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-rw-r--r--dhall/src/semantics/parse.rs (renamed from dhall/src/semantics/phase/parse.rs)4
-rw-r--r--dhall/src/semantics/phase/mod.rs259
-rw-r--r--dhall/src/semantics/phase/normalize.rs791
-rw-r--r--dhall/src/semantics/phase/typecheck.rs838
-rw-r--r--dhall/src/semantics/resolve.rs (renamed from dhall/src/semantics/phase/resolve.rs)2
5 files changed, 3 insertions, 1891 deletions
diff --git a/dhall/src/semantics/phase/parse.rs b/dhall/src/semantics/parse.rs
index 00db422..ee35536 100644
--- a/dhall/src/semantics/phase/parse.rs
+++ b/dhall/src/semantics/parse.rs
@@ -3,10 +3,10 @@ use std::io::Read;
use std::path::Path;
use crate::error::Error;
-use crate::semantics::phase::resolve::ImportRoot;
-use crate::semantics::phase::Parsed;
+use crate::semantics::resolve::ImportRoot;
use crate::syntax::binary;
use crate::syntax::parse_expr;
+use crate::Parsed;
pub(crate) fn parse_file(f: &Path) -> Result<Parsed, Error> {
let mut buffer = String::new();
diff --git a/dhall/src/semantics/phase/mod.rs b/dhall/src/semantics/phase/mod.rs
deleted file mode 100644
index 5332eb3..0000000
--- a/dhall/src/semantics/phase/mod.rs
+++ /dev/null
@@ -1,259 +0,0 @@
-use std::fmt::Display;
-use std::path::Path;
-
-use crate::error::{EncodeError, Error, ImportError, TypeError};
-use crate::semantics::core::value::Value;
-use crate::semantics::core::value::ValueKind;
-use crate::semantics::core::var::{AlphaVar, Shift, Subst};
-use crate::semantics::to_expr::ToExprOptions;
-use crate::syntax::binary;
-use crate::syntax::{Builtin, Const, Expr};
-use resolve::ImportRoot;
-
-pub(crate) mod normalize;
-pub(crate) mod parse;
-pub(crate) mod resolve;
-pub(crate) mod typecheck;
-
-pub type ParsedExpr = Expr<Normalized>;
-pub type DecodedExpr = Expr<Normalized>;
-pub type ResolvedExpr = Expr<Normalized>;
-pub type NormalizedExpr = Expr<Normalized>;
-
-#[derive(Debug, Clone)]
-pub struct Parsed(ParsedExpr, ImportRoot);
-
-/// An expression where all imports have been resolved
-///
-/// Invariant: there must be no `Import` nodes or `ImportAlt` operations left.
-#[derive(Debug, Clone)]
-pub struct Resolved(ResolvedExpr);
-
-/// A typed expression
-#[derive(Debug, Clone)]
-pub struct Typed(Value);
-
-/// A normalized expression.
-///
-/// Invariant: the contained Typed expression must be in normal form,
-#[derive(Debug, Clone)]
-pub struct Normalized(Typed);
-
-impl Parsed {
- pub fn parse_file(f: &Path) -> Result<Parsed, Error> {
- parse::parse_file(f)
- }
- pub fn parse_str(s: &str) -> Result<Parsed, Error> {
- parse::parse_str(s)
- }
- pub fn parse_binary_file(f: &Path) -> Result<Parsed, Error> {
- parse::parse_binary_file(f)
- }
- pub fn parse_binary(data: &[u8]) -> Result<Parsed, Error> {
- parse::parse_binary(data)
- }
-
- pub fn resolve(self) -> Result<Resolved, ImportError> {
- resolve::resolve(self)
- }
- pub fn skip_resolve(self) -> Result<Resolved, ImportError> {
- resolve::skip_resolve_expr(self)
- }
-
- pub fn encode(&self) -> Result<Vec<u8>, EncodeError> {
- binary::encode(&self.0)
- }
-
- /// Converts a value back to the corresponding AST expression.
