#![allow(non_snake_case)]
use std::borrow::Borrow;
use std::borrow::Cow;
use std::collections::BTreeMap;
use std::fmt;

use crate::expr::*;
use crate::normalize::{NormalizationContext, Thunk, TypeThunk, Value};
use crate::traits::DynamicType;
use dhall_proc_macros as dhall;
use dhall_syntax;
use dhall_syntax::context::Context;
use dhall_syntax::*;

use self::TypeMessage::*;

type InputSubExpr = SubExpr<Label, Span, Normalized>;
type OutputSubExpr = SubExpr<Label, X, X>;

impl Resolved {
    pub fn typecheck(self) -> Result<Typed, TypeError> {
        type_of(self.0)
    }
    pub fn typecheck_with(self, ty: &Type) -> Result<Typed, TypeError> {
        let expr = self.0;
        let ty = ty.to_expr().embed_absurd().note_absurd();
        type_of(expr.rewrap(ExprF::Annot(expr.clone(), ty)))
    }
    /// Pretends this expression has been typechecked. Use with care.
    #[allow(dead_code)]
    pub fn skip_typecheck(self) -> Typed {
        Typed::from_thunk_untyped(Thunk::new(
            NormalizationContext::new(),
            self.0,
        ))
    }
}

impl Typed {
    fn to_type(&self) -> Type {
        match &self.to_value() {
            Value::Const(c) => Type(TypeInternal::Const(*c)),
            _ => Type(TypeInternal::Typed(Box::new(self.clone()))),
        }
    }
}

impl Normalized {
    fn shift(&self, delta: isize, var: &Var<Label>) -> Self {
        Normalized(self.0.shift(delta, var))
    }
    pub(crate) fn to_type(self) -> Type {
        self.0.to_type()
    }
}

impl Type {
    pub(crate) fn to_normalized(&self) -> Normalized {
        self.0.to_normalized()
    }
    pub(crate) fn to_expr(&self) -> OutputSubExpr {
        self.0.to_expr()
    }
    pub(crate) fn to_value(&self) -> Value {
        self.0.to_value()
    }
    pub(crate) fn get_type(&self) -> Result<Cow<'_, Type>, TypeError> {
        self.0.get_type()
    }
    fn as_const(&self) -> Option<Const> {
        self.0.as_const()
    }
    fn internal(&self) -> &TypeInternal {
        &self.0
    }
    fn internal_whnf(&self) -> Option<Value> {
        self.0.whnf()
    }
    pub(crate) fn shift(&self, delta: isize, var: &Var<Label>) -> Self {
        Type(self.0.shift(delta, var))
    }
    pub(crate) fn subst_shift(&self, var: &Var<Label>, val: &Typed) -> Self {
        Type(self.0.subst_shift(var, val))
    }

    fn const_sort() -> Self {
        Type(TypeInternal::Const(Const::Sort))
    }
    fn const_kind() -> Self {
        Type(TypeInternal::Const(Const::Kind))
    }
    pub(crate) fn const_type() -> Self {
        Type(TypeInternal::Const(Const::Type))
    }
}

impl TypeThunk {
    fn to_type(&self, ctx: &TypecheckContext) -> Result<Type, TypeError> {
        match self {
            TypeThunk::Type(t) => Ok(t.clone()),
            TypeThunk::Thunk(th) => {
                // TODO: rule out statically
                mktype(ctx, th.normalize_to_expr().embed_absurd().note_absurd())
            }
        }
    }
}

/// A semantic type. This is partially redundant with `dhall_syntax::Expr`, on purpose. `TypeInternal` should
/// be limited to syntactic expressions: either written by the user or meant to be printed.
/// The rule is the following: we must _not_ construct values of type `Expr` while typechecking,
/// but only construct `TypeInternal`s.
#[derive(Debug, Clone)]
pub(crate) enum TypeInternal {
    Const(Const),
    /// This must not contain a Const value.
    Typed(Box<Typed>),
}

impl TypeInternal {
    fn to_typed(&self) -> Typed {
        match self {
            TypeInternal::Typed(e) => e.as_ref().clone(),
            TypeInternal::Const(c) => const_to_typed(*c),
        }
    }
    fn to_normalized(&self) -> Normalized {
        self.to_typed().normalize()
    }
    fn to_expr(&self) -> OutputSubExpr {
        self.to_normalized().to_expr()
    }
    fn to_value(&self) -> Value {
        self.to_typed().to_value()
    }
    pub(crate) fn get_type(&self) -> Result<Cow<'_, Type>, TypeError> {
        Ok(match self {
            TypeInternal::Typed(e) => e.get_type()?,
            TypeInternal::Const(c) => Cow::Owned(type_of_const(*c)?),
        })
    }
    fn as_const(&self) -> Option<Const> {
        match self {
            TypeInternal::Const(c) => Some(*c),
            _ => None,
        }
    }
    fn whnf(&self) -> Option<Value> {
        match self {
            TypeInternal::Typed(e) => Some(e.to_value()),
            _ => None,
        }
    }
    fn shift(&self, delta: isize, var: &Var<Label>) -> Self {
        use TypeInternal::*;
        match self {
            Typed(e) => Typed(Box::new(e.shift(delta, var))),
            Const(c) => Const(*c),
        }
    }
    fn subst_shift(&self, var: &Var<Label>, val: &Typed) -> Self {
        use TypeInternal::*;
        match self {
            Typed(e) => Typed(Box::new(e.subst_shift(var, val))),
            Const(c) => Const(*c),
        }
    }
}

impl Eq for TypeInternal {}
impl PartialEq for TypeInternal {
    fn eq(&self, other: &Self) -> bool {
        self.to_normalized() == other.to_normalized()
    }
}

#[derive(Debug, Clone)]
pub(crate) enum EnvItem {
    Type(Var<Label>, Type),
    Value(Normalized),
}

impl EnvItem {
    fn shift(&self, delta: isize, var: &Var<Label>) -> Self {
        use EnvItem::*;
        match self {
            Type(v, e) => Type(v.shift(delta, var), e.shift(delta, var)),
            Value(e) => Value(e.shift(delta, var)),
        }
    }
}

#[derive(Debug, Clone)]
pub(crate) struct TypecheckContext(pub(crate) Context<Label, EnvItem>);

impl TypecheckContext {
    pub(crate) fn new() -> Self {
        TypecheckContext(Context::new())
    }
    pub(crate) fn insert_type(&self, x: &Label, t: Type) -> Self {
        TypecheckContext(
            self.0.map(|_, e| e.shift(1, &x.into())).insert(
                x.clone(),
                EnvItem::Type(x.into(), t.shift(1, &x.into())),
            ),
        )
    }
    pub(crate) fn insert_value(&self, x: &Label, t: Normalized) -> Self {
        TypecheckContext(self.0.insert(x.clone(), EnvItem::Value(t)))
    }
    pub(crate) fn lookup(&self, var: &Var<Label>) -> Option<Cow<'_, Type>> {
        let Var(x, n) = var;
        match self.0.lookup(x, *n) {
            Some(EnvItem::Type(_, t)) => Some(Cow::Borrowed(&t)),
            Some(EnvItem::Value(t)) => Some(t.get_type()?),
            None => None,
        }
    }
    fn to_normalization_ctx(&self) -> NormalizationContext {
        NormalizationContext::from_typecheck_ctx(self)
    }
}

impl PartialEq for TypecheckContext {
    fn eq(&self, _: &Self) -> bool {
        // don't count contexts when comparing stuff
        // this is dirty but needed for now
        true
    }
}
impl Eq for TypecheckContext {}

fn function_check(a: Const, b: Const) -> Result<Const, ()> {
    use dhall_syntax::Const::*;
    match (a, b) {
        (_, Type) => Ok(Type),
        (Kind, Kind) => Ok(Kind),
        (Sort, Sort) => Ok(Sort),
        (Sort, Kind) => Ok(Sort),
        _ => Err(()),
    }
}

fn match_vars(
    vl: &Var<Label>,
    vr: &Var<Label>,
    ctx: &[(&Label, &Label)],
) -> bool {
    let (Var(xL, mut nL), Var(xR, mut nR)) = (vl, vr);
    for &(xL2, xR2) in ctx {
        match (nL, nR) {
            (0, 0) if xL == xL2 && xR == xR2 => return true,
            (_, _) => {
                if xL == xL2 {
                    nL -= 1;
                }
                if xR == xR2 {
                    nR -= 1;
                }
            }
        }
    }
    xL == xR && nL == nR
}

