
         Ok(NamedType { name, r#type })
     }
 
@@ -162,7 +182,7 @@ impl Parser {
         let mut output_type = None;
         if self.expect_peek(token![->]) {
             self.expect(token![->])?;
-            output_type = Some(self.expect(token![Ident])?);
+            output_type = Some(self.parse_type()?);
         }
         self.expect(token![;])?;
         Ok(Function {