diff --git a/crates/lexer/src/complex_tokens.rs b/crates/lexer/src/complex_tokens.rs
index 802f4ae..52ec7c2 100644
--- a/crates/lexer/src/complex_tokens.rs
+++ b/crates/lexer/src/complex_tokens.rs
@@ -63,23 +63,12 @@ impl Radix {
             Radix::Dec => 10,
         }
     }
-    fn to_token(self) -> Token {
+    fn to_constant_kind(self) -> ConstantKind {
         match self {
-            Radix::Hex => Token::IntegerHexConstant,
-            Radix::Bin => Token::IntegerBinConstant,
-            Radix::Oct => Token::IntegerOctConstant,
-            Radix::Dec => Token::IntegerConstant,
-        }
-    }
-
-    #[expect(dead_code)]
-    pub fn from_token(token: Token) -> Option<Self> {
-        match token {
-            Token::IntegerHexConstant => Some(Radix::Hex),
-            Token::IntegerBinConstant => Some(Radix::Bin),
-            Token::IntegerOctConstant => Some(Radix::Oct),
-            Token::IntegerConstant => Some(Radix::Dec),
-            _ => None,
+            Radix::Hex => ConstantKind::HexInteger,
+            Radix::Bin => ConstantKind::BinInteger,
+            Radix::Oct => ConstantKind::OctInteger,
+            Radix::Dec => ConstantKind::Integer,
         }
     }
 
@@ -236,7 +225,8 @@ fn try_parse_exp_part(source: &mut Source) -> Result<Option<()>> {
 //    DEC_DIGITS FloatingType?
 //    `.` DEC_DIGITS EXP_PART? FloatingType?
 //    DEC_DIGITS `.` DEC_DIGITS? EXP_PART? FloatingType?
-fn parse_constant_inner(source: &mut Source) -> Result<Token> {
+fn parse_constant_inner(source: &mut Source) -> Result<ConstantKind> {
+    let start = source.count;
     let zero = source.next_if(|&c| c == '0').is_some();
 
     let radix = zero
@@ -248,7 +238,7 @@ fn parse_constant_inner(source: &mut Source) -> Result<Token> {
         if source.peek().map(|&c| c == 'u' || c == 'i') == Some(true) {
             try_parse_integral_type(source)?;
         }
-        return Ok(radix.to_token());
+        return Ok(radix.to_constant_kind());
     }
 
     // if zero: `_`* DIGIT (DIGIT|`_`)*
@@ -260,7 +250,7 @@ fn parse_constant_inner(source: &mut Source) -> Result<Token> {
     }?;
 
     if let Some(_) = source.try_map_iter_if(|source| try_parse_integral_type(source))? {
-        return Ok(Token::IntegerConstant);
+        return Ok(ConstantKind::Integer);
     }
 
     let dot = source.next_if(|&c| c == '.').is_some();
@@ -285,17 +275,48 @@ fn parse_constant_inner(source: &mut Source) -> Result<Token> {
     };
 
     let token = match (dot, exp, floating) {
-        (false, false, false) => Token::IntegerConstant,
-        (true, false, _) => Token::DotFloatingConstant,
-        (true, true, _) => Token::DotFloatingExpConstant,
-        (false, true, _) => Token::FloatingExpConstant,
-        (false, _, _) => Token::FloatingConstant,
+        (false, false, false) => ConstantKind::Integer,
+        (true, false, _) => ConstantKind::DotFloating,
+        (true, true, _) => ConstantKind::DotFloatingExp,
+        (false, true, _) => ConstantKind::FloatingExp,
+        (false, _, _) => ConstantKind::Floating,
     };
 
     Ok(token)
 }
 
-pub(crate) fn parse_constant(source: &mut Source) -> Result<Token> {
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ConstantKind {
+    Integer,
+    BinInteger,
+    OctInteger,
+    HexInteger,
+    DotFloating,
+    DotFloatingExp,
+    FloatingExp,
+    Floating,
+    Char,
+    String,
+}
+
+impl<'a> From<(ConstantKind, &'a str)> for Token<'a> {
+    fn from((value, lexeme): (ConstantKind, &'a str)) -> Self {
+        match value {
+            ConstantKind::Integer => Token::IntegerConstant(lexeme),
+            ConstantKind::BinInteger => Token::IntegerBinConstant(lexeme),
+            ConstantKind::OctInteger => Token::IntegerOctConstant(lexeme),
+            ConstantKind::HexInteger => Token::IntegerHexConstant(lexeme),
+            ConstantKind::DotFloating => Token::DotFloatingConstant(lexeme),
+            ConstantKind::DotFloatingExp => Token::DotFloatingExpConstant(lexeme),
+            ConstantKind::FloatingExp => Token::FloatingExpConstant(lexeme),
+            ConstantKind::Floating => Token::FloatingConstant(lexeme),
+            ConstantKind::Char => Token::CharConstant(lexeme),
+            ConstantKind::String => Token::StringConstant(lexeme),
+        }
+    }
+}
+
+pub(crate) fn parse_constant(source: &mut Source) -> Result<ConstantKind> {
     let constant = parse_constant_inner(source)?;
     // char following a constant must not be id_continue
     if source
@@ -309,7 +330,7 @@ pub(crate) fn parse_constant(source: &mut Source) -> Result<Token> {
     Ok(constant)
 }
 
-pub(crate) fn parse_string_or_char_constant(source: &mut Source) -> Result<Token> {
+pub(crate) fn parse_string_or_char_constant(source: &mut Source) -> Result<ConstantKind> {
     let quote = source
         .next_if(|&c| c == '"' || c == '\'')
         .ok_or(Error::InvalidToken)?;
@@ -340,15 +361,64 @@ pub(crate) fn parse_string_or_char_constant(source: &mut Source) -> Result<Token
     }
 
     if is_char {
-        Ok(Token::CharConstant)
+        Ok(ConstantKind::Char)
     } else {
-        Ok(Token::StringConstant)
+        Ok(ConstantKind::String)
     }
 }
 