// Equality up to alpha-equivalence (renaming of bound variables)
fn prop_equal<T, U>(eL0: T, eR0: U) -> bool
where
    T: Borrow<Type>,
    U: Borrow<Type>,
{
    use dhall_syntax::ExprF::*;
    fn go<'a, S, T>(
        ctx: &mut Vec<(&'a Label, &'a Label)>,
        el: &'a SubExpr<Label, S, X>,
        er: &'a SubExpr<Label, T, X>,
    ) -> bool
    where
        S: ::std::fmt::Debug,
        T: ::std::fmt::Debug,
    {
        match (el.as_ref(), er.as_ref()) {
            (Const(a), Const(b)) => a == b,
            (Builtin(a), Builtin(b)) => a == b,
            (Var(vL), Var(vR)) => match_vars(vL, vR, ctx),
            (Pi(xL, tL, bL), Pi(xR, tR, bR)) => {
                go(ctx, tL, tR) && {
                    ctx.push((xL, xR));
                    let eq2 = go(ctx, bL, bR);
                    ctx.pop();
                    eq2
                }
            }
            (App(fL, aL), App(fR, aR)) => go(ctx, fL, fR) && go(ctx, aL, aR),
            (RecordType(ktsL0), RecordType(ktsR0)) => {
                ktsL0.len() == ktsR0.len()
                    && ktsL0
                        .iter()
                        .zip(ktsR0.iter())
                        .all(|((kL, tL), (kR, tR))| kL == kR && go(ctx, tL, tR))
            }
            (UnionType(ktsL0), UnionType(ktsR0)) => {
                ktsL0.len() == ktsR0.len()
                    && ktsL0.iter().zip(ktsR0.iter()).all(
                        |((kL, tL), (kR, tR))| {
                            kL == kR
                                && match (tL, tR) {
                                    (None, None) => true,
                                    (Some(tL), Some(tR)) => go(ctx, tL, tR),
                                    _ => false,
                                }
                        },
                    )
            }
            (_, _) => false,
        }
    }
    match (eL0.borrow().internal(), eR0.borrow().internal()) {
        // (TypeInternal::Const(cl), TypeInternal::Const(cr)) => cl == cr,
        // (TypeInternal::Expr(l), TypeInternal::Expr(r)) => {
        _ => {
            let mut ctx = vec![];
            go(
                &mut ctx,
                &eL0.borrow().to_expr(),
                &eR0.borrow().to_expr(),
            )
        }
        // _ => false,
    }
}

fn const_to_typed(c: Const) -> Typed {
    match c {
        Const::Sort => Typed::const_sort(),
        _ => Typed::from_thunk_and_type(
            Value::Const(c).into_thunk(),
            type_of_const(c).unwrap(),
        ),
    }
}

fn const_to_type(c: Const) -> Type {
    Type(TypeInternal::Const(c))
}

fn type_of_const(c: Const) -> Result<Type, TypeError> {
    match c {
        Const::Type => Ok(Type::const_kind()),
        Const::Kind => Ok(Type::const_sort()),
        Const::Sort => {
            return Err(TypeError::new(
                &TypecheckContext::new(),
                TypeMessage::Sort,
            ))
        }
    }
}

fn type_of_builtin(b: Builtin) -> InputSubExpr {
    use dhall_syntax::Builtin::*;
    rc(match b {
        Bool | Natural | Integer | Double | Text => dhall::expr!(Type),
        List | Optional => dhall::expr!(
            Type -> Type
        ),

        NaturalFold => dhall::expr!(
            Natural ->
            forall (natural: Type) ->
            forall (succ: natural -> natural) ->
            forall (zero: natural) ->
            natural
        ),
        NaturalBuild => dhall::expr!(
            (forall (natural: Type) ->
                forall (succ: natural -> natural) ->
                forall (zero: natural) ->
                natural) ->
            Natural
        ),
        NaturalIsZero | NaturalEven | NaturalOdd => dhall::expr!(
            Natural -> Bool
        ),
        NaturalToInteger => dhall::expr!(Natural -> Integer),
        NaturalShow => dhall::expr!(Natural -> Text),

        IntegerToDouble => dhall::expr!(Integer -> Double),
        IntegerShow => dhall::expr!(Integer -> Text),
        DoubleShow => dhall::expr!(Double -> Text),
        TextShow => dhall::expr!(Text -> Text),

        ListBuild => dhall::expr!(
            forall (a: Type) ->
            (forall (list: Type) ->
                forall (cons: a -> list -> list) ->
                forall (nil: list) ->
                list) ->
            List a
        ),
        ListFold => dhall::expr!(
            forall (a: Type) ->
            List a ->
            forall (list: Type) ->
            forall (cons: a -> list -> list) ->
            forall (nil: list) ->
            list
        ),
        ListLength => dhall::expr!(forall (a: Type) -> List a -> Natural),
        ListHead | ListLast => {
            dhall::expr!(forall (a: Type) -> List a -> Optional a)
        }
        ListIndexed => dhall::expr!(
            forall (a: Type) ->
            List a ->
            List { index: Natural, value: a }
        ),
        ListReverse => dhall::expr!(
            forall (a: Type) -> List a -> List a
        ),

        OptionalBuild => dhall::expr!(
            forall (a: Type) ->
            (forall (optional: Type) ->
                forall (just: a -> optional) ->
                forall (nothing: optional) ->
                optional) ->
            Optional a
        ),
        OptionalFold => dhall::expr!(
            forall (a: Type) ->
            Optional a ->
            forall (optional: Type) ->
            forall (just: a -> optional) ->
            forall (nothing: optional) ->
            optional
        ),
        // TODO: alpha-equivalence in type-inference tests
        OptionalNone => dhall::expr!(
            forall (A: Type) -> Optional A
        ),
    })
    .note_absurd()
}

macro_rules! ensure_equal {
    ($x:expr, $y:expr, $err:expr $(,)*) => {
        if !prop_equal($x, $y) {
            return Err($err);
        }
    };
}

// Ensure the provided type has type `Type`
macro_rules! ensure_simple_type {
    ($x:expr, $err:expr $(,)*) => {{
        match $x.get_type()?.as_const() {
            Some(dhall_syntax::Const::Type) => {}
            _ => return Err($err),
        }
    }};
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub(crate) enum TypeIntermediate {
    Pi(TypecheckContext, Label, Type, Type),
    RecordType(TypecheckContext, BTreeMap<Label, Type>),
    UnionType(TypecheckContext, BTreeMap<Label, Option<Type>>),
    ListType(TypecheckContext, Type),
    OptionalType(TypecheckContext, Type),
}

impl TypeIntermediate {
    fn typecheck(self) -> Result<Typed, TypeError> {
        let mkerr = |ctx, msg| TypeError::new(ctx, msg);
        Ok(match &self {
            TypeIntermediate::Pi(ctx, x, ta, tb) => {
                let ctx2 = ctx.insert_type(x, ta.clone());

                let kA = match ta.get_type()?.as_const() {
                    Some(k) => k,
                    _ => {
                        return Err(mkerr(
                            ctx,
                            InvalidInputType(ta.clone().to_normalized()),
                        ))
                    }
                };

                let kB = match tb.get_type()?.as_const() {
                    Some(k) => k,
                    _ => {
                        return Err(mkerr(
                            &ctx2,
                            InvalidOutputType(
                                tb.clone()
                                    .to_normalized()
                                    .get_type()?
                                    .to_normalized(),
                            ),
                        ))
                    }
                };

                let k = match function_check(kA, kB) {
                    Ok(k) => k,
                    Err(()) => {
                        return Err(mkerr(
                            ctx,
                            NoDependentTypes(
                                ta.clone().to_normalized(),
                                tb.clone()
                                    .to_normalized()
                                    .get_type()?
                                    .to_normalized(),
                            ),
                        ))
                    }
                };

                Typed::from_thunk_and_type(
                    Value::Pi(
                        x.clone(),
                        TypeThunk::from_type(ta.clone()),
                        TypeThunk::from_type(tb.clone()),
                    )
                    .into_thunk(),
                    const_to_type(k),
                )
            }
            TypeIntermediate::RecordType(ctx, kts) => {
                // Check that all types are the same const
                let mut k = None;
                for (x, t) in kts {
                    match (k, t.get_type()?.as_const()) {
                        (None, Some(k2)) => k = Some(k2),
                        (Some(k1), Some(k2)) if k1 == k2 => {}
                        _ => {
                            return Err(mkerr(
                                ctx,
                                InvalidFieldType(x.clone(), t.clone()),
                            ))
                        }
                    }
                }
                // An empty record type has type Type
                let k = k.unwrap_or(dhall_syntax::Const::Type);

                Typed::from_thunk_and_type(
                    Value::RecordType(
                        kts.iter()
                            .map(|(k, t)| {
                                (k.clone(), TypeThunk::from_type(t.clone()))
                            })
                            .collect(),
                    )
                    .into_thunk(),
                    const_to_type(k),
                )
            }
            TypeIntermediate::UnionType(ctx, kts) => {
                // Check that all types are the same const
                let mut k = None;
                for (x, t) in kts {
                    if let Some(t) = t {
                        match (k, t.get_type()?.as_const()) {
                            (None, Some(k2)) => k = Some(k2),
                            (Some(k1), Some(k2)) if k1 == k2 => {}
                            _ => {
                                return Err(mkerr(
                                    ctx,
                                    InvalidFieldType(x.clone(), t.clone()),
                                ))
                            }
                        }
                    }
                }

