diff --git a/src/ty/internal/attrset.rs b/src/ty/internal/attrset.rs
index beacfb6..e491250 100644
--- a/src/ty/internal/attrset.rs
+++ b/src/ty/internal/attrset.rs
@@ -45,7 +45,18 @@ impl<'vm> AttrSet<'vm> {
         self.data = self
             .data
             .into_iter()
-            .map(|(k, v)| (k.clone(), match v.clone() { x @ Value::ThunkRef(thunk) => { thunk.capture(env.clone()); x }, x => x }))
+            .map(|(k, v)| {
+                (
+                    k.clone(),
+                    match v.clone() {
+                        x @ Value::ThunkRef(thunk) => {
+                            thunk.capture(env.clone());
+                            x
+                        }
+                        x => x,
+                    },
+                )
+            })
             .collect();
     }
 
@@ -99,7 +110,7 @@ impl ToPublic for AttrSet<'_> {
 
 #[derive(Debug, Constructor, Clone, PartialEq)]
 pub struct RecAttrSet<'vm> {
-    data: Rc<Env<'vm>>
+    data: Rc<Env<'vm>>,
 }
 
 impl<'vm> RecAttrSet<'vm> {
@@ -178,7 +189,8 @@ impl<'vm> RecAttrSet<'vm> {
 impl ToPublic for RecAttrSet<'_> {
     fn to_public(self, vm: &VM) -> p::Value {
         p::Value::AttrSet(p::AttrSet::new(
-            self.data.map
+            self.data
+                .map
                 .borrow()
                 .iter()
                 .map(|(sym, value)| (sym.clone(), value.clone().to_public(vm)))
diff --git a/src/ty/internal/mod.rs b/src/ty/internal/mod.rs
index 8bb79bf..6046921 100644
--- a/src/ty/internal/mod.rs
+++ b/src/ty/internal/mod.rs
@@ -25,77 +25,6 @@ pub use func::*;
 pub use list::List;
 pub use primop::*;
 