+/// returns `Ok(true)` if it was a doc comment (///)
+pub(crate) fn parse_comment<'a>(source: &'a mut Source) -> Result<bool> {
+    if !(source.next() == Some('/') && source.next() == Some('/')) {
+        return Err(Error::InvalidToken);
+    }
+
+    let doc = source.next_if_eq(&'/').is_some();
+    eprintln!("doc comment: {doc}");
+    loop {
+        // take until new line
+        source
+            .take_while_inclusive(|&c| c != '\n')
+            .inspect(|c| eprintln!("skipping comment char: {c}"))
+            .for_each(drop);
+
+        let mut copy = source.clone();
+        // skip whitespaces after new line to find continuation of comment
+        (&mut copy)
+            .take_while_ref(|&c| {
+                eprintln!("Skipping whitespace: {c}");
+                is_things::is_whitespace(c) && c != '\n'
+            })
+            .for_each(drop);
+
+        if (copy.next() == Some('/')) && (copy.next() == Some('/')) {
+            match copy.next() {
+                None => break,
+                // docs end here, regular comment starts
+                Some('\n') if doc => break,
+                // this is a comment, so we can just take until this new line
+                Some('\n') if !doc => continue,
+                // continue doc comment
+                Some('/') if doc => {}
+                Some('/') if !doc => break,
+                Some(_) if doc => break,
+                // continue regular comment
+                Some(_) => {}
+            }
+
+            *source = copy;
+        } else {
+            break;
+        }
+    }
+    Ok(doc)
+}
+
 #[cfg(test)]
 mod tests {
 
+    use crate::complex_tokens::parse_comment;
+
     use super::*;
 
     fn make_source(s: &'_ str) -> Source<'_> {
@@ -359,36 +429,36 @@ mod tests {
     fn parse_constant_number() {
         assert_eq!(
             parse_constant(&mut make_source("0x1A3F_u32")),
-            Ok(Token::IntegerHexConstant)
+            Ok(ConstantKind::HexInteger)
         );
         assert_eq!(
             parse_constant(&mut make_source("13f32")),
-            Ok(Token::FloatingConstant)
+            Ok(ConstantKind::Floating)
         );
 
         assert_eq!(
             parse_constant(&mut make_source("0b1011_0010i16")),
-            Ok(Token::IntegerBinConstant)
+            Ok(ConstantKind::BinInteger)
         );
         assert_eq!(
             parse_constant(&mut make_source("0o755u8")),
-            Ok(Token::IntegerOctConstant)
+            Ok(ConstantKind::OctInteger)
         );
         assert_eq!(
             parse_constant(&mut make_source("42i64")),
-            Ok(Token::IntegerConstant)
+            Ok(ConstantKind::Integer)
         );
         assert_eq!(
             parse_constant(&mut make_source("3.14f64")),
-            Ok(Token::DotFloatingConstant)
+            Ok(ConstantKind::DotFloating)
         );
         assert_eq!(
             parse_constant(&mut make_source("2.71828e0f32")),
-            Ok(Token::DotFloatingExpConstant)
+            Ok(ConstantKind::DotFloatingExp)
         );
         assert_eq!(
             parse_constant(&mut make_source("22e23")),
-            Ok(Token::FloatingExpConstant)
+            Ok(ConstantKind::FloatingExp)
         );
     }
 }
diff --git a/crates/lexer/src/lib.rs b/crates/lexer/src/lib.rs
index dfcbb9b..2b996ea 100644
--- a/crates/lexer/src/lib.rs
+++ b/crates/lexer/src/lib.rs
@@ -91,47 +91,47 @@ macro_rules! tokens {
 
             #[allow(dead_code)]
             #[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
-            $vis enum $ty_name {
+            $vis enum $ty_name<'a> {
                 $($name,
                 )*
-                $($name2,)*
+                $($name2(&'a str),)*
             }
 
-            impl ::core::fmt::Display for $ty_name {
+            impl ::core::fmt::Display for $ty_name<'_> {
                 fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
                     match self {
                         $(Self::$name => write!(f, "{}", $lexeme),)*
-                        $(Self::$name2 => write!(f, "<{}>", stringify!($name2))),*
+                        $(Self::$name2(lexeme) => write!(f, "[{}: {lexeme}]", stringify!($name2))),*
                     }
                 }
             }
 
             #[allow(dead_code)]
-            impl $ty_name {
-                $vis fn lexeme(&self) -> Option<&'static str> {
+            impl $ty_name<'_> {
+                $vis fn lexeme(&'_ self) -> &'_ str {
                     match self {
-                        $(Self::$name => Some($lexeme),)*
-                        $(Self::$name2 => None),*
+                        $(Self::$name => $lexeme,)*
+                        $(Self::$name2(lexeme) => lexeme),*
                     }
                 }
 
                 /// returns the number of chars in this lexeme
                 $vis fn lexeme_len(&self) -> usize {
-                    self.lexeme().map(|lexeme|lexeme.chars().count()).unwrap_or(0)
+                    self.lexeme().chars().count()
                 }
 
                 /// returns the number of chars in this lexeme
                 $vis fn lexeme_len_utf8(&self) -> usize {
-                    self.lexeme().map(|lexeme|lexeme.len()).unwrap_or(0)
+                    self.lexeme().len()
                 }
 
                 $vis fn maybe_ident(&self) -> bool {
-                    self.lexeme().map(|lexeme| crate::is_things::is_ident(lexeme)).unwrap_or(false)
+                    crate::is_things::is_ident(self.lexeme())
                 }
 
-                $vis fn lexemes() -> &'static [(Self, &'static str)] {
+                $vis fn lexemes() -> &'static [(Token<'static>, &'static str)] {
                     &[
-                        $((Self::$name, $lexeme)),*
+                        $((Token::$name, $lexeme)),*
                     ]
                 }
             }
@@ -159,8 +159,8 @@ tokens!(pub Token: {
 },
     // Lexical Tokens:
     {
-        SlashSlash => "//",
-        SlashSlashSlash => "///",
+        // SlashSlash => "//",
+        // SlashSlashSlash => "///",
         // SlashStar => "/*",
         // SlashStarStar => "/**",
         //StarSlash => "*/",
@@ -251,7 +251,7 @@ tokens!(pub Token: {
         GreaterGreaterEqual => ">>="
     });
 