                // An empty union type has type Type;
                // an union type with only unary variants also has type Type
                let k = k.unwrap_or(dhall_syntax::Const::Type);

                Typed::from_thunk_and_type(
                    Value::UnionType(
                        kts.iter()
                            .map(|(k, t)| {
                                (
                                    k.clone(),
                                    t.as_ref().map(|t| {
                                        TypeThunk::from_type(t.clone())
                                    }),
                                )
                            })
                            .collect(),
                    )
                    .into_thunk(),
                    const_to_type(k),
                )
            }
            TypeIntermediate::ListType(ctx, t) => {
                ensure_simple_type!(
                    t,
                    mkerr(ctx, InvalidListType(t.clone().to_normalized())),
                );
                Typed::from_thunk_and_type(
                    Value::from_builtin(Builtin::List)
                        .app(t.to_value())
                        .into_thunk(),
                    const_to_type(Const::Type),
                )
            }
            TypeIntermediate::OptionalType(ctx, t) => {
                ensure_simple_type!(
                    t,
                    mkerr(ctx, InvalidOptionalType(t.clone().to_normalized())),
                );
                Typed::from_thunk_and_type(
                    Value::from_builtin(Builtin::Optional)
                        .app(t.to_value())
                        .into_thunk(),
                    const_to_type(Const::Type),
                )
            }
        })
    }
}

/// Takes an expression that is meant to contain a Type
/// and turn it into a type, typechecking it along the way.
fn mktype(ctx: &TypecheckContext, e: InputSubExpr) -> Result<Type, TypeError> {
    Ok(type_with(ctx, e)?.to_type())
}

fn builtin_to_type(b: Builtin) -> Result<Type, TypeError> {
    mktype(
        &TypecheckContext::new(),
        SubExpr::from_expr_no_note(ExprF::Builtin(b)),
    )
}

/// Intermediary return type
enum Ret {
    /// Returns the contained value as is
    RetTyped(Typed),
    /// Use the contained Type as the type of the input expression
    RetType(Type),
}

/// Type-check an expression and return the expression alongside its type if type-checking
/// succeeded, or an error if type-checking failed
fn type_with(
    ctx: &TypecheckContext,
    e: InputSubExpr,
) -> Result<Typed, TypeError> {
    use dhall_syntax::ExprF::{
        Annot, App, Embed, Lam, Let, OldOptionalLit, Pi, SomeLit,
    };

    use Ret::*;
    let ret = match e.as_ref() {
        Lam(x, t, b) => {
            let tx = mktype(ctx, t.clone())?;
            let ctx2 = ctx.insert_type(x, tx.clone());
            let b = type_with(&ctx2, b.clone())?;
            let tb = b.get_type()?.into_owned();
            Ok(RetType(
                TypeIntermediate::Pi(ctx.clone(), x.clone(), tx, tb)
                    .typecheck()?
                    .to_type(),
            ))
        }
        Pi(x, ta, tb) => {
            let ta = mktype(ctx, ta.clone())?;
            let ctx2 = ctx.insert_type(x, ta.clone());
            let tb = mktype(&ctx2, tb.clone())?;
            Ok(RetTyped(
                TypeIntermediate::Pi(ctx.clone(), x.clone(), ta, tb)
                    .typecheck()?,
            ))
        }
        Let(x, t, v, e) => {
            let v = if let Some(t) = t {
                t.rewrap(Annot(v.clone(), t.clone()))
            } else {
                v.clone()
            };

            let v = type_with(ctx, v)?.normalize();
            let e = type_with(&ctx.insert_value(x, v.clone()), e.clone())?;

            Ok(RetType(e.get_type()?.into_owned()))
        }
        OldOptionalLit(None, t) => {
            let none = SubExpr::from_expr_no_note(ExprF::Builtin(
                Builtin::OptionalNone,
            ));
            let e = e.rewrap(App(none, t.clone()));
            return type_with(ctx, e);
        }
        OldOptionalLit(Some(x), t) => {
            let optional =
                SubExpr::from_expr_no_note(ExprF::Builtin(Builtin::Optional));
            let x = x.rewrap(SomeLit(x.clone()));
            let t = t.rewrap(App(optional, t.clone()));
            let e = e.rewrap(Annot(x, t));
            return type_with(ctx, e);
        }
        Embed(p) => Ok(RetTyped(p.clone().into())),
        _ => type_last_layer(
            ctx,
            // Typecheck recursively all subexpressions
            e.as_ref()
                .traverse_ref_simple(|e| Ok(type_with(ctx, e.clone())?))?,
        ),
    }?;
    Ok(match ret {
        RetType(typ) => Typed::from_thunk_and_type(
            Thunk::new(ctx.to_normalization_ctx(), e),
            typ,
        ),
        RetTyped(tt) => tt,
    })
}

/// When all sub-expressions have been typed, check the remaining toplevel
/// layer.
fn type_last_layer(
    ctx: &TypecheckContext,
    e: ExprF<Typed, Label, Normalized>,
) -> Result<Ret, TypeError> {
    use dhall_syntax::BinOp::*;
    use dhall_syntax::Builtin::*;
    use dhall_syntax::ExprF::*;
    let mkerr = |msg: TypeMessage| TypeError::new(ctx, msg);

    use Ret::*;
    match e {
        Lam(_, _, _) => unreachable!(),
        Pi(_, _, _) => unreachable!(),
        Let(_, _, _, _) => unreachable!(),
        Embed(_) => unreachable!(),
        Var(var) => match ctx.lookup(&var) {
            Some(e) => Ok(RetType(e.into_owned())),
            None => Err(mkerr(UnboundVariable(var.clone()))),
        },
        App(f, a) => {
            let tf = f.get_type()?;
            let tf_internal = tf.internal_whnf();
            let (x, tx, tb) = match &tf_internal {
                Some(Value::Pi(
                    x,
                    TypeThunk::Type(tx),
                    TypeThunk::Type(tb),
                )) => (x, tx, tb),
                Some(Value::Pi(_, _, _)) => {
                    panic!("ICE: this should not have happened")
                }
                _ => return Err(mkerr(NotAFunction(f.clone()))),
            };
            ensure_equal!(a.get_type()?, tx, {
                mkerr(TypeMismatch(f.clone(), tx.clone().to_normalized(), a))
            });

            Ok(RetType(tb.subst_shift(&x.into(), &a)))
        }
        Annot(x, t) => {
            let t = t.to_type();
            ensure_equal!(
                &t,
                x.get_type()?,
                mkerr(AnnotMismatch(x, t.to_normalized()))
            );
            Ok(RetType(x.get_type()?.into_owned()))
        }
        BoolIf(x, y, z) => {
            ensure_equal!(
                x.get_type()?,
                &builtin_to_type(Bool)?,
                mkerr(InvalidPredicate(x)),
            );

            ensure_simple_type!(
                y.get_type()?,
                mkerr(IfBranchMustBeTerm(true, y)),
            );

            ensure_simple_type!(
                z.get_type()?,
                mkerr(IfBranchMustBeTerm(false, z)),
            );

            ensure_equal!(
                y.get_type()?,
                z.get_type()?,
                mkerr(IfBranchMismatch(y, z))
            );

