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|
use crate::imports::ImportRoot;
use crate::normalize::{Thunk, Value};
use dhall_core::*;
use std::marker::PhantomData;
macro_rules! derive_other_traits {
($ty:ident) => {
impl<'a> std::cmp::PartialEq for $ty<'a> {
fn eq(&self, other: &Self) -> bool {
self.0 == other.0
}
}
impl<'a> std::cmp::Eq for $ty<'a> {}
impl<'a> std::fmt::Display for $ty<'a> {
fn fmt(
&self,
f: &mut std::fmt::Formatter,
) -> Result<(), std::fmt::Error> {
self.0.fmt(f)
}
}
};
}
#[derive(Debug, Clone)]
pub(crate) struct Parsed<'a>(
pub(crate) SubExpr<Span<'a>, Import>,
pub(crate) ImportRoot,
);
derive_other_traits!(Parsed);
#[derive(Debug, Clone)]
pub(crate) struct Resolved<'a>(
pub(crate) SubExpr<Span<'a>, Normalized<'static>>,
);
derive_other_traits!(Resolved);
pub(crate) use self::typed::TypedInternal;
#[derive(Debug, Clone)]
pub(crate) struct Typed<'a>(
pub(crate) TypedInternal,
pub(crate) PhantomData<&'a ()>,
);
#[derive(Debug, Clone)]
pub(crate) struct Normalized<'a>(
pub(crate) TypedInternal,
pub(crate) PhantomData<&'a ()>,
);
impl<'a> std::cmp::PartialEq for Normalized<'a> {
fn eq(&self, other: &Self) -> bool {
self.to_expr() == other.to_expr()
}
}
impl<'a> std::cmp::Eq for Normalized<'a> {}
impl<'a> std::fmt::Display for Normalized<'a> {
fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
self.to_expr().fmt(f)
}
}
mod typed {
use super::{Type, Typed};
use crate::normalize::{Thunk, Value};
use crate::typecheck::{
TypeError, TypeInternal, TypeMessage, TypecheckContext,
};
use dhall_core::{Const, Label, SubExpr, V, X};
use std::borrow::Cow;
use std::marker::PhantomData;
#[derive(Debug, Clone)]
pub(crate) enum TypedInternal {
// The `Sort` higher-kinded type doesn't have a type
Sort,
// Any other value, along with its type
Value(Thunk, Option<Type<'static>>),
}
impl TypedInternal {
pub(crate) fn from_thunk_and_type(th: Thunk, t: Type<'static>) -> Self {
TypedInternal::Value(th, Some(t))
}
pub(crate) fn from_thunk_untyped(th: Thunk) -> Self {
TypedInternal::Value(th, None)
}
// TODO: Avoid cloning if possible
pub(crate) fn to_value(&self) -> Value {
match self {
TypedInternal::Value(th, _) => th.normalize_whnf().clone(),
TypedInternal::Sort => Value::Const(Const::Sort),
}
}
pub(crate) fn to_expr(&self) -> SubExpr<X, X> {
self.to_value().normalize_to_expr()
}
pub(crate) fn to_thunk(&self) -> Thunk {
match self {
TypedInternal::Value(th, _) => th.clone(),
TypedInternal::Sort => {
Thunk::from_whnf(Value::Const(Const::Sort))
}
}
}
pub(crate) fn to_type(&self) -> Type<'static> {
match self {
TypedInternal::Sort => Type(TypeInternal::Const(Const::Sort)),
TypedInternal::Value(th, _) => match &*th.normalize_whnf() {
Value::Const(c) => Type(TypeInternal::Const(*c)),
_ => Type(TypeInternal::Typed(Box::new(Typed(
self.clone(),
PhantomData,
)))),
},
}
}
pub(crate) fn get_type(
&self,
) -> Result<Cow<'_, Type<'static>>, TypeError> {
match self {
TypedInternal::Value(_, Some(t)) => Ok(Cow::Borrowed(t)),
TypedInternal::Value(_, None) => Err(TypeError::new(
&TypecheckContext::new(),
TypeMessage::Untyped,
)),
TypedInternal::Sort => Err(TypeError::new(
&TypecheckContext::new(),
TypeMessage::Sort,
)),
}
}
pub(crate) fn shift(&self, delta: isize, var: &V<Label>) -> Self {
match self {
TypedInternal::Value(th, t) => TypedInternal::Value(
th.shift(delta, var),
t.as_ref().map(|x| x.shift(delta, var)),
),
TypedInternal::Sort => TypedInternal::Sort,
}
}
pub(crate) fn subst_shift(
&self,
var: &V<Label>,
val: &Typed<'static>,
) -> Self {
match self {
TypedInternal::Value(th, t) => TypedInternal::Value(
th.subst_shift(var, val),
t.as_ref().map(|x| x.subst_shift(var, val)),
),
TypedInternal::Sort => TypedInternal::Sort,
}
}
}
}
/// A Dhall expression representing a simple type.
///
/// This captures what is usually simply called a "type", like
/// `Bool`, `{ x: Integer }` or `Natural -> Text`.
///
/// For a more general notion of "type", see [Type].
#[derive(Debug, Clone)]
pub struct SimpleType<'a>(
pub(crate) SubExpr<X, X>,
pub(crate) PhantomData<&'a ()>,
);
derive_other_traits!(SimpleType);
pub(crate) use crate::typecheck::TypeInternal;
/// A Dhall expression representing a (possibly higher-kinded) type.
///
/// This includes [SimpleType]s but also higher-kinded expressions like
/// `Type`, `Kind` and `{ x: Type }`.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Type<'a>(pub(crate) TypeInternal<'a>);
impl<'a> std::fmt::Display for Type<'a> {
fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
self.to_normalized().fmt(f)
}
}
// Exposed for the macros
#[doc(hidden)]
impl<'a> From<SimpleType<'a>> for SubExpr<X, X> {
fn from(x: SimpleType<'a>) -> SubExpr<X, X> {
x.0
}
}
// Exposed for the macros
#[doc(hidden)]
impl<'a> From<SubExpr<X, X>> for SimpleType<'a> {
fn from(x: SubExpr<X, X>) -> SimpleType<'a> {
SimpleType(x, PhantomData)
}
}
// Exposed for the macros
#[doc(hidden)]
impl<'a> From<Normalized<'a>> for Typed<'a> {
fn from(x: Normalized<'a>) -> Typed<'a> {
Typed(x.0, x.1)
}
}
impl<'a> Normalized<'a> {
pub(crate) fn from_thunk_and_type(th: Thunk, t: Type<'static>) -> Self {
Normalized(TypedInternal::from_thunk_and_type(th, t), PhantomData)
}
// Deprecated
pub(crate) fn as_expr(&self) -> SubExpr<X, X> {
self.0.to_expr()
}
pub(crate) fn to_expr(&self) -> SubExpr<X, X> {
self.0.to_expr()
}
pub(crate) fn to_value(&self) -> Value {
self.0.to_value()
}
#[allow(dead_code)]
pub(crate) fn unnote<'b>(self) -> Normalized<'b> {
Normalized(self.0, PhantomData)
}
}
impl<'a> Typed<'a> {
pub(crate) fn from_thunk_and_type(th: Thunk, t: Type<'static>) -> Self {
Typed(TypedInternal::from_thunk_and_type(th, t), PhantomData)
}
pub(crate) fn from_thunk_untyped(th: Thunk) -> Self {
Typed(TypedInternal::from_thunk_untyped(th), PhantomData)
}
pub(crate) fn const_sort() -> Self {
Typed(TypedInternal::Sort, PhantomData)
}
}
|
