diff --git a/src/ast2/intern.rs b/src/ast2/intern.rs
index 59fc884..6f38e6d 100644
--- a/src/ast2/intern.rs
+++ b/src/ast2/intern.rs
@@ -39,6 +39,23 @@ impl From<u8> for SimpleType {
     }
 }
 
+impl Display for SimpleType {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            match self {
+                SimpleType::F32 => "f32",
+                SimpleType::F64 => "f64",
+                SimpleType::Bool => "bool",
+                SimpleType::Void => "void",
+                SimpleType::USize => "usize",
+                SimpleType::ISize => "isize",
+                SimpleType::ComptimeInt => "comptime_int",
+            }
+        )
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum Tag {
     String,
@@ -134,6 +151,86 @@ pub enum Key<'a> {
     FalseValue,
 }
 
+struct KeyDisplay<'a> {
+    ip: &'a InternPool,
+    key: Key<'a>,
+}
+
+struct DisplayCommaSep<T: IntoIterator<Item = Display>> {
+    t: T,
+}
+
+impl<T: IntoIterator<Item = Display>> Display for DisplayCommaSep<T> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut iter = self.t.into_iter();
+
+        let Some(ref next) = iter.next() else {
+            return Ok(());
+        };
+        write!(f, "{next}")?;
+
+        for ref item in iter {
+            write!(f, ", {next}")?;
+        }
+
+        Ok(())
+    }
+}
+
+impl Display for KeyDisplay<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self.key {
+            Key::String { str } => write!(f, "\"{str}\"")?,
+            Key::Bytes { bytes } => write!(f, "{bytes:>02x?}")?,
+            Key::SIntSmall { bits } => write!(f, "{bits}")?,
+            Key::UIntSmall { bits } => write!(f, "{bits}")?,
+            Key::SInt64 { bits } => write!(f, "{bits}")?,
+            Key::UInt64 { bits } => write!(f, "{bits}")?,
+            Key::F32 { bits } => write!(f, "{bits}")?,
+            Key::F64 { bits } => write!(f, "{bits}")?,
+            Key::PositiveInt { bigint } => write!(f, "{bigint}")?,
+            Key::NegativeInt { bigint } => write!(f, "{bigint}")?,
+            Key::UIntType { bit_width } => write!(f, "u{bit_width}")?,
+            Key::SIntType { bit_width } => write!(f, "i{bit_width}")?,
+            Key::SimpleType { ty } => write!(f, "{ty}")?,
+            Key::PointerType { pointee, flags } => {
+                write!(f, "*{flags}{}", self.ip.display_key(pointee))?
+            }
+            Key::ArrayType {
+                pointee,
+                flags,
+                length,
+            } => write!(
+                f,
+                "[{flags}{}; {length}]",
+                self.ip.display_key(pointee)
+            )?,
+            Key::FunctionType {
+                return_type,
+                parameters,
+            } => write!(
+                f,
+                "fn ({}) -> {}",
+                DisplayCommaSep {
+                    t: parameters.iter().map(|&ty| self.ip.display_key(ty))
+                },
+                self.ip.display_key(return_type)
+            )?,
+            Key::StructType {
+                decl,
+                name,
+                packed,
+                c_like,
+                fields,
+            } => todo!(),
+            Key::TrueValue => write!(f, "true"),
+            Key::FalseValue => write!(f, "false"),
+        }
+
+        Ok(())
+    }
+}
+
 impl Hash for Key<'_> {
     fn hash<H: Hasher>(&self, state: &mut H) {
         core::mem::discriminant(self).hash(state);
@@ -175,6 +272,22 @@ pub struct PointerFlags {
     pub noalias: bool,
 }
 
+impl Display for PointerFlags {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if self.is_const {
+            write!(f, "const ")?
+        }
+        if self.volatile {
+            write!(f, "volatile ")?
+        }
+        if self.noalias {
+            write!(f, "noalias ")?
+        }
+
+        Ok(())
+    }
+}
+
 impl PointerFlags {
     pub fn new(is_const: bool, volatile: bool, noalias: bool) -> Self {
         Self {
@@ -343,6 +456,15 @@ impl std::fmt::Debug for InternPool {
     }
 }
 
+impl InternPool {
+    pub fn display_key(&self, index: Index) -> KeyDisplay<'_> {
+        KeyDisplay {
+            ip: self,
+            key: self.get_key(index),
+        }
+    }
+}
+
 macro_rules! static_keys {
     ($($name:ident => $def:expr),* $(,)?) => {
         impl Index {
@@ -891,7 +1013,8 @@ impl InternPool {
             }
             Key::PointerType { pointee, flags } => {
                 let flags = flags.pack();
-                let i = self.extend_words([pointee.index(), flags as u32]);
+                let i =
+                    self.extend_words([pointee.index() as u32, flags as u32]);
                 self.create_item(Tag::PointerType, i)
             }
             Key::ArrayType {
@@ -900,8 +1023,11 @@ impl InternPool {
                 length,
             } => {
                 let flags = flags.pack();
-                let i =
-                    self.extend_words([pointee.index(), flags as u32, length]);
+                let i = self.extend_words([
+                    pointee.index() as u32,
+                    flags as u32,
+                    length,
+                ]);
                 self.create_item(Tag::ArrayType, i)
             }
             Key::StructType {
@@ -942,8 +1068,9 @@ impl InternPool {
 
                 let start = self.push_word(info.pack());
                 self.extend_words([return_type.into_u32()]);
-                _ = self
-                    .extend_words(parameters.into_iter().map(|i| i.index()));
+                _ = self.extend_words(
+                    parameters.into_iter().map(|i| i.index() as u32),
+                );
 
                 self.create_item(Tag::FunctionType, start)
             }