-impl Token {
+impl Token<'_> {
     pub fn is_assignment_op(self) -> bool {
         match self {
             Token::PlusEqual
@@ -299,18 +299,13 @@ impl Token {
     }
 }
 
-use std::{
-    collections::VecDeque,
-    marker::PhantomData,
-    ops::{Deref, DerefMut, Range},
-};
+use std::{marker::PhantomData, ops::Range};
 
 use trie::Tree;
 
 #[derive(Debug, Clone, Copy)]
 pub struct TokenItem<'a> {
-    pub token: Token,
-    pub lexeme: &'a str,
+    pub token: Token<'a>,
     pub offset: u32,
 }
 
@@ -340,24 +335,39 @@ impl<I: Iterator> CharCountingIterator<I> {
     }
 }
 
-impl<I: Iterator> core::ops::Deref for CharCountingIterator<I> {
-    type Target = I;
+impl<I: Iterator<Item = char>> CharCountingIterator<core::iter::Peekable<I>> {
+    fn peek(&mut self) -> Option<&I::Item> {
+        self.iter.peek()
+    }
 
-    fn deref(&self) -> &Self::Target {
-        &self.iter
+    fn next_if_eq(&mut self, expected: &I::Item) -> Option<I::Item>
+    where
+        I::Item: PartialEq,
+    {
+        self.iter
+            .next_if_eq(expected)
+            .inspect(|c| self.count += c.len_utf8())
     }
 }
 
-impl<I: Iterator> core::ops::DerefMut for CharCountingIterator<I> {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.iter
-    }
-}
+// impl<I: Iterator> core::ops::Deref for CharCountingIterator<I> {
+//     type Target = I;
+
+//     fn deref(&self) -> &Self::Target {
+//         &self.iter
+//     }
+// }
+
+// impl<I: Iterator> core::ops::DerefMut for CharCountingIterator<I> {
+//     fn deref_mut(&mut self) -> &mut Self::Target {
+//         &mut self.iter
+//     }
+// }
 
 type Source<'a> = CharCountingIterator<core::iter::Peekable<core::str::Chars<'a>>>;
 
 pub struct TokenIterator<'a> {
-    trie: Tree<char, Token>,
+    trie: Tree<char, Token<'static>>,
     source: &'a str,
     offset: usize,
 }
@@ -381,7 +391,7 @@ impl<'a> TokenIterator<'a> {
         CharCountingIterator::from(self.source[self.offset..].chars().peekable())
     }
 
-    fn parse(&mut self) -> Option<Token> {
+    fn parse(&mut self) -> Option<Token<'static>> {
         let mut iter = CharCountingIterator::from(self.source[self.offset..].chars());
 
         match self.trie.get_closest(&mut iter) {
@@ -423,7 +433,11 @@ impl<'a> TokenIterator<'a> {
         count
     }
 
-    fn next_token(&mut self) -> Option<(Token, Range<usize>)> {
+    fn follows(&self, s: &str) -> bool {
+        self.source[self.offset..].starts_with(s)
+    }
+
+    fn next_token(&mut self) -> Option<(Token<'a>, Range<usize>)> {
         // skip whitespace
         self.skip_whitespaces();
 
@@ -436,19 +450,19 @@ impl<'a> TokenIterator<'a> {
                 let token = complex_tokens::parse_constant(&mut source).ok()?;
                 self.offset += source.offset();
 
-                Some(token)
+                Some((token, &self.source[start..self.offset]).into())
             }
             Some('.') if cursor.next().map_or(false, is_things::is_digit) => {
                 let token = complex_tokens::parse_constant(&mut source).ok()?;
                 self.offset += source.offset();
 
-                Some(token)
+                Some((token, &self.source[start..self.offset]).into())
             }
             Some('\'' | '"') => {
                 let token = complex_tokens::parse_string_or_char_constant(&mut source).ok()?;
                 self.offset += source.offset();
 
-                Some(token)
+                Some((token, &self.source[start..self.offset]).into())
             }
             Some('`') => {
                 // raw identifier
@@ -456,27 +470,32 @@ impl<'a> TokenIterator<'a> {
                 self.skip_while(|c| is_things::is_id_continue(c));
                 if self.peekable_source().next() == Some('`') {
                     self.skip(1);
-                    Some(Token::Ident)
+                    let lexeme = &self.source[start..self.offset];
+                    Some(Token::Ident(lexeme))
                 } else {
                     // unterminated raw identifier
-                    Some(Token::ParseError)
+                    let lexeme = &self.source[start..self.offset];
+                    Some(Token::ParseError(lexeme))
                 }
             }
             // `//`-style comments or doc-comments
-            _ => match self.parse().map(|tok| match tok {
-                Token::SlashSlash => {
-                    self.skip_while(|c| c == '\n');
-                    Token::Comment
+            Some('/') if self.follows("//") => {
+                let doc = complex_tokens::parse_comment(&mut source).ok()?;
+                self.offset += source.offset();
+                eprintln!("next: {:?}", source.next());
+                eprintln!("rest: {:?}", &self.source[self.offset..]);
+
+                let lexeme = &self.source[start..self.offset];
+                if doc {
+                    Some(Token::DocComment(lexeme))
+                } else {
+                    Some(Token::Comment(lexeme))
                 }
-                Token::SlashSlashSlash => {
-                    self.skip_while(|c| c == '\n');
-                    Token::DocComment
-                }
-                _ => tok,
-            }) {
+            }
+            _ => match self.parse() {
                 Some(tok) => {
                     if tok.maybe_ident() && self.skip_while(|c| is_things::is_id_continue(c)) > 0 {
-                        Some(Token::Ident)
+                        Some(Token::Ident(&self.source[start..self.offset]))
                     } else {
                         Some(tok)
                     }
@@ -489,7 +508,7 @@ impl<'a> TokenIterator<'a> {
                     {
                         self.skip(1);
                         self.skip_while(|c| is_things::is_id_continue(c));
-                        Some(Token::Ident)
+                        Some(Token::Ident(&self.source[start..self.offset]))
                     } else {
                         None
                     }
@@ -502,10 +521,8 @@ impl<'a> TokenIterator<'a> {
 
     fn next_token_item(&mut self) -> Option<TokenItem<'a>> {
         let (token, range) = self.next_token()?;
-        let lexeme = &self.source[range.clone()];
         Some(TokenItem {
             token,
-            lexeme,
             offset: range.start as u32,
         })
     }
@@ -516,7 +533,7 @@ impl<'a> TokenIterator<'a> {
 }
 
 impl<'a> Iterator for TokenIterator<'a> {
-    type Item = Token;
+    type Item = Token<'a>;
 
     fn next(&mut self) -> Option<Self::Item> {
         self.next_token().map(|(token, _)| token)
@@ -535,115 +552,6 @@ impl<'a> Iterator for TokenItemIterator<'a> {
     }
 }
 