- pub fn to_expr(&self) -> ParsedExpr {
- self.0.clone()
- }
-}
-
-impl Resolved {
- pub fn typecheck(self) -> Result<Typed, TypeError> {
- Ok(typecheck::typecheck(self.0)?.into_typed())
- }
- pub fn typecheck_with(self, ty: &Typed) -> Result<Typed, TypeError> {
- Ok(typecheck::typecheck_with(self.0, ty.normalize_to_expr())?
- .into_typed())
- }
- /// Converts a value back to the corresponding AST expression.
- pub fn to_expr(&self) -> ResolvedExpr {
- self.0.clone()
- }
-}
-
-impl Typed {
- /// Reduce an expression to its normal form, performing beta reduction
- pub fn normalize(mut self) -> Normalized {
- self.normalize_mut();
- Normalized(self)
- }
-
- pub(crate) fn from_const(c: Const) -> Self {
- Typed(Value::from_const(c))
- }
- pub(crate) fn from_kind_and_type(v: ValueKind, t: Typed) -> Self {
- Typed(Value::from_kind_and_type(v, t.into_value()))
- }
- pub(crate) fn from_value(th: Value) -> Self {
- Typed(th)
- }
- pub(crate) fn const_type() -> Self {
- Typed::from_const(Const::Type)
- }
-
- /// Converts a value back to the corresponding AST expression.
- pub fn to_expr(&self) -> ResolvedExpr {
- self.0.to_expr(ToExprOptions {
- alpha: false,
- normalize: false,
- })
- }
- /// Converts a value back to the corresponding AST expression, beta-normalizing in the process.
- pub fn normalize_to_expr(&self) -> NormalizedExpr {
- self.0.to_expr(ToExprOptions {
- alpha: false,
- normalize: true,
- })
- }
- /// Converts a value back to the corresponding AST expression, (alpha,beta)-normalizing in the
- /// process.
- pub(crate) fn normalize_to_expr_alpha(&self) -> NormalizedExpr {
- self.0.to_expr(ToExprOptions {
- alpha: true,
- normalize: true,
- })
- }
- pub(crate) fn to_value(&self) -> Value {
- self.0.clone()
- }
- pub(crate) fn into_value(self) -> Value {
- self.0
- }
-
- pub(crate) fn normalize_mut(&mut self) {
- self.0.normalize_mut()
- }
-
- pub(crate) fn get_type(&self) -> Result<Typed, TypeError> {
- Ok(self.0.get_type()?.into_typed())
- }
-
- pub fn make_builtin_type(b: Builtin) -> Self {
- Typed::from_value(Value::from_builtin(b))
- }
- pub fn make_optional_type(t: Typed) -> Self {
- Typed::from_value(
- Value::from_builtin(Builtin::Optional).app(t.to_value()),
- )
- }
- pub fn make_list_type(t: Typed) -> Self {
- Typed::from_value(Value::from_builtin(Builtin::List).app(t.to_value()))
- }
- pub fn make_record_type(
- kts: impl Iterator<Item = (String, Typed)>,
- ) -> Self {
- Typed::from_kind_and_type(
- ValueKind::RecordType(
- kts.map(|(k, t)| (k.into(), t.into_value())).collect(),
- ),
- Typed::const_type(),
- )
- }
- pub fn make_union_type(
- kts: impl Iterator<Item = (String, Option<Typed>)>,
- ) -> Self {
- Typed::from_kind_and_type(
- ValueKind::UnionType(
- kts.map(|(k, t)| (k.into(), t.map(|t| t.into_value())))
- .collect(),
- ),
- Typed::const_type(),
- )
- }
-}
-
-impl Normalized {
- pub fn encode(&self) -> Result<Vec<u8>, EncodeError> {
- binary::encode(&self.to_expr())
- }
-
- pub(crate) fn to_expr(&self) -> NormalizedExpr {
- self.0.normalize_to_expr()
- }
- pub(crate) fn to_expr_alpha(&self) -> NormalizedExpr {
- self.0.normalize_to_expr_alpha()
- }
- pub(crate) fn into_typed(self) -> Typed {
- self.0
- }
-}
-
-impl Shift for Typed {
- fn shift(&self, delta: isize, var: &AlphaVar) -> Option<Self> {
- Some(Typed(self.0.shift(delta, var)?))