            Ok(RetType(y.get_type()?.into_owned()))
        }
        EmptyListLit(t) => {
            let t = t.to_type();
            Ok(RetType(
                TypeIntermediate::ListType(ctx.clone(), t)
                    .typecheck()?
                    .to_type(),
            ))
        }
        NEListLit(xs) => {
            let mut iter = xs.into_iter().enumerate();
            let (_, x) = iter.next().unwrap();
            for (i, y) in iter {
                ensure_equal!(
                    x.get_type()?,
                    y.get_type()?,
                    mkerr(InvalidListElement(
                        i,
                        x.get_type()?.to_normalized(),
                        y
                    ))
                );
            }
            let t = x.get_type()?.into_owned();
            Ok(RetType(
                TypeIntermediate::ListType(ctx.clone(), t)
                    .typecheck()?
                    .to_type(),
            ))
        }
        SomeLit(x) => {
            let t = x.get_type()?.into_owned();
            Ok(RetType(
                TypeIntermediate::OptionalType(ctx.clone(), t)
                    .typecheck()?
                    .to_type(),
            ))
        }
        RecordType(kts) => {
            let kts: BTreeMap<_, _> = kts
                .into_iter()
                .map(|(x, t)| Ok((x, t.to_type())))
                .collect::<Result<_, _>>()?;
            Ok(RetTyped(
                TypeIntermediate::RecordType(ctx.clone(), kts).typecheck()?,
            ))
        }
        UnionType(kts) => {
            let kts: BTreeMap<_, _> = kts
                .into_iter()
                .map(|(x, t)| {
                    Ok((
                        x,
                        match t {
                            None => None,
                            Some(t) => Some(t.to_type()),
                        },
                    ))
                })
                .collect::<Result<_, _>>()?;
            Ok(RetTyped(
                TypeIntermediate::UnionType(ctx.clone(), kts).typecheck()?,
            ))
        }
        RecordLit(kvs) => {
            let kts = kvs
                .into_iter()
                .map(|(x, v)| Ok((x, v.get_type()?.into_owned())))
                .collect::<Result<_, _>>()?;
            Ok(RetType(
                TypeIntermediate::RecordType(ctx.clone(), kts)
                    .typecheck()?
                    .to_type(),
            ))
        }
        UnionLit(x, v, kvs) => {
            let mut kts: std::collections::BTreeMap<_, _> = kvs
                .into_iter()
                .map(|(x, v)| {
                    let t = match v {
                        Some(x) => Some(x.to_type()),
                        None => None,
                    };
                    Ok((x, t))
                })
                .collect::<Result<_, _>>()?;
            let t = v.get_type()?.into_owned();
            kts.insert(x, Some(t));
            Ok(RetType(
                TypeIntermediate::UnionType(ctx.clone(), kts)
                    .typecheck()?
                    .to_type(),
            ))
        }
        Field(r, x) => {
            match &r.get_type()?.internal_whnf() {
                Some(Value::RecordType(kts)) => match kts.get(&x) {
                    Some(tth) => {
                        Ok(RetType(tth.to_type(ctx)?))
                    },
                    None => Err(mkerr(MissingRecordField(x, r.clone()))),
                },
                // TODO: branch here only when r.get_type() is a Const
                _ => {
                    let r = r.to_type();
                    match &r.internal_whnf() {
                        Some(Value::UnionType(kts)) => match kts.get(&x) {
                            // Constructor has type T -> < x: T, ... >
                            // TODO: use "_" instead of x (i.e. compare types using equivalence in tests)
                            Some(Some(t)) => {
                                Ok(RetType(
                                    TypeIntermediate::Pi(
                                        ctx.clone(),
                                        x.clone(),
                                        t.to_type(ctx)?,
                                        r.clone(),
                                    )
                                    .typecheck()?
                                    .to_type(),
                                ))
                            },
                            Some(None) => {
                                Ok(RetType(r.clone()))
                            },
                            None => {
                                Err(mkerr(MissingUnionField(
                                    x,
                                    r.to_normalized(),
                                )))
                            },
                        },
                        _ => {
                            Err(mkerr(NotARecord(
                                x,
                                r.to_normalized()
                            )))
                        },
                    }
                }
                // _ => Err(mkerr(NotARecord(
                //     x,
                //     r.to_type()?.to_normalized(),
                // ))),
            }
        }
        Const(c) => Ok(RetTyped(const_to_typed(c))),
        Builtin(b) => Ok(RetType(mktype(ctx, type_of_builtin(b))?)),
        BoolLit(_) => Ok(RetType(builtin_to_type(Bool)?)),
        NaturalLit(_) => Ok(RetType(builtin_to_type(Natural)?)),
        IntegerLit(_) => Ok(RetType(builtin_to_type(Integer)?)),
        DoubleLit(_) => Ok(RetType(builtin_to_type(Double)?)),
        TextLit(interpolated) => {
            let text_type = builtin_to_type(Text)?;
            for contents in interpolated.iter() {
                use InterpolatedTextContents::Expr;
                if let Expr(x) = contents {
                    ensure_equal!(
                        x.get_type()?,
                        &text_type,
                        mkerr(InvalidTextInterpolation(x)),
                    );
                }
            }
            Ok(RetType(text_type))
        }
        BinOp(o @ ListAppend, l, r) => {
            match l.get_type()?.internal_whnf() {
                Some(Value::AppliedBuiltin(List, _)) => {}
                _ => return Err(mkerr(BinOpTypeMismatch(o, l.clone()))),
            }

            ensure_equal!(
                l.get_type()?,
                r.get_type()?,
                mkerr(BinOpTypeMismatch(o, r))
            );

            Ok(RetType(l.get_type()?.into_owned()))
        }
        BinOp(o, l, r) => {
            let t = builtin_to_type(match o {
                BoolAnd => Bool,
                BoolOr => Bool,
                BoolEQ => Bool,
                BoolNE => Bool,
                NaturalPlus => Natural,
                NaturalTimes => Natural,
                TextAppend => Text,
                ListAppend => unreachable!(),
                _ => return Err(mkerr(Unimplemented)),
            })?;

            ensure_equal!(l.get_type()?, &t, mkerr(BinOpTypeMismatch(o, l)));

            ensure_equal!(r.get_type()?, &t, mkerr(BinOpTypeMismatch(o, r)));

            Ok(RetType(t))
        }
        _ => Err(mkerr(Unimplemented)),
    }
}

/// `typeOf` is the same as `type_with` with an empty context, meaning that the
/// expression must be closed (i.e. no free variables), otherwise type-checking
/// will fail.
fn type_of(e: InputSubExpr) -> Result<Typed, TypeError> {
    let ctx = TypecheckContext::new();
    let e = type_with(&ctx, e)?;
    // Ensure `e` has a type (i.e. `e` is not `Sort`)
    e.get_type()?;
    Ok(e)
}

/// The specific type error
#[derive(Debug)]
pub(crate) enum TypeMessage {
    UnboundVariable(Var<Label>),
    InvalidInputType(Normalized),
    InvalidOutputType(Normalized),
    NotAFunction(Typed),
    TypeMismatch(Typed, Normalized, Typed),
    AnnotMismatch(Typed, Normalized),
    Untyped,
    InvalidListElement(usize, Normalized, Typed),
    InvalidListType(Normalized),
    InvalidOptionalType(Normalized),
    InvalidPredicate(Typed),
    IfBranchMismatch(Typed, Typed),
    IfBranchMustBeTerm(bool, Typed),
    InvalidFieldType(Label, Type),
    NotARecord(Label, Normalized),
    MissingRecordField(Label, Typed),
    MissingUnionField(Label, Normalized),
    BinOpTypeMismatch(BinOp, Typed),
    NoDependentTypes(Normalized, Normalized),
    InvalidTextInterpolation(Typed),
    Sort,
    Unimplemented,
}

/// A structured type error that includes context
#[derive(Debug)]
pub struct TypeError {
    type_message: TypeMessage,
    context: TypecheckContext,
}

impl TypeError {
    pub(crate) fn new(
        context: &TypecheckContext,
        type_message: TypeMessage,
    ) -> Self {
        TypeError {
            context: context.clone(),
            type_message,
        }
    }
}

impl From<TypeError> for std::option::NoneError {
    fn from(_: TypeError) -> std::option::NoneError {
        std::option::NoneError
    }
}

impl ::std::error::Error for TypeMessage {
    fn description(&self) -> &str {
        match *self {
            // UnboundVariable => "Unbound variable",
            InvalidInputType(_) => "Invalid function input",
            InvalidOutputType(_) => "Invalid function output",
            NotAFunction(_) => "Not a function",
            TypeMismatch(_, _, _) => "Wrong type of function argument",
            _ => "Unhandled error",
        }
    }
}

impl fmt::Display for TypeMessage {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        match self {
            // UnboundVariable(_) => {
            //     f.write_str(include_str!("errors/UnboundVariable.txt"))
            // }
            // TypeMismatch(e0, e1, e2) => {
            //     let template = include_str!("errors/TypeMismatch.txt");
            //     let s = template
            //         .replace("$txt0", &format!("{}", e0.as_expr()))
            //         .replace("$txt1", &format!("{}", e1.as_expr()))
            //         .replace("$txt2", &format!("{}", e2.as_expr()))
            //         .replace(
            //             "$txt3",
            //             &format!(
            //                 "{}",
            //                 e2.get_type()
            //                     .unwrap()
            //                     .as_normalized()
            //                     .unwrap()
            //                     .as_expr()
            //             ),
            //         );
            //     f.write_str(&s)
            // }
            _ => f.write_str("Unhandled error message"),
        }
    }
}

#[cfg(test)]
mod spec_tests {
    #![rustfmt::skip]

    macro_rules! tc_success {
        ($name:ident, $path:expr) => {
            make_spec_test!(Typecheck, Success, $name, $path);
        };
    }
    macro_rules! tc_failure {
        ($name:ident, $path:expr) => {
            make_spec_test!(Typecheck, Failure, $name, $path);
        };
    }

    macro_rules! ti_success {
        ($name:ident, $path:expr) => {
            make_spec_test!(TypeInference, Success, $name, $path);
        };
    }
    // macro_rules! ti_failure {
    //     ($name:ident, $path:expr) => {
    //         make_spec_test!(TypeInference, Failure, $name, $path);
    //     };
    // }