-pub struct Peeking;
-pub struct Consuming;
-pub trait ReborrowMode: sealed::Sealed {}
-impl ReborrowMode for Peeking {}
-impl ReborrowMode for Consuming {}
-
-mod sealed {
-    pub trait Sealed {}
-    impl Sealed for super::Peeking {}
-    impl Sealed for super::Consuming {}
-}
-
-enum Queue<'a, T> {
-    Owned(VecDeque<T>),
-    Borrowed(&'a mut VecDeque<T>),
-}
-
-impl<'a, T> Queue<'a, T> {
-    fn borrowed(&'_ mut self) -> Queue<'_, T> {
-        match self {
-            Queue::Owned(v) => Queue::Borrowed(v),
-            Queue::Borrowed(v) => Queue::Borrowed(v),
-        }
-    }
-}
-
-impl<T> Deref for Queue<'_, T> {
-    type Target = VecDeque<T>;
-
-    fn deref(&self) -> &Self::Target {
-        match self {
-            Queue::Owned(v) => v,
-            Queue::Borrowed(v) => v,
-        }
-    }
-}
-
-impl<T> DerefMut for Queue<'_, T> {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        match self {
-            Queue::Owned(v) => v,
-            Queue::Borrowed(v) => v,
-        }
-    }
-}
-
-pub struct ReborrowingIterator<'a, 'b, I, T, Marker>
-where
-    I: Iterator<Item = T>,
-{
-    iter: &'a mut I,
-    cache: Queue<'b, T>,
-    peeking_cursor: usize,
-    _marker: PhantomData<Marker>,
-}
-
-pub type ReborrowingPeekingIterator<'a, 'b, I, T> = ReborrowingIterator<'a, 'b, I, T, Peeking>;
-pub type ReborrowingConsumingIterator<'a, 'b, I, T> = ReborrowingIterator<'a, 'b, I, T, Consuming>;
-
-impl<'a, 'b, I, T, Marker> ReborrowingIterator<'a, 'b, I, T, Marker>
-where
-    I: Iterator<Item = T>,
-{
-    pub fn new(iter: &'a mut I) -> Self {
-        Self {
-            iter,
-            cache: Queue::Owned(VecDeque::new()),
-            peeking_cursor: 0,
-            _marker: PhantomData,
-        }
-    }
-
-    pub fn reborrow_peeking(self) -> ReborrowingIterator<'a, 'b, I, T, Peeking> {
-        ReborrowingIterator {
-            iter: self.iter,
-            cache: self.cache,
-            peeking_cursor: 0,
-            _marker: PhantomData,
-        }
-    }
-
-    pub fn reborrow_consuming(self) -> ReborrowingIterator<'a, 'b, I, T, Consuming> {
-        ReborrowingIterator {
-            iter: self.iter,
-            cache: self.cache,
-            peeking_cursor: 0,
-            _marker: PhantomData,
-        }
-    }
-
-    pub fn borrow_peeking(&'_ mut self) -> ReborrowingIterator<'_, '_, I, T, Peeking> {
-        ReborrowingIterator {
-            iter: self.iter,
-            cache: self.cache.borrowed(),
-            peeking_cursor: 0,
-            _marker: PhantomData,
-        }
-    }
-
-    pub fn borrow_consuming(&'_ mut self) -> ReborrowingIterator<'_, '_, I, T, Consuming> {
-        ReborrowingIterator {
-            iter: self.iter,
-            cache: self.cache.borrowed(),
-            peeking_cursor: 0,
-            _marker: PhantomData,
-        }
-    }
-}
-
 pub trait TokenConsumer<'a> {
     type Product;
     type Error;
@@ -732,34 +640,34 @@ where
 }
 
 pub trait TokenSequence {
-    fn tokens(&'_ self) -> &'_ [Token];
+    fn tokens(&'_ self) -> &'_ [Token<'_>];
 }
 
-impl TokenSequence for Token {
-    fn tokens(&'_ self) -> &'_ [Token] {
+impl TokenSequence for Token<'_> {
+    fn tokens(&'_ self) -> &'_ [Token<'_>] {
         std::slice::from_ref(self)
     }
 }
-impl TokenSequence for [Token] {
-    fn tokens(&'_ self) -> &'_ [Token] {
+impl TokenSequence for [Token<'_>] {
+    fn tokens(&'_ self) -> &'_ [Token<'_>] {
         self
     }
 }
-impl TokenSequence for &[Token] {
-    fn tokens(&'_ self) -> &'_ [Token] {
+impl TokenSequence for &[Token<'_>] {
+    fn tokens(&'_ self) -> &'_ [Token<'_>] {
         self
     }
 }
 
-impl<const N: usize> TokenSequence for [Token; N] {
-    fn tokens(&'_ self) -> &'_ [Token] {
+impl<const N: usize> TokenSequence for [Token<'_>; N] {
+    fn tokens(&'_ self) -> &'_ [Token<'_>] {
         self
     }
 }
 
 pub trait TokenSequenceList {
     fn for_each(&mut self, f: impl FnMut(&dyn TokenSequence));
-    fn iter_sequences(&self) -> impl Iterator<Item = &[Token]>;
+    fn iter_sequences(&'_ self) -> impl Iterator<Item = &[Token<'_>]>;
     fn first<T>(&mut self, pred: impl FnMut(&dyn TokenSequence) -> Option<T>) -> Option<T>;
 }
 impl<T: TokenSequence> TokenSequenceList for T {
@@ -767,7 +675,7 @@ impl<T: TokenSequence> TokenSequenceList for T {
         f(self);
     }
 