- }
-}
-
-impl Shift for Normalized {
- fn shift(&self, delta: isize, var: &AlphaVar) -> Option<Self> {
- Some(Normalized(self.0.shift(delta, var)?))
- }
-}
-
-impl Subst<Value> for Typed {
- fn subst_shift(&self, var: &AlphaVar, val: &Value) -> Self {
- Typed(self.0.subst_shift(var, val))
- }
-}
-
-macro_rules! derive_traits_for_wrapper_struct {
- ($ty:ident) => {
- impl std::cmp::PartialEq for $ty {
- fn eq(&self, other: &Self) -> bool {
- self.0 == other.0
- }
- }
-
- impl std::cmp::Eq for $ty {}
-
- impl std::fmt::Display for $ty {
- fn fmt(
- &self,
- f: &mut std::fmt::Formatter,
- ) -> Result<(), std::fmt::Error> {
- self.0.fmt(f)
- }
- }
- };
-}
-
-derive_traits_for_wrapper_struct!(Parsed);
-derive_traits_for_wrapper_struct!(Resolved);
-derive_traits_for_wrapper_struct!(Normalized);
-
-impl std::hash::Hash for Normalized {
- fn hash<H>(&self, state: &mut H)
- where
- H: std::hash::Hasher,
- {
- if let Ok(vec) = self.encode() {
- vec.hash(state)
- }
- }
-}
-
-impl Eq for Typed {}
-impl PartialEq for Typed {
- fn eq(&self, other: &Self) -> bool {
- self.0 == other.0
- }
-}
-
-impl Display for Typed {
- fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
- self.to_expr().fmt(f)
- }
-}
diff --git a/dhall/src/semantics/phase/normalize.rs b/dhall/src/semantics/phase/normalize.rs
deleted file mode 100644
index bf0c626..0000000
--- a/dhall/src/semantics/phase/normalize.rs
+++ /dev/null
@@ -1,791 +0,0 @@
-use std::collections::HashMap;
-use std::convert::TryInto;
-
-use crate::semantics::core::value::Value;
-use crate::semantics::core::value::ValueKind;
-use crate::semantics::core::var::{AlphaLabel, AlphaVar, Shift, Subst};
-use crate::semantics::phase::Normalized;
-use crate::syntax;
-use crate::syntax::Const::Type;
-use crate::syntax::{
- BinOp, Builtin, ExprKind, InterpolatedText, InterpolatedTextContents,
- Label, NaiveDouble,
-};
-
-// Ad-hoc macro to help construct closures
-macro_rules! make_closure {
- (#$var:ident) => { $var.clone() };
- (var($var:ident, $n:expr, $($ty:tt)*)) => {{
- let var = AlphaVar::from_var_and_alpha(
- Label::from(stringify!($var)).into(),
- $n
- );
- ValueKind::Var(var)
- .into_value_with_type(make_closure!($($ty)*))
- }};
- // Warning: assumes that $ty, as a dhall value, has type `Type`
- (λ($var:tt : $($ty:tt)*) -> $($body:tt)*) => {{
- let var: AlphaLabel = Label::from(stringify!($var)).into();
- let ty = make_closure!($($ty)*);
- let body = make_closure!($($body)*);
- let body_ty = body.get_type_not_sort();
- let lam_ty = ValueKind::Pi(var.clone(), ty.clone(), body_ty)
- .into_value_with_type(Value::from_const(Type));
- ValueKind::Lam(var, ty, body).into_value_with_type(lam_ty)
- }};
- (Natural) => {
- Value::from_builtin(Builtin::Natural)
- };
- (List $($rest:tt)*) => {
- Value::from_builtin(Builtin::List)
- .app(make_closure!($($rest)*))
- };
- (Some($($rest:tt)*)) => {{
- let v = make_closure!($($rest)*);
- let v_type = v.get_type_not_sort();
- let opt_v_type = Value::from_builtin(Builtin::Optional).app(v_type);
- ValueKind::NEOptionalLit(v).into_value_with_type(opt_v_type)
- }};
- (1 + $($rest:tt)*) => {
- ValueKind::PartialExpr(ExprKind::BinOp(
- syntax::BinOp::NaturalPlus,
- make_closure!($($rest)*),
- Value::from_kind_and_type(
- ValueKind::NaturalLit(1),
- make_closure!(Natural)
- ),
- )).into_value_with_type(
- make_closure!(Natural)
- )
- };
- ([ $($head:tt)* ] # $($tail:tt)*) => {{
- let head = make_closure!($($head)*);
- let tail = make_closure!($($tail)*);
- let list_type = tail.get_type_not_sort();
- ValueKind::PartialExpr(ExprKind::BinOp(
- syntax::BinOp::ListAppend,
- ValueKind::NEListLit(vec![head])
- .into_value_with_type(list_type.clone()),
- tail,
- )).into_value_with_type(list_type)
- }};
-}
-
-#[allow(clippy::cognitive_complexity)]
-pub(crate) fn apply_builtin(
- b: Builtin,
- args: Vec<Value>,
- ty: &Value,
-) -> ValueKind {
- use syntax::Builtin::*;
- use ValueKind::*;
-
- // Small helper enum
- enum Ret<'a> {
- ValueKind(ValueKind),
- Value(Value),
- // For applications that can return a function, it's important to keep the remaining
- // arguments to apply them to the resulting function.