    // tc_success!(tc_success_accessEncodedType, "accessEncodedType");
    // tc_success!(tc_success_accessType, "accessType");
    tc_success!(tc_success_prelude_Bool_and_0, "prelude/Bool/and/0");
    tc_success!(tc_success_prelude_Bool_and_1, "prelude/Bool/and/1");
    tc_success!(tc_success_prelude_Bool_build_0, "prelude/Bool/build/0");
    tc_success!(tc_success_prelude_Bool_build_1, "prelude/Bool/build/1");
    tc_success!(tc_success_prelude_Bool_even_0, "prelude/Bool/even/0");
    tc_success!(tc_success_prelude_Bool_even_1, "prelude/Bool/even/1");
    tc_success!(tc_success_prelude_Bool_even_2, "prelude/Bool/even/2");
    tc_success!(tc_success_prelude_Bool_even_3, "prelude/Bool/even/3");
    tc_success!(tc_success_prelude_Bool_fold_0, "prelude/Bool/fold/0");
    tc_success!(tc_success_prelude_Bool_fold_1, "prelude/Bool/fold/1");
    tc_success!(tc_success_prelude_Bool_not_0, "prelude/Bool/not/0");
    tc_success!(tc_success_prelude_Bool_not_1, "prelude/Bool/not/1");
    tc_success!(tc_success_prelude_Bool_odd_0, "prelude/Bool/odd/0");
    tc_success!(tc_success_prelude_Bool_odd_1, "prelude/Bool/odd/1");
    tc_success!(tc_success_prelude_Bool_odd_2, "prelude/Bool/odd/2");
    tc_success!(tc_success_prelude_Bool_odd_3, "prelude/Bool/odd/3");
    tc_success!(tc_success_prelude_Bool_or_0, "prelude/Bool/or/0");
    tc_success!(tc_success_prelude_Bool_or_1, "prelude/Bool/or/1");
    tc_success!(tc_success_prelude_Bool_show_0, "prelude/Bool/show/0");
    tc_success!(tc_success_prelude_Bool_show_1, "prelude/Bool/show/1");
    tc_success!(tc_success_prelude_Double_show_0, "prelude/Double/show/0");
    tc_success!(tc_success_prelude_Double_show_1, "prelude/Double/show/1");
    tc_success!(tc_success_prelude_Integer_show_0, "prelude/Integer/show/0");
    tc_success!(tc_success_prelude_Integer_show_1, "prelude/Integer/show/1");
    tc_success!(tc_success_prelude_Integer_toDouble_0, "prelude/Integer/toDouble/0");
    tc_success!(tc_success_prelude_Integer_toDouble_1, "prelude/Integer/toDouble/1");
    tc_success!(tc_success_prelude_List_all_0, "prelude/List/all/0");
    tc_success!(tc_success_prelude_List_all_1, "prelude/List/all/1");
    tc_success!(tc_success_prelude_List_any_0, "prelude/List/any/0");
    tc_success!(tc_success_prelude_List_any_1, "prelude/List/any/1");
    tc_success!(tc_success_prelude_List_build_0, "prelude/List/build/0");
    tc_success!(tc_success_prelude_List_build_1, "prelude/List/build/1");
    tc_success!(tc_success_prelude_List_concat_0, "prelude/List/concat/0");
    tc_success!(tc_success_prelude_List_concat_1, "prelude/List/concat/1");
    tc_success!(tc_success_prelude_List_concatMap_0, "prelude/List/concatMap/0");
    tc_success!(tc_success_prelude_List_concatMap_1, "prelude/List/concatMap/1");
    tc_success!(tc_success_prelude_List_filter_0, "prelude/List/filter/0");
    tc_success!(tc_success_prelude_List_filter_1, "prelude/List/filter/1");
    tc_success!(tc_success_prelude_List_fold_0, "prelude/List/fold/0");
    tc_success!(tc_success_prelude_List_fold_1, "prelude/List/fold/1");
    tc_success!(tc_success_prelude_List_fold_2, "prelude/List/fold/2");
    tc_success!(tc_success_prelude_List_generate_0, "prelude/List/generate/0");
    tc_success!(tc_success_prelude_List_generate_1, "prelude/List/generate/1");
    tc_success!(tc_success_prelude_List_head_0, "prelude/List/head/0");
    tc_success!(tc_success_prelude_List_head_1, "prelude/List/head/1");
    tc_success!(tc_success_prelude_List_indexed_0, "prelude/List/indexed/0");
    tc_success!(tc_success_prelude_List_indexed_1, "prelude/List/indexed/1");
    tc_success!(tc_success_prelude_List_iterate_0, "prelude/List/iterate/0");
    tc_success!(tc_success_prelude_List_iterate_1, "prelude/List/iterate/1");
    tc_success!(tc_success_prelude_List_last_0, "prelude/List/last/0");
    tc_success!(tc_success_prelude_List_last_1, "prelude/List/last/1");
    tc_success!(tc_success_prelude_List_length_0, "prelude/List/length/0");
    tc_success!(tc_success_prelude_List_length_1, "prelude/List/length/1");
    tc_success!(tc_success_prelude_List_map_0, "prelude/List/map/0");
    tc_success!(tc_success_prelude_List_map_1, "prelude/List/map/1");
    tc_success!(tc_success_prelude_List_null_0, "prelude/List/null/0");
    tc_success!(tc_success_prelude_List_null_1, "prelude/List/null/1");
    tc_success!(tc_success_prelude_List_replicate_0, "prelude/List/replicate/0");
    tc_success!(tc_success_prelude_List_replicate_1, "prelude/List/replicate/1");
    tc_success!(tc_success_prelude_List_reverse_0, "prelude/List/reverse/0");
    tc_success!(tc_success_prelude_List_reverse_1, "prelude/List/reverse/1");
    tc_success!(tc_success_prelude_List_shifted_0, "prelude/List/shifted/0");
    tc_success!(tc_success_prelude_List_shifted_1, "prelude/List/shifted/1");
    tc_success!(tc_success_prelude_List_unzip_0, "prelude/List/unzip/0");
    tc_success!(tc_success_prelude_List_unzip_1, "prelude/List/unzip/1");
    tc_success!(tc_success_prelude_Monoid_00, "prelude/Monoid/00");
    tc_success!(tc_success_prelude_Monoid_01, "prelude/Monoid/01");
    tc_success!(tc_success_prelude_Monoid_02, "prelude/Monoid/02");
    tc_success!(tc_success_prelude_Monoid_03, "prelude/Monoid/03");
    tc_success!(tc_success_prelude_Monoid_04, "prelude/Monoid/04");
    tc_success!(tc_success_prelude_Monoid_05, "prelude/Monoid/05");
    tc_success!(tc_success_prelude_Monoid_06, "prelude/Monoid/06");
    tc_success!(tc_success_prelude_Monoid_07, "prelude/Monoid/07");
    tc_success!(tc_success_prelude_Monoid_08, "prelude/Monoid/08");
    tc_success!(tc_success_prelude_Monoid_09, "prelude/Monoid/09");
    tc_success!(tc_success_prelude_Monoid_10, "prelude/Monoid/10");