-    fn iter_sequences(&self) -> impl Iterator<Item = &[Token]> {
+    fn iter_sequences(&'_ self) -> impl Iterator<Item = &[Token<'_>]> {
         std::iter::once(self.tokens())
     }
 
@@ -785,7 +693,7 @@ macro_rules! impl_token_sequence_list {
                 $(self.$is.for_each(&mut f);)*
             }
 
-            fn iter_sequences(&self) -> impl Iterator<Item = &[Token]> {
+            fn iter_sequences(&'_ self) -> impl Iterator<Item = &[Token<'_>]> {
                 std::iter::empty()
                 $(.chain(self.$is.iter_sequences()))*
             }
@@ -803,151 +711,6 @@ macro_rules! impl_token_sequence_list {
 }
 
 variadics_please::all_tuples_enumerated!(impl_token_sequence_list, 1, 15, T);
-
-impl<'a, 'b, I> ReborrowingIterator<'a, 'b, I, TokenItem<'a>, Consuming>
-where
-    I: Iterator<Item = TokenItem<'a>>,
-{
-    pub fn expect_one_of<Ts: IntoIterator<Item = Token>>(
-        &mut self,
-        candidates: Ts,
-    ) -> Option<TokenItem<'a>> {
-        let mut candidates = candidates.into_iter();
-
-        let item = self.next()?;
-        if candidates.any(|cand| cand == item.token) {
-            Some(item)
-        } else {
-            None
-        }
-    }
-
-    pub fn expect_sequence<S: TokenSequence + ?Sized>(
-        &mut self,
-        sequence: &S,
-    ) -> Option<Vec<TokenItem<'a>>> {
-        let ref mut peeking = self.borrow_peeking();
-
-        // check that the next tokens match the expected sequence
-        let matches = sequence
-            .tokens()
-            .into_iter()
-            .copied()
-            .zip(peeking.map(|item| item.token))
-            .all(|(a, b)| a == b);
-        if matches {
-            Some(peeking.drain_peeked().collect())
-        } else {
-            None
-        }
-    }
-
-    pub fn expect_sequence_list<L: TokenSequenceList>(&mut self, mut list: L) {
-        list.first(|s| self.expect_sequence(s));
-    }
-}
-
-impl<'a, 'b, I, T> Iterator for ReborrowingIterator<'a, 'b, I, T, Consuming>
-where
-    I: Iterator<Item = T>,
-{
-    type Item = T;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        self.cache.pop_front().or_else(|| self.iter.next())
-    }
-}
-
-impl<'a, 'b, I, T> Iterator for ReborrowingIterator<'a, 'b, I, T, Peeking>
-where
-    I: Iterator<Item = T>,
-    T: Copy,
-{
-    type Item = T;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        self.peek_next().copied()
-    }
-}
-
-impl<'a, 'b, I, T> ReborrowingIterator<'a, 'b, I, T, Peeking>
-where
-    I: Iterator<Item = T>,
-{
-    pub fn peek_next(&mut self) -> Option<&T> {
-        if self.peeking_cursor >= self.cache.len() {
-            if let Some(item) = self.iter.next() {
-                self.peeking_cursor += 1;
-                Some(self.cache.push_back_mut(item))
-            } else {
-                None
-            }
-        } else {
-            let item = self.cache.get(self.peeking_cursor)?;
-            self.peeking_cursor += 1;
-            Some(item)
-        }
-    }
-
-    pub fn drain_peeked(&mut self) -> impl Iterator<Item = T> + '_ {
-        let drained = self.cache.drain(0..self.peeking_cursor);
-        self.peeking_cursor = 0;
-        drained
-    }
-
-    pub fn skip(&mut self, n: usize) {
-        let cached = self.cache.len() - self.peeking_cursor;
-        self.peeking_cursor = self.peeking_cursor.saturating_add(n);
-        if n > cached {
-            // need to pull from the underlying iterator
-            let surplus = n - cached;
-            self.cache.extend(self.iter.take(surplus));
-            self.peeking_cursor += n;
-        }
-    }
-
-    pub fn borrow_consuming_at_cursor(
-        &'_ mut self,
-    ) -> ReborrowingIterator<'_, '_, I, T, Consuming> {
-        _ = self.drain_peeked();
-        ReborrowingIterator {
-            iter: self.iter,
-            cache: self.cache.borrowed(),
-            peeking_cursor: 0,
-            _marker: PhantomData,
-        }
-    }
-
-    pub fn reborrow_consuming_at_cursor(mut self) -> ReborrowingIterator<'a, 'b, I, T, Consuming> {
-        _ = self.drain_peeked();
-        ReborrowingIterator {
-            iter: self.iter,
-            cache: self.cache,
-            peeking_cursor: 0,
-            _marker: PhantomData,
-        }
-    }
-}
-
-impl<'a, 'b, I> ReborrowingIterator<'a, 'b, I, TokenItem<'a>, Peeking>
-where
-    I: Iterator<Item = TokenItem<'a>>,
-{
-    pub fn peek_one_of<Ts: IntoIterator<Item = Token>>(
-        &mut self,
-        candidates: Ts,
-    ) -> Option<TokenItem<'a>> {
-        let mut candidates = candidates.into_iter();
-
-        let item = self.peek_next()?;
-        if candidates.any(|cand| cand == item.token) {
-            Some(*item)
-        } else {
-            None
-        }
-    }
-}
-
 mod complex_tokens;
 
 #[cfg(test)]
@@ -972,7 +735,7 @@ mod tests {
     #[test]
     fn idents() {
         let mut lexer = TokenIterator::new("a a1 a_ a-b _a _1 _- -a -1 -_ `123");
-        assert!(lexer.all(|tok| tok == Token::Ident));
+        assert!(lexer.all(|tok| matches!(tok, Token::Ident(_))));
     }
 