- ValueWithRemainingArgs(&'a [Value], Value),
- DoneAsIs,
- }
-
- let ret = match (b, args.as_slice()) {
- (OptionalNone, [t]) => Ret::ValueKind(EmptyOptionalLit(t.clone())),
- (NaturalIsZero, [n]) => match &*n.as_whnf() {
- NaturalLit(n) => Ret::ValueKind(BoolLit(*n == 0)),
- _ => Ret::DoneAsIs,
- },
- (NaturalEven, [n]) => match &*n.as_whnf() {
- NaturalLit(n) => Ret::ValueKind(BoolLit(*n % 2 == 0)),
- _ => Ret::DoneAsIs,
- },
- (NaturalOdd, [n]) => match &*n.as_whnf() {
- NaturalLit(n) => Ret::ValueKind(BoolLit(*n % 2 != 0)),
- _ => Ret::DoneAsIs,
- },
- (NaturalToInteger, [n]) => match &*n.as_whnf() {
- NaturalLit(n) => Ret::ValueKind(IntegerLit(*n as isize)),
- _ => Ret::DoneAsIs,
- },
- (NaturalShow, [n]) => {
- match &*n.as_whnf() {
- NaturalLit(n) => Ret::ValueKind(TextLit(vec![
- InterpolatedTextContents::Text(n.to_string()),
- ])),
- _ => Ret::DoneAsIs,
- }
- }
- (NaturalSubtract, [a, b]) => match (&*a.as_whnf(), &*b.as_whnf()) {
- (NaturalLit(a), NaturalLit(b)) => {
- Ret::ValueKind(NaturalLit(if b > a { b - a } else { 0 }))
- }
- (NaturalLit(0), _) => Ret::Value(b.clone()),
- (_, NaturalLit(0)) => Ret::ValueKind(NaturalLit(0)),
- _ if a == b => Ret::ValueKind(NaturalLit(0)),
- _ => Ret::DoneAsIs,
- },
- (IntegerShow, [n]) => match &*n.as_whnf() {
- IntegerLit(n) => {
- let s = if *n < 0 {
- n.to_string()
- } else {
- format!("+{}", n)
- };
- Ret::ValueKind(TextLit(vec![InterpolatedTextContents::Text(s)]))
- }
- _ => Ret::DoneAsIs,
- },
- (IntegerToDouble, [n]) => match &*n.as_whnf() {
- IntegerLit(n) => {
- Ret::ValueKind(DoubleLit(NaiveDouble::from(*n as f64)))
- }
- _ => Ret::DoneAsIs,
- },
- (IntegerNegate, [n]) => match &*n.as_whnf() {
- IntegerLit(n) => Ret::ValueKind(IntegerLit(-n)),
- _ => Ret::DoneAsIs,
- },
- (IntegerClamp, [n]) => match &*n.as_whnf() {
- IntegerLit(n) => {
- Ret::ValueKind(NaturalLit((*n).try_into().unwrap_or(0)))
- }
- _ => Ret::DoneAsIs,
- },
- (DoubleShow, [n]) => {
- match &*n.as_whnf() {
- DoubleLit(n) => Ret::ValueKind(TextLit(vec![
- InterpolatedTextContents::Text(n.to_string()),
- ])),
- _ => Ret::DoneAsIs,
- }
- }
- (TextShow, [v]) => match &*v.as_whnf() {
- TextLit(elts) => {
- match elts.as_slice() {
- // Empty string literal.