    tc_success!(tc_success_prelude_Natural_build_0, "prelude/Natural/build/0");
    tc_success!(tc_success_prelude_Natural_build_1, "prelude/Natural/build/1");
    tc_success!(tc_success_prelude_Natural_enumerate_0, "prelude/Natural/enumerate/0");
    tc_success!(tc_success_prelude_Natural_enumerate_1, "prelude/Natural/enumerate/1");
    tc_success!(tc_success_prelude_Natural_even_0, "prelude/Natural/even/0");
    tc_success!(tc_success_prelude_Natural_even_1, "prelude/Natural/even/1");
    tc_success!(tc_success_prelude_Natural_fold_0, "prelude/Natural/fold/0");
    tc_success!(tc_success_prelude_Natural_fold_1, "prelude/Natural/fold/1");
    tc_success!(tc_success_prelude_Natural_fold_2, "prelude/Natural/fold/2");
    tc_success!(tc_success_prelude_Natural_isZero_0, "prelude/Natural/isZero/0");
    tc_success!(tc_success_prelude_Natural_isZero_1, "prelude/Natural/isZero/1");
    tc_success!(tc_success_prelude_Natural_odd_0, "prelude/Natural/odd/0");
    tc_success!(tc_success_prelude_Natural_odd_1, "prelude/Natural/odd/1");
    tc_success!(tc_success_prelude_Natural_product_0, "prelude/Natural/product/0");
    tc_success!(tc_success_prelude_Natural_product_1, "prelude/Natural/product/1");
    tc_success!(tc_success_prelude_Natural_show_0, "prelude/Natural/show/0");
    tc_success!(tc_success_prelude_Natural_show_1, "prelude/Natural/show/1");
    tc_success!(tc_success_prelude_Natural_sum_0, "prelude/Natural/sum/0");
    tc_success!(tc_success_prelude_Natural_sum_1, "prelude/Natural/sum/1");
    tc_success!(tc_success_prelude_Natural_toDouble_0, "prelude/Natural/toDouble/0");
    tc_success!(tc_success_prelude_Natural_toDouble_1, "prelude/Natural/toDouble/1");
    tc_success!(tc_success_prelude_Natural_toInteger_0, "prelude/Natural/toInteger/0");
    tc_success!(tc_success_prelude_Natural_toInteger_1, "prelude/Natural/toInteger/1");
    tc_success!(tc_success_prelude_Optional_all_0, "prelude/Optional/all/0");
    tc_success!(tc_success_prelude_Optional_all_1, "prelude/Optional/all/1");
    tc_success!(tc_success_prelude_Optional_any_0, "prelude/Optional/any/0");
    tc_success!(tc_success_prelude_Optional_any_1, "prelude/Optional/any/1");
    tc_success!(tc_success_prelude_Optional_build_0, "prelude/Optional/build/0");
    tc_success!(tc_success_prelude_Optional_build_1, "prelude/Optional/build/1");
    tc_success!(tc_success_prelude_Optional_concat_0, "prelude/Optional/concat/0");
    tc_success!(tc_success_prelude_Optional_concat_1, "prelude/Optional/concat/1");
    tc_success!(tc_success_prelude_Optional_concat_2, "prelude/Optional/concat/2");
    tc_success!(tc_success_prelude_Optional_filter_0, "prelude/Optional/filter/0");
    tc_success!(tc_success_prelude_Optional_filter_1, "prelude/Optional/filter/1");
    tc_success!(tc_success_prelude_Optional_fold_0, "prelude/Optional/fold/0");
    tc_success!(tc_success_prelude_Optional_fold_1, "prelude/Optional/fold/1");
    tc_success!(tc_success_prelude_Optional_head_0, "prelude/Optional/head/0");
    tc_success!(tc_success_prelude_Optional_head_1, "prelude/Optional/head/1");
    tc_success!(tc_success_prelude_Optional_head_2, "prelude/Optional/head/2");
    tc_success!(tc_success_prelude_Optional_last_0, "prelude/Optional/last/0");
    tc_success!(tc_success_prelude_Optional_last_1, "prelude/Optional/last/1");
    tc_success!(tc_success_prelude_Optional_last_2, "prelude/Optional/last/2");
    tc_success!(tc_success_prelude_Optional_length_0, "prelude/Optional/length/0");
    tc_success!(tc_success_prelude_Optional_length_1, "prelude/Optional/length/1");
    tc_success!(tc_success_prelude_Optional_map_0, "prelude/Optional/map/0");
    tc_success!(tc_success_prelude_Optional_map_1, "prelude/Optional/map/1");
    tc_success!(tc_success_prelude_Optional_null_0, "prelude/Optional/null/0");
    tc_success!(tc_success_prelude_Optional_null_1, "prelude/Optional/null/1");
    tc_success!(tc_success_prelude_Optional_toList_0, "prelude/Optional/toList/0");
    tc_success!(tc_success_prelude_Optional_toList_1, "prelude/Optional/toList/1");
    tc_success!(tc_success_prelude_Optional_unzip_0, "prelude/Optional/unzip/0");
    tc_success!(tc_success_prelude_Optional_unzip_1, "prelude/Optional/unzip/1");
    tc_success!(tc_success_prelude_Text_concat_0, "prelude/Text/concat/0");
    tc_success!(tc_success_prelude_Text_concat_1, "prelude/Text/concat/1");
    tc_success!(tc_success_prelude_Text_concatMap_0, "prelude/Text/concatMap/0");
    tc_success!(tc_success_prelude_Text_concatMap_1, "prelude/Text/concatMap/1");
    // tc_success!(tc_success_prelude_Text_concatMapSep_0, "prelude/Text/concatMapSep/0");
    // tc_success!(tc_success_prelude_Text_concatMapSep_1, "prelude/Text/concatMapSep/1");
    // tc_success!(tc_success_prelude_Text_concatSep_0, "prelude/Text/concatSep/0");
    // tc_success!(tc_success_prelude_Text_concatSep_1, "prelude/Text/concatSep/1");
    tc_success!(tc_success_recordOfRecordOfTypes, "recordOfRecordOfTypes");
    tc_success!(tc_success_recordOfTypes, "recordOfTypes");
    // tc_success!(tc_success_simple_access_0, "simple/access/0");
    // tc_success!(tc_success_simple_access_1, "simple/access/1");
    // tc_success!(tc_success_simple_alternativesAreTypes, "simple/alternativesAreTypes");
    // tc_success!(tc_success_simple_anonymousFunctionsInTypes, "simple/anonymousFunctionsInTypes");
    // tc_success!(tc_success_simple_fieldsAreTypes, "simple/fieldsAreTypes");
    // tc_success!(tc_success_simple_kindParameter, "simple/kindParameter");
    // tc_success!(tc_success_simple_mergeEquivalence, "simple/mergeEquivalence");
    // tc_success!(tc_success_simple_mixedFieldAccess, "simple/mixedFieldAccess");
    tc_success!(tc_success_simple_unionsOfTypes, "simple/unionsOfTypes");