     #[test]
@@ -982,43 +745,61 @@ mod tests {
         assert_eq!(
             tokens,
             vec![
-                Token::Ident,
-                Token::Ident,
+                Token::Ident("a-a"),
+                Token::Ident("a-"),
                 Token::Minus,
-                Token::Ident,
-                Token::Ident,
-                Token::Ident
+                Token::Ident("a"),
+                Token::Ident("-a"),
+                Token::Ident("--a")
             ]
         );
     }
 
+    #[test]
+    fn comments() {
+        let mut lexer = TokenIterator::new(
+            r#"
+// this is a comment
+// spanning two lines
+/// this is a doc comment"#,
+        );
+        assert_eq!(
+            lexer.next(),
+            Some(Token::Comment(
+                "// this is a comment\n// spanning two lines\n"
+            ))
+        );
+        assert_eq!(
+            lexer.next(),
+            Some(Token::DocComment("/// this is a doc comment"))
+        );
+    }
+
     #[test]
     fn complex_iterator() {
         let tokens = "fn my-function(x: i32, y: f32) -> f32 { return x + y; }";
         let lexer = TokenIterator::new(&tokens);
-        let mut items = lexer
-            .into_token_items()
-            .map(|item| (item.token, item.lexeme));
-        assert_eq!(items.next(), Some((Token::Fn, "fn")));
-        assert_eq!(items.next(), Some((Token::Ident, "my-function")));
-        assert_eq!(items.next(), Some((Token::OpenParens, "(")));
-        assert_eq!(items.next(), Some((Token::Ident, "x")));
-        assert_eq!(items.next(), Some((Token::Colon, ":")));
-        assert_eq!(items.next(), Some((Token::I32, "i32")));
-        assert_eq!(items.next(), Some((Token::Comma, ",")));
-        assert_eq!(items.next(), Some((Token::Ident, "y")));
-        assert_eq!(items.next(), Some((Token::Colon, ":")));
-        assert_eq!(items.next(), Some((Token::F32, "f32")));
-        assert_eq!(items.next(), Some((Token::CloseParens, ")")));
-        assert_eq!(items.next(), Some((Token::MinusGreater, "->")));
-        assert_eq!(items.next(), Some((Token::F32, "f32")));
-        assert_eq!(items.next(), Some((Token::OpenBrace, "{")));
-        assert_eq!(items.next(), Some((Token::Return, "return")));
-        assert_eq!(items.next(), Some((Token::Ident, "x")));
-        assert_eq!(items.next(), Some((Token::Plus, "+")));
-        assert_eq!(items.next(), Some((Token::Ident, "y")));
-        assert_eq!(items.next(), Some((Token::Semi, ";")));
-        assert_eq!(items.next(), Some((Token::CloseBrace, "}")));
+        let mut items = lexer.into_token_items().map(|item| item.token);
+        assert_eq!(items.next(), Some(Token::Fn));
+        assert_eq!(items.next(), Some(Token::Ident("my-function")));
+        assert_eq!(items.next(), Some(Token::OpenParens));
+        assert_eq!(items.next(), Some(Token::Ident("x")));
+        assert_eq!(items.next(), Some(Token::Colon));
+        assert_eq!(items.next(), Some(Token::I32));
+        assert_eq!(items.next(), Some(Token::Comma));
+        assert_eq!(items.next(), Some(Token::Ident("y")));
+        assert_eq!(items.next(), Some(Token::Colon));
+        assert_eq!(items.next(), Some(Token::F32));
+        assert_eq!(items.next(), Some(Token::CloseParens));
+        assert_eq!(items.next(), Some(Token::MinusGreater));
+        assert_eq!(items.next(), Some(Token::F32));
+        assert_eq!(items.next(), Some(Token::OpenBrace));
+        assert_eq!(items.next(), Some(Token::Return));
+        assert_eq!(items.next(), Some(Token::Ident("x")));
+        assert_eq!(items.next(), Some(Token::Plus));
+        assert_eq!(items.next(), Some(Token::Ident("y")));
+        assert_eq!(items.next(), Some(Token::Semi));
+        assert_eq!(items.next(), Some(Token::CloseBrace));
         assert_eq!(items.next(), None);
     }
 }
diff --git a/crates/parser/src/lib.rs b/crates/parser/src/lib.rs
index 885462d..395da7d 100644
--- a/crates/parser/src/lib.rs
+++ b/crates/parser/src/lib.rs
@@ -1,12 +1,15 @@
 use internment::Intern;
-use lexer::{
-    Consuming, ReborrowingConsumingIterator, ReborrowingIterator, ReborrowingPeekingIterator,
-    Token, TokenConsumer, TokenItem, TokenItemIterator,
-};
+use lexer::{Token, TokenConsumer, TokenItem, TokenItemIterator};
 use logos::Logos;
 use pomelo::pomelo;
 use thiserror::Error;
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum IntSize {
+    Bits(u16),
+    Pointer,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum InnerType {
     Top,
@@ -15,7 +18,7 @@ pub enum InnerType {
     Bool,
     Int {
         signed: bool,
-        bits: u8,
+        size: IntSize,
     },
     Float {
         float_type: FloatType,
@@ -98,7 +101,8 @@ pub enum AstNode {
         ty: Type,
         value: Value,
     },
-    ExpressionStatement {
+    NoopExpr,
+    Stmt {
         expr: Index,
     },
     ControlFlow {
@@ -249,17 +253,33 @@ pub enum AstNode {
     Else {
         expr: Index,
     },
+    Comment {
+        text: String,
+    },
+    Attributes {
+        attrs: Vec<Index>,
+    },
+    Doc {
+        text: String,
+    },
     Error {
         err: Box<dyn core::error::Error>,
     },
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default)]
+pub enum Visibility {
+    #[default]
+    Private,
+    Public,
+}
+
 #[derive(Debug, Error)]
-pub enum ParseError {
+pub enum ParseError<'a> {
     #[error("End of file.")]
     EOF,
     #[error("Unexpected token: {0:?}")]
-    UnexpectedToken(Token),
+    UnexpectedToken(Token<'a>),
     #[error("Not a type.")]
     NotAType,
 }
@@ -283,6 +303,7 @@ impl Ast {
 #[derive(Debug)]
 struct FunctionDecl {
     name: String,
+    visibility: Visibility,
     return_type: Type,
     parameter_list: Option<ParameterList>,
     body: Index,
@@ -290,6 +311,7 @@ struct FunctionDecl {
 