-pub trait ToPublic {
-    fn to_public(self, vm: &VM) -> p::Value;
-}
-
-#[derive(Debug, Clone)]
-pub struct Thunk<'vm> {
-    pub thunk: RefCell<_Thunk<'vm>>,
-    pub env: RefCell<Option<Rc<Env<'vm>>>>,
-}
-
-#[derive(Debug, IsVariant, Unwrap, Clone)]
-pub enum _Thunk<'vm> {
-    Code(OpCodes),
-    SuspendedFrom(*const Thunk<'vm>),
-    Value(Box<Value<'vm>>),
-}
-
-impl<'vm> Thunk<'vm> {
-    pub fn new(opcodes: OpCodes) -> Self {
-        Thunk {
-            thunk: RefCell::new(_Thunk::Code(opcodes)),
-            env: RefCell::new(None),
-        }
-    }
-
-    pub fn unwrap_code(&self) -> OpCodes {
-        self.thunk.borrow().clone().unwrap_code()
-    }
-
-    pub fn capture(&self, env: Rc<Env<'vm>>) {
-        *self.env.borrow_mut() = Some(env);
-    }
-
-    pub fn force(&self, vm: &VM<'vm>) -> Result<Value<'vm>> {
-        match &*self.thunk.borrow() {
-            _Thunk::Value(value) => return Ok(value.as_ref().clone()),
-            _Thunk::SuspendedFrom(from) => {
-                return Err(Error::EvalError(format!(
-                    "thunk {:p} already suspended from {from:p} (infinite recursion encountered)",
-                    self as *const Thunk
-                )));
-            }
-            _Thunk::Code(_) => (),
-        }
-        let opcodes = std::mem::replace(
-            &mut *self.thunk.borrow_mut(),
-            _Thunk::SuspendedFrom(self as *const Thunk),
-        )
-        .unwrap_code();
-        let value = vm.eval(opcodes, self.env.borrow().clone().unwrap())?;
-        let _ = std::mem::replace(
-            &mut *self.thunk.borrow_mut(),
-            _Thunk::Value(value.clone().into()),
-        );
-        Ok(value)
-    }
-
-    pub fn value(&'vm self) -> Option<Value<'vm>> {
-        match &*self.thunk.borrow() {
-            _Thunk::Value(value) => Some(value.as_ref().clone()),
-            _ => None,
-        }
-    }
-}
-
-impl PartialEq for Thunk<'_> {
-    fn eq(&self, _: &Self) -> bool {
-        false
-    }
-}
-
 #[derive(Debug, IsVariant, Unwrap, Clone, PartialEq)]
 pub enum Value<'vm> {
     Const(Const),
@@ -484,3 +413,74 @@ impl ToPublic for Value<'_> {
         }
     }
 }
+
+pub trait ToPublic {
+    fn to_public(self, vm: &VM) -> p::Value;
+}
+
+#[derive(Debug, Clone)]
+pub struct Thunk<'vm> {
+    pub thunk: RefCell<_Thunk<'vm>>,
+    pub env: RefCell<Option<Rc<Env<'vm>>>>,
+}
+
+#[derive(Debug, IsVariant, Unwrap, Clone)]
+pub enum _Thunk<'vm> {
+    Code(OpCodes),
+    SuspendedFrom(*const Thunk<'vm>),
+    Value(Box<Value<'vm>>),
+}
+
+impl<'vm> Thunk<'vm> {
+    pub fn new(opcodes: OpCodes) -> Self {
+        Thunk {
+            thunk: RefCell::new(_Thunk::Code(opcodes)),
+            env: RefCell::new(None),
+        }
+    }
+
+    pub fn unwrap_code(&self) -> OpCodes {
+        self.thunk.borrow().clone().unwrap_code()
+    }
+
+    pub fn capture(&self, env: Rc<Env<'vm>>) {
+        *self.env.borrow_mut() = Some(env);
+    }
+
+    pub fn force(&self, vm: &VM<'vm>) -> Result<Value<'vm>> {
+        match &*self.thunk.borrow() {
+            _Thunk::Value(value) => return Ok(value.as_ref().clone()),
+            _Thunk::SuspendedFrom(from) => {
+                return Err(Error::EvalError(format!(
+                    "thunk {:p} already suspended from {from:p} (infinite recursion encountered)",
+                    self as *const Thunk
+                )));
+            }
+            _Thunk::Code(_) => (),
+        }
+        let opcodes = std::mem::replace(
+            &mut *self.thunk.borrow_mut(),
+            _Thunk::SuspendedFrom(self as *const Thunk),
+        )
+        .unwrap_code();
+        let value = vm.eval(opcodes, self.env.borrow().clone().unwrap())?;
+        let _ = std::mem::replace(
+            &mut *self.thunk.borrow_mut(),
+            _Thunk::Value(value.clone().into()),
+        );
+        Ok(value)
+    }
+
+    pub fn value(&'vm self) -> Option<Value<'vm>> {
+        match &*self.thunk.borrow() {
+            _Thunk::Value(value) => Some(value.as_ref().clone()),
+            _ => None,
+        }
+    }
+}
+
+impl PartialEq for Thunk<'_> {
+    fn eq(&self, _: &Self) -> bool {
+        false
+    }
+}
diff --git a/src/vm/mod.rs b/src/vm/mod.rs
index bb0be16..b029b22 100644
--- a/src/vm/mod.rs
+++ b/src/vm/mod.rs
@@ -86,8 +86,7 @@ impl<'vm> VM<'vm> {
         opcode: OpCode,
         stack: &'s mut Stack<'vm, CAP>,
         env: &Rc<Env<'vm>>,
-    ) -> Result<usize>
-    {
+    ) -> Result<usize> {
         match opcode {
             OpCode::Illegal => panic!("illegal opcode"),
             OpCode::Const { value } => stack.push(Value::Const(value))?,
@@ -170,8 +169,12 @@ impl<'vm> VM<'vm> {
             }
             OpCode::FinalizeRec => {
                 env.enter(stack.tos()?.clone().unwrap_attr_set().into_inner());
-                stack.tos_mut()?.as_mut().unwrap_attr_set().capture(env.clone());
-            },
+                stack
+                    .tos_mut()?
+                    .as_mut()
+                    .unwrap_attr_set()
+                    .capture(env.clone());
+            }
             OpCode::PushStaticAttr { name } => {
                 let val = stack.pop();
                 stack.tos_mut()?.push_attr(Symbol::new(name.clone()), val);