    tc_failure!(tc_failure_combineMixedRecords, "combineMixedRecords");
    // tc_failure!(tc_failure_duplicateFields, "duplicateFields");
    tc_failure!(tc_failure_hurkensParadox, "hurkensParadox");
    tc_failure!(tc_failure_mixedUnions, "mixedUnions");
    tc_failure!(tc_failure_preferMixedRecords, "preferMixedRecords");
    tc_failure!(tc_failure_unit_FunctionApplicationArgumentNotMatch, "unit/FunctionApplicationArgumentNotMatch");
    tc_failure!(tc_failure_unit_FunctionApplicationIsNotFunction, "unit/FunctionApplicationIsNotFunction");
    tc_failure!(tc_failure_unit_FunctionArgumentTypeNotAType, "unit/FunctionArgumentTypeNotAType");
    tc_failure!(tc_failure_unit_FunctionDependentType, "unit/FunctionDependentType");
    tc_failure!(tc_failure_unit_FunctionDependentType2, "unit/FunctionDependentType2");
    tc_failure!(tc_failure_unit_FunctionTypeArgumentTypeNotAType, "unit/FunctionTypeArgumentTypeNotAType");
    tc_failure!(tc_failure_unit_FunctionTypeKindSort, "unit/FunctionTypeKindSort");
    tc_failure!(tc_failure_unit_FunctionTypeTypeKind, "unit/FunctionTypeTypeKind");
    tc_failure!(tc_failure_unit_FunctionTypeTypeSort, "unit/FunctionTypeTypeSort");
    tc_failure!(tc_failure_unit_IfBranchesNotMatch, "unit/IfBranchesNotMatch");
    tc_failure!(tc_failure_unit_IfBranchesNotType, "unit/IfBranchesNotType");
    tc_failure!(tc_failure_unit_IfNotBool, "unit/IfNotBool");
    tc_failure!(tc_failure_unit_LetWithWrongAnnotation, "unit/LetWithWrongAnnotation");
    tc_failure!(tc_failure_unit_ListLiteralEmptyNotType, "unit/ListLiteralEmptyNotType");
    tc_failure!(tc_failure_unit_ListLiteralNotType, "unit/ListLiteralNotType");
    tc_failure!(tc_failure_unit_ListLiteralTypesNotMatch, "unit/ListLiteralTypesNotMatch");
    tc_failure!(tc_failure_unit_MergeAlternativeHasNoHandler, "unit/MergeAlternativeHasNoHandler");
    tc_failure!(tc_failure_unit_MergeAnnotationNotType, "unit/MergeAnnotationNotType");
    tc_failure!(tc_failure_unit_MergeEmptyWithoutAnnotation, "unit/MergeEmptyWithoutAnnotation");
    tc_failure!(tc_failure_unit_MergeHandlerNotFunction, "unit/MergeHandlerNotFunction");
    tc_failure!(tc_failure_unit_MergeHandlerNotInUnion, "unit/MergeHandlerNotInUnion");
    tc_failure!(tc_failure_unit_MergeHandlerNotMatchAlternativeType, "unit/MergeHandlerNotMatchAlternativeType");
    tc_failure!(tc_failure_unit_MergeHandlersWithDifferentType, "unit/MergeHandlersWithDifferentType");
    tc_failure!(tc_failure_unit_MergeLhsNotRecord, "unit/MergeLhsNotRecord");
    tc_failure!(tc_failure_unit_MergeRhsNotUnion, "unit/MergeRhsNotUnion");
    tc_failure!(tc_failure_unit_MergeWithWrongAnnotation, "unit/MergeWithWrongAnnotation");
    tc_failure!(tc_failure_unit_OperatorAndNotBool, "unit/OperatorAndNotBool");
    tc_failure!(tc_failure_unit_OperatorEqualNotBool, "unit/OperatorEqualNotBool");
    tc_failure!(tc_failure_unit_OperatorListConcatenateLhsNotList, "unit/OperatorListConcatenateLhsNotList");
    tc_failure!(tc_failure_unit_OperatorListConcatenateListsNotMatch, "unit/OperatorListConcatenateListsNotMatch");
    tc_failure!(tc_failure_unit_OperatorListConcatenateRhsNotList, "unit/OperatorListConcatenateRhsNotList");
    tc_failure!(tc_failure_unit_OperatorNotEqualNotBool, "unit/OperatorNotEqualNotBool");
    tc_failure!(tc_failure_unit_OperatorOrNotBool, "unit/OperatorOrNotBool");
    tc_failure!(tc_failure_unit_OperatorPlusNotNatural, "unit/OperatorPlusNotNatural");
    tc_failure!(tc_failure_unit_OperatorTextConcatenateLhsNotText, "unit/OperatorTextConcatenateLhsNotText");
    tc_failure!(tc_failure_unit_OperatorTextConcatenateRhsNotText, "unit/OperatorTextConcatenateRhsNotText");
    tc_failure!(tc_failure_unit_OperatorTimesNotNatural, "unit/OperatorTimesNotNatural");
    tc_failure!(tc_failure_unit_RecordMixedKinds, "unit/RecordMixedKinds");
    tc_failure!(tc_failure_unit_RecordMixedKinds2, "unit/RecordMixedKinds2");
    tc_failure!(tc_failure_unit_RecordMixedKinds3, "unit/RecordMixedKinds3");
    tc_failure!(tc_failure_unit_RecordProjectionEmpty, "unit/RecordProjectionEmpty");
    tc_failure!(tc_failure_unit_RecordProjectionNotPresent, "unit/RecordProjectionNotPresent");
    tc_failure!(tc_failure_unit_RecordProjectionNotRecord, "unit/RecordProjectionNotRecord");
    tc_failure!(tc_failure_unit_RecordSelectionEmpty, "unit/RecordSelectionEmpty");
    tc_failure!(tc_failure_unit_RecordSelectionNotPresent, "unit/RecordSelectionNotPresent");
    tc_failure!(tc_failure_unit_RecordSelectionNotRecord, "unit/RecordSelectionNotRecord");
    tc_failure!(tc_failure_unit_RecordSelectionTypeNotUnionType, "unit/RecordSelectionTypeNotUnionType");
    tc_failure!(tc_failure_unit_RecordTypeMixedKinds, "unit/RecordTypeMixedKinds");
    tc_failure!(tc_failure_unit_RecordTypeMixedKinds2, "unit/RecordTypeMixedKinds2");
    tc_failure!(tc_failure_unit_RecordTypeMixedKinds3, "unit/RecordTypeMixedKinds3");
    tc_failure!(tc_failure_unit_RecordTypeValueMember, "unit/RecordTypeValueMember");
    tc_failure!(tc_failure_unit_RecursiveRecordMergeLhsNotRecord, "unit/RecursiveRecordMergeLhsNotRecord");
    tc_failure!(tc_failure_unit_RecursiveRecordMergeMixedKinds, "unit/RecursiveRecordMergeMixedKinds");
    tc_failure!(tc_failure_unit_RecursiveRecordMergeOverlapping, "unit/RecursiveRecordMergeOverlapping");
    tc_failure!(tc_failure_unit_RecursiveRecordMergeRhsNotRecord, "unit/RecursiveRecordMergeRhsNotRecord");
    tc_failure!(tc_failure_unit_RecursiveRecordTypeMergeLhsNotRecordType, "unit/RecursiveRecordTypeMergeLhsNotRecordType");
    tc_failure!(tc_failure_unit_RecursiveRecordTypeMergeOverlapping, "unit/RecursiveRecordTypeMergeOverlapping");
    tc_failure!(tc_failure_unit_RecursiveRecordTypeMergeRhsNotRecordType, "unit/RecursiveRecordTypeMergeRhsNotRecordType");
    tc_failure!(tc_failure_unit_RightBiasedRecordMergeLhsNotRecord, "unit/RightBiasedRecordMergeLhsNotRecord");
    tc_failure!(tc_failure_unit_RightBiasedRecordMergeMixedKinds, "unit/RightBiasedRecordMergeMixedKinds");
    tc_failure!(tc_failure_unit_RightBiasedRecordMergeMixedKinds2, "unit/RightBiasedRecordMergeMixedKinds2");
    tc_failure!(tc_failure_unit_RightBiasedRecordMergeMixedKinds3, "unit/RightBiasedRecordMergeMixedKinds3");
    tc_failure!(tc_failure_unit_RightBiasedRecordMergeRhsNotRecord, "unit/RightBiasedRecordMergeRhsNotRecord");
    tc_failure!(tc_failure_unit_SomeNotType, "unit/SomeNotType");
    tc_failure!(tc_failure_unit_Sort, "unit/Sort");
    tc_failure!(tc_failure_unit_TextLiteralInterpolateNotText, "unit/TextLiteralInterpolateNotText");
    tc_failure!(tc_failure_unit_TypeAnnotationWrong, "unit/TypeAnnotationWrong");
    tc_failure!(tc_failure_unit_UnionConstructorFieldNotPresent, "unit/UnionConstructorFieldNotPresent");
    tc_failure!(tc_failure_unit_UnionTypeMixedKinds, "unit/UnionTypeMixedKinds");
    tc_failure!(tc_failure_unit_UnionTypeMixedKinds2, "unit/UnionTypeMixedKinds2");
    tc_failure!(tc_failure_unit_UnionTypeMixedKinds3, "unit/UnionTypeMixedKinds3");
    tc_failure!(tc_failure_unit_UnionTypeNotType, "unit/UnionTypeNotType");
    tc_failure!(tc_failure_unit_VariableFree, "unit/VariableFree");