 #[derive(Debug)]
 struct Parameter {
+    mutable: bool,
     name: String,
     param_type: Type,
 }
@@ -310,41 +332,86 @@ pomelo! {
         use super::AstNode;
         use super::{
             Parameter, Ast, ParameterList, FunctionDecl, Type, InnerType,
-            FloatType, ExtraToken, Index,
+            FloatType, ExtraToken, Index, IntSize, Visibility,
         };
     };
     %extra_argument Ast;
     %parser pub struct Parser<'a>{};
-    %extra_token (&'a str, u32);
+    %token #[derive(Debug)] pub enum Token<'a> {};
+    // %default_type &'a str;
+    %type Ident &'a str;
+    %type DocComment &'a str;
+    %type Comment &'a str;
     %type fn_decl FunctionDecl;
     %type parameter Parameter;
     %type parameter_list ParameterList;
     %type typ Type;
     %type return_type Type;
     %type block Index;
+    %type decl Index;
+    %type decl_list Vec<Index>;
+    %type file Index;
 
-    file ::= decl_list?;
-    decl_list ::= decl;
-    decl_list ::= decl_list decl;
+    file ::= decl_list?(list) {
+        let decls = list.unwrap_or_default();
+        extra.push(AstNode::File { decls })
+    };
+    decl_list ::= decl(decl) { vec![decl] };
+    decl_list ::= decl_list(dl) decl(decl) {
+        let mut list = dl;
+        list.push(decl);
+        list
+    };
 
     typ ::= Bool { internment::Intern::new(InnerType::Bool) };
-    typ ::= I8 { internment::Intern::new(InnerType::Int { signed: true, bits: 8 }) };
-    typ ::= I16 { internment::Intern::new(InnerType::Int { signed: true, bits: 16 }) };
-    typ ::= I32 { internment::Intern::new(InnerType::Int { signed: true, bits: 32 }) };
-    typ ::= I64 { internment::Intern::new(InnerType::Int { signed: true, bits: 64 }) };
-    typ ::= U8 { internment::Intern::new(InnerType::Int { signed: false, bits: 8 }) };
-    typ ::= U16 { internment::Intern::new(InnerType::Int { signed: false, bits: 16 }) };
-    typ ::= U32 { internment::Intern::new(InnerType::Int { signed: false, bits: 32 }) };
-    typ ::= U64 { internment::Intern::new(InnerType::Int { signed: false, bits: 64 }) };
+    typ ::= I1 { internment::Intern::new(InnerType::Int { signed: true, size: IntSize::Bits(1) }) };
+    typ ::= I8 { internment::Intern::new(InnerType::Int { signed: true, size: IntSize::Bits(8) }) };
+    typ ::= I16 { internment::Intern::new(InnerType::Int { signed: true, size: IntSize::Bits(16) }) };
+    typ ::= I32 { internment::Intern::new(InnerType::Int { signed: true, size: IntSize::Bits(32) }) };
+    typ ::= I64 { internment::Intern::new(InnerType::Int { signed: true, size: IntSize::Bits(64) }) };
+    typ ::= U1 { internment::Intern::new(InnerType::Int { signed: false, size: IntSize::Bits(1) }) };
+    typ ::= U8 { internment::Intern::new(InnerType::Int { signed: false, size: IntSize::Bits(8) }) };
+    typ ::= U16 { internment::Intern::new(InnerType::Int { signed: false, size: IntSize::Bits(16) }) };
+    typ ::= U32 { internment::Intern::new(InnerType::Int { signed: false, size: IntSize::Bits(32) }) };
+    typ ::= U64 { internment::Intern::new(InnerType::Int { signed: false, size: IntSize::Bits(64) }) };
+    typ ::= ISize { internment::Intern::new(InnerType::Int { signed: true, size: IntSize::Pointer }) };
+    typ ::= USize { internment::Intern::new(InnerType::Int { signed: false, size: IntSize::Pointer }) };
     typ ::= F32 { internment::Intern::new(InnerType::Float { float_type: FloatType::F32 }) };
     typ ::= F64 { internment::Intern::new(InnerType::Float { float_type: FloatType::F64 }) };
     typ ::= Bang { internment::Intern::new(InnerType::Bottom) };
-    typ ::= LParen RParen { internment::Intern::new(InnerType::Unit) };
+    typ ::= unit { internment::Intern::new(InnerType::Unit) };
+    typ ::= Void { internment::Intern::new(InnerType::Unit) };
+
+    unit ::= LParen RParen;
+
+    %type expr Index;
+    %type stmt Index;
+    %type stmts Vec<Index>;
+    expr ::= { extra.push(AstNode::NoopExpr)};
+    stmt ::= expr(expr) Semi { extra.push(AstNode::Stmt { expr }) };
+
+    stmts ::= stmt(s) { vec![s] };
+    stmts ::= stmts(ss) stmt(s) {
+        let mut v = ss;
+        v.push(s);
+        v
+    };
+    block ::= LBrace stmts?(ss) RBrace {
+        extra.push(AstNode::Block {
+            statements: ss.unwrap_or_default(),
+            expr: None })
+    };
+
+    %type vis Visibility;
+    vis ::= Pub { Visibility::Public };
+
+    %type mutable bool;
+    mutable ::= Mutable { true };
+    mutable ::= { false };
 
     return_type ::= Arrow typ(return_type) { return_type };
-    block ::= LBrace RBrace { extra.push(AstNode::Block { statements: vec![], expr: None }) };
-    parameter ::= Ident(name) Colon typ(param_type) {
-        Parameter { name: name.0.to_string(), param_type }
+    parameter ::= mutable(mutable) Ident(name) Colon typ(param_type) {
+        Parameter { mutable, name: name.to_string(), param_type }
     };
     parameter_list ::= parameter(p) {
         let idx = extra.push(AstNode::Parameter { name: p.name, param_type: p.param_type });
@@ -360,11 +427,12 @@ pomelo! {
         pl
     };
 
-    decl ::= fn_decl(f) { extra.nodes.push(AstNode::FunctionDecl(f)); };
-    fn_decl ::= Fn Ident(name) LParen parameter_list?(parameters) RParen return_type(rtype) block(body) {
-        let name = name.0.to_string();
+    decl ::= fn_decl(f) { extra.push(AstNode::FunctionDecl(f)) };
+    fn_decl ::= vis?(visibility) Fn Ident(name) LParen parameter_list?(parameters) RParen return_type(rtype) block(body) {
+        let name = name.to_string();
         FunctionDecl {
             name,
+            visibility: visibility.unwrap_or_default(),
             return_type: rtype,
             parameter_list: parameters,
             body,
@@ -372,6 +440,109 @@ pomelo! {
     };
 }
 
+impl<'a> From<lexer::Token<'a>> for parser::Token<'a> {
+    fn from(value: lexer::Token<'a>) -> Self {
+        use lexer::Token;
+        match value {
+            Token::Fn => Self::Fn,
+            Token::OpenParens => Self::LParen,
+            Token::CloseParens => Self::RParen,
+            Token::OpenBrace => Self::LBrace,
+            Token::CloseBrace => Self::RBrace,
+            Token::Ident(ident) => Self::Ident(ident),
+            Token::Comment(text) => Self::Comment(text),
+            Token::DocComment(text) => Self::DocComment(text),
+            Token::OpenSquareBracket => todo!(), // Self::LBracket,
+            Token::CloseSquareBracket => todo!(), // Self::RBracket,
+            Token::Comma => Self::Comma,
+            Token::Colon => Self::Colon,
+            Token::Semi => Self::Semi,
+            Token::Elipsis3 => todo!(),
+            Token::Elipsis2 => todo!(),
+            Token::Equal => todo!(),
+            Token::Void => Self::Void,
+            Token::Bool => Self::Bool,
+            Token::F32 => Self::F32,
+            Token::F64 => Self::F64,
+            Token::ISize => Self::ISize,
+            Token::USize => Self::USize,
+            Token::U1 => Self::U1,
+            Token::U8 => Self::U8,
+            Token::U16 => Self::U16,
+            Token::U32 => Self::U32,
+            Token::U64 => Self::U64,
+            Token::I1 => Self::I1,
+            Token::I8 => Self::I8,
+            Token::I16 => Self::I16,
+            Token::I32 => Self::I32,
+            Token::I64 => Self::I64,
+            Token::Const => todo!(), // Self::Const,
+            Token::Mutable => Self::Mutable,
+            Token::Volatile => todo!(),
+            Token::Noalias => todo!(),
+            Token::Let => todo!(),
+            Token::Var => todo!(),
+            Token::If => todo!(),
+            Token::As => todo!(),
+            Token::Else => todo!(),
+            Token::Return => todo!(),
+            Token::Struct => todo!(),
+            Token::Type => todo!(),
+            Token::Union => todo!(),
+            Token::Enum => todo!(),
+            Token::Packed => todo!(),
+            Token::Extern => todo!(),
+            Token::Pub => Self::Pub,
+            Token::Module => todo!(),
+            Token::Dot => todo!(),
+            Token::MinusGreater => Self::Arrow,
+            Token::Bang => Self::Bang,
+            Token::Tilde => todo!(),
+            Token::Plus => todo!(),
+            Token::Minus => todo!(),
+            Token::Star => todo!(),
+            Token::Slash => todo!(),
+            Token::Percent => todo!(),
+            Token::Less => todo!(),
+            Token::Greater => todo!(),
+            Token::LessEqual => todo!(),
+            Token::GreaterEqual => todo!(),
+            Token::EqualEqual => todo!(),
+            Token::BangEqual => todo!(),
+            Token::PipePipe => todo!(),
+            Token::AmpersandAmpersand => todo!(),
+            Token::Ampersand => todo!(),
+            Token::Caret => todo!(),
+            Token::Pipe => todo!(),
+            Token::LessLess => todo!(),
+            Token::GreaterGreater => todo!(),
+            Token::Question => todo!(),
+            Token::PlusEqual => todo!(),
+            Token::MinusEqual => todo!(),
+            Token::StarEqual => todo!(),
+            Token::SlashEqual => todo!(),
+            Token::PercentEqual => todo!(),
+            Token::AmpersandEqual => todo!(),
+            Token::PipeEqual => todo!(),
+            Token::CaretEqual => todo!(),
+            Token::LessLessEqual => todo!(),
+            Token::GreaterGreaterEqual => todo!(),
+            Token::Eof(_) => todo!(),
+            Token::ParseError(_) => todo!(),
+            Token::CharConstant(_) => todo!(),
+            Token::IntegerConstant(_) => todo!(),
+            Token::IntegerHexConstant(_) => todo!(),
+            Token::IntegerBinConstant(_) => todo!(),
+            Token::IntegerOctConstant(_) => todo!(),
+            Token::FloatingConstant(_) => todo!(),
+            Token::FloatingExpConstant(_) => todo!(),
+            Token::DotFloatingConstant(_) => todo!(),
+            Token::DotFloatingExpConstant(_) => todo!(),
+            Token::StringConstant(_) => todo!(),
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::AstNode;
@@ -380,4 +551,19 @@ mod tests {
     fn print_ast_node_size() {
         eprintln!("Size of AstNode: {}", std::mem::size_of::<AstNode>());
     }
+
+    #[test]
+    fn parse() {
+        use crate::parser::{Parser, Token};
+        let input = "fn main(a: u32, b: u32) -> u32 {}";
+        let mut lex = lexer::TokenIterator::new(input);
+        let mut mapped = lex.inspect(|t| eprintln!("{t:?}")).map(Token::from);
+        let mut ast = crate::Ast::new();
+        let mut parser = Parser::new(ast);
+        while let Some(token) = mapped.next() {
+            parser.parse(token).unwrap();
+        }
+        let (out, ast) = parser.end_of_input().unwrap();
+        eprintln!("AST: {:#?}", ast);
+    }
 }