    // ti_success!(ti_success_simple_alternativesAreTypes, "simple/alternativesAreTypes");
    // ti_success!(ti_success_simple_kindParameter, "simple/kindParameter");
    ti_success!(ti_success_unit_Bool, "unit/Bool");
    ti_success!(ti_success_unit_Double, "unit/Double");
    ti_success!(ti_success_unit_DoubleLiteral, "unit/DoubleLiteral");
    ti_success!(ti_success_unit_DoubleShow, "unit/DoubleShow");
    ti_success!(ti_success_unit_False, "unit/False");
    ti_success!(ti_success_unit_Function, "unit/Function");
    ti_success!(ti_success_unit_FunctionApplication, "unit/FunctionApplication");
    ti_success!(ti_success_unit_FunctionNamedArg, "unit/FunctionNamedArg");
    ti_success!(ti_success_unit_FunctionTypeKindKind, "unit/FunctionTypeKindKind");
    ti_success!(ti_success_unit_FunctionTypeKindTerm, "unit/FunctionTypeKindTerm");
    ti_success!(ti_success_unit_FunctionTypeKindType, "unit/FunctionTypeKindType");
    ti_success!(ti_success_unit_FunctionTypeTermTerm, "unit/FunctionTypeTermTerm");
    ti_success!(ti_success_unit_FunctionTypeTypeTerm, "unit/FunctionTypeTypeTerm");
    ti_success!(ti_success_unit_FunctionTypeTypeType, "unit/FunctionTypeTypeType");
    ti_success!(ti_success_unit_FunctionTypeUsingArgument, "unit/FunctionTypeUsingArgument");
    ti_success!(ti_success_unit_If, "unit/If");
    ti_success!(ti_success_unit_IfNormalizeArguments, "unit/IfNormalizeArguments");
    ti_success!(ti_success_unit_Integer, "unit/Integer");
    ti_success!(ti_success_unit_IntegerLiteral, "unit/IntegerLiteral");
    ti_success!(ti_success_unit_IntegerShow, "unit/IntegerShow");
    ti_success!(ti_success_unit_IntegerToDouble, "unit/IntegerToDouble");
    ti_success!(ti_success_unit_Kind, "unit/Kind");
    ti_success!(ti_success_unit_Let, "unit/Let");
    ti_success!(ti_success_unit_LetNestedTypeSynonym, "unit/LetNestedTypeSynonym");
    ti_success!(ti_success_unit_LetTypeSynonym, "unit/LetTypeSynonym");
    ti_success!(ti_success_unit_LetWithAnnotation, "unit/LetWithAnnotation");
    ti_success!(ti_success_unit_List, "unit/List");
    ti_success!(ti_success_unit_ListBuild, "unit/ListBuild");
    ti_success!(ti_success_unit_ListFold, "unit/ListFold");
    ti_success!(ti_success_unit_ListHead, "unit/ListHead");
    ti_success!(ti_success_unit_ListIndexed, "unit/ListIndexed");
    ti_success!(ti_success_unit_ListLast, "unit/ListLast");
    ti_success!(ti_success_unit_ListLength, "unit/ListLength");
    ti_success!(ti_success_unit_ListLiteralEmpty, "unit/ListLiteralEmpty");
    ti_success!(ti_success_unit_ListLiteralNormalizeArguments, "unit/ListLiteralNormalizeArguments");
    ti_success!(ti_success_unit_ListLiteralOne, "unit/ListLiteralOne");
    ti_success!(ti_success_unit_ListReverse, "unit/ListReverse");
    // ti_success!(ti_success_unit_MergeEmptyUnion, "unit/MergeEmptyUnion");
    // ti_success!(ti_success_unit_MergeOne, "unit/MergeOne");
    // ti_success!(ti_success_unit_MergeOneWithAnnotation, "unit/MergeOneWithAnnotation");
    ti_success!(ti_success_unit_Natural, "unit/Natural");
    ti_success!(ti_success_unit_NaturalBuild, "unit/NaturalBuild");
    ti_success!(ti_success_unit_NaturalEven, "unit/NaturalEven");
    ti_success!(ti_success_unit_NaturalFold, "unit/NaturalFold");
    ti_success!(ti_success_unit_NaturalIsZero, "unit/NaturalIsZero");
    ti_success!(ti_success_unit_NaturalLiteral, "unit/NaturalLiteral");
    ti_success!(ti_success_unit_NaturalOdd, "unit/NaturalOdd");
    ti_success!(ti_success_unit_NaturalShow, "unit/NaturalShow");
    ti_success!(ti_success_unit_NaturalToInteger, "unit/NaturalToInteger");
    ti_success!(ti_success_unit_None, "unit/None");
    ti_success!(ti_success_unit_OldOptionalNone, "unit/OldOptionalNone");
    ti_success!(ti_success_unit_OldOptionalTrue, "unit/OldOptionalTrue");
    ti_success!(ti_success_unit_OperatorAnd, "unit/OperatorAnd");
    ti_success!(ti_success_unit_OperatorAndNormalizeArguments, "unit/OperatorAndNormalizeArguments");
    ti_success!(ti_success_unit_OperatorEqual, "unit/OperatorEqual");
    ti_success!(ti_success_unit_OperatorEqualNormalizeArguments, "unit/OperatorEqualNormalizeArguments");
    ti_success!(ti_success_unit_OperatorListConcatenate, "unit/OperatorListConcatenate");
    ti_success!(ti_success_unit_OperatorListConcatenateNormalizeArguments, "unit/OperatorListConcatenateNormalizeArguments");
    ti_success!(ti_success_unit_OperatorNotEqual, "unit/OperatorNotEqual");
    ti_success!(ti_success_unit_OperatorNotEqualNormalizeArguments, "unit/OperatorNotEqualNormalizeArguments");
    ti_success!(ti_success_unit_OperatorOr, "unit/OperatorOr");
    ti_success!(ti_success_unit_OperatorOrNormalizeArguments, "unit/OperatorOrNormalizeArguments");
    ti_success!(ti_success_unit_OperatorPlus, "unit/OperatorPlus");
    ti_success!(ti_success_unit_OperatorPlusNormalizeArguments, "unit/OperatorPlusNormalizeArguments");
    ti_success!(ti_success_unit_OperatorTextConcatenate, "unit/OperatorTextConcatenate");
    ti_success!(ti_success_unit_OperatorTextConcatenateNormalizeArguments, "unit/OperatorTextConcatenateNormalizeArguments");
    ti_success!(ti_success_unit_OperatorTimes, "unit/OperatorTimes");
    ti_success!(ti_success_unit_OperatorTimesNormalizeArguments, "unit/OperatorTimesNormalizeArguments");
    ti_success!(ti_success_unit_Optional, "unit/Optional");
    ti_success!(ti_success_unit_OptionalBuild, "unit/OptionalBuild");
    ti_success!(ti_success_unit_OptionalFold, "unit/OptionalFold");
    ti_success!(ti_success_unit_RecordEmpty, "unit/RecordEmpty");
    ti_success!(ti_success_unit_RecordOneKind, "unit/RecordOneKind");
    ti_success!(ti_success_unit_RecordOneType, "unit/RecordOneType");
    ti_success!(ti_success_unit_RecordOneValue, "unit/RecordOneValue");
    // ti_success!(ti_success_unit_RecordProjectionEmpty, "unit/RecordProjectionEmpty");
    // ti_success!(ti_success_unit_RecordProjectionKind, "unit/RecordProjectionKind");
    // ti_success!(ti_success_unit_RecordProjectionType, "unit/RecordProjectionType");
    // ti_success!(ti_success_unit_RecordProjectionValue, "unit/RecordProjectionValue");
    // ti_success!(ti_success_unit_RecordSelectionKind, "unit/RecordSelectionKind");
    // ti_success!(ti_success_unit_RecordSelectionType, "unit/RecordSelectionType");
    ti_success!(ti_success_unit_RecordSelectionValue, "unit/RecordSelectionValue");
    ti_success!(ti_success_unit_RecordType, "unit/RecordType");
    ti_success!(ti_success_unit_RecordTypeEmpty, "unit/RecordTypeEmpty");
    ti_success!(ti_success_unit_RecordTypeKind, "unit/RecordTypeKind");
    ti_success!(ti_success_unit_RecordTypeType, "unit/RecordTypeType");
    // ti_success!(ti_success_unit_RecursiveRecordMergeLhsEmpty, "unit/RecursiveRecordMergeLhsEmpty");
    // ti_success!(ti_success_unit_RecursiveRecordMergeRecursively, "unit/RecursiveRecordMergeRecursively");
    // ti_success!(ti_success_unit_RecursiveRecordMergeRecursivelyTypes, "unit/RecursiveRecordMergeRecursivelyTypes");
    // ti_success!(ti_success_unit_RecursiveRecordMergeRhsEmpty, "unit/RecursiveRecordMergeRhsEmpty");
    // ti_success!(ti_success_unit_RecursiveRecordMergeTwo, "unit/RecursiveRecordMergeTwo");
    // ti_success!(ti_success_unit_RecursiveRecordMergeTwoKinds, "unit/RecursiveRecordMergeTwoKinds");
    // ti_success!(ti_success_unit_RecursiveRecordMergeTwoTypes, "unit/RecursiveRecordMergeTwoTypes");
    // ti_success!(ti_success_unit_RecursiveRecordTypeMergeRecursively, "unit/RecursiveRecordTypeMergeRecursively");
    // ti_success!(ti_success_unit_RecursiveRecordTypeMergeRecursivelyTypes, "unit/RecursiveRecordTypeMergeRecursivelyTypes");
    // ti_success!(ti_success_unit_RecursiveRecordTypeMergeRhsEmpty, "unit/RecursiveRecordTypeMergeRhsEmpty");
    // ti_success!(ti_success_unit_RecursiveRecordTypeMergeTwo, "unit/RecursiveRecordTypeMergeTwo");
    // ti_success!(ti_success_unit_RecursiveRecordTypeMergeTwoKinds, "unit/RecursiveRecordTypeMergeTwoKinds");
    // ti_success!(ti_success_unit_RecursiveRecordTypeMergeTwoTypes, "unit/RecursiveRecordTypeMergeTwoTypes");
    // ti_success!(ti_success_unit_RightBiasedRecordMergeRhsEmpty, "unit/RightBiasedRecordMergeRhsEmpty");
    // ti_success!(ti_success_unit_RightBiasedRecordMergeTwo, "unit/RightBiasedRecordMergeTwo");
    // ti_success!(ti_success_unit_RightBiasedRecordMergeTwoDifferent, "unit/RightBiasedRecordMergeTwoDifferent");
    // ti_success!(ti_success_unit_RightBiasedRecordMergeTwoKinds, "unit/RightBiasedRecordMergeTwoKinds");
    // ti_success!(ti_success_unit_RightBiasedRecordMergeTwoTypes, "unit/RightBiasedRecordMergeTwoTypes");
    ti_success!(ti_success_unit_SomeTrue, "unit/SomeTrue");
    ti_success!(ti_success_unit_Text, "unit/Text");
    ti_success!(ti_success_unit_TextLiteral, "unit/TextLiteral");
    ti_success!(ti_success_unit_TextLiteralNormalizeArguments, "unit/TextLiteralNormalizeArguments");
    ti_success!(ti_success_unit_TextLiteralWithInterpolation, "unit/TextLiteralWithInterpolation");
    ti_success!(ti_success_unit_TextShow, "unit/TextShow");
    ti_success!(ti_success_unit_True, "unit/True");
    ti_success!(ti_success_unit_Type, "unit/Type");
    ti_success!(ti_success_unit_TypeAnnotation, "unit/TypeAnnotation");
    ti_success!(ti_success_unit_TypeAnnotationSort, "unit/TypeAnnotationSort");
    ti_success!(ti_success_unit_UnionConstructorField, "unit/UnionConstructorField");
    ti_success!(ti_success_unit_UnionOne, "unit/UnionOne");
    ti_success!(ti_success_unit_UnionTypeEmpty, "unit/UnionTypeEmpty");
    ti_success!(ti_success_unit_UnionTypeKind, "unit/UnionTypeKind");
    ti_success!(ti_success_unit_UnionTypeOne, "unit/UnionTypeOne");
    ti_success!(ti_success_unit_UnionTypeType, "unit/UnionTypeType");
}