- [] => {
- // Printing InterpolatedText takes care of all the escaping
- let txt: InterpolatedText<Normalized> =
- std::iter::empty().collect();
- let s = txt.to_string();
- Ret::ValueKind(TextLit(vec![
- InterpolatedTextContents::Text(s),
- ]))
- }
- // If there are no interpolations (invariants ensure that when there are no
- // interpolations, there is a single Text item) in the literal.
- [InterpolatedTextContents::Text(s)] => {
- // Printing InterpolatedText takes care of all the escaping
- let txt: InterpolatedText<Normalized> =
- std::iter::once(InterpolatedTextContents::Text(
- s.clone(),
- ))
- .collect();
- let s = txt.to_string();
- Ret::ValueKind(TextLit(vec![
- InterpolatedTextContents::Text(s),
- ]))
- }
- _ => Ret::DoneAsIs,
- }
- }
- _ => Ret::DoneAsIs,
- },
- (ListLength, [_, l]) => match &*l.as_whnf() {
- EmptyListLit(_) => Ret::ValueKind(NaturalLit(0)),
- NEListLit(xs) => Ret::ValueKind(NaturalLit(xs.len())),
- _ => Ret::DoneAsIs,
- },
- (ListHead, [_, l]) => match &*l.as_whnf() {
- EmptyListLit(n) => Ret::ValueKind(EmptyOptionalLit(n.clone())),
- NEListLit(xs) => {
- Ret::ValueKind(NEOptionalLit(xs.iter().next().unwrap().clone()))
- }
- _ => Ret::DoneAsIs,
- },
- (ListLast, [_, l]) => match &*l.as_whnf() {
- EmptyListLit(n) => Ret::ValueKind(EmptyOptionalLit(n.clone())),
- NEListLit(xs) => Ret::ValueKind(NEOptionalLit(
- xs.iter().rev().next().unwrap().clone(),
- )),
- _ => Ret::DoneAsIs,
- },
- (ListReverse, [_, l]) => match &*l.as_whnf() {
- EmptyListLit(n) => Ret::ValueKind(EmptyListLit(n.clone())),
- NEListLit(xs) => {
- Ret::ValueKind(NEListLit(xs.iter().rev().cloned().collect()))
- }
- _ => Ret::DoneAsIs,
- },
- (ListIndexed, [_, l]) => {
- let l_whnf = l.as_whnf();
- match &*l_whnf {
- EmptyListLit(_) | NEListLit(_) => {
- // Extract the type of the list elements
- let t = match &*l_whnf {
- EmptyListLit(t) => t.clone(),
- NEListLit(xs) => xs[0].get_type_not_sort(),
- _ => unreachable!(),
- };
-
- // Construct the returned record type: { index: Natural, value: t }
- let mut kts = HashMap::new();
- kts.insert("index".into(), Value::from_builtin(Natural));
- kts.insert("value".into(), t.clone());
- let t = Value::from_kind_and_type(
- RecordType(kts),
- Value::from_const(Type),
- );
-
- // Construct the new list, with added indices
- let list = match &*l_whnf {
- EmptyListLit(_) => EmptyListLit(t),
- NEListLit(xs) => NEListLit(
- xs.iter()
- .enumerate()
- .map(|(i, e)| {
- let mut kvs = HashMap::new();
- kvs.insert(
- "index".into(),
- Value::from_kind_and_type(
- NaturalLit(i),
- Value::from_builtin(
- Builtin::Natural,
- ),
- ),
- );
- kvs.insert("value".into(), e.clone());
- Value::from_kind_and_type(
- RecordLit(kvs),
- t.clone(),
- )
- })
- .collect(),
- ),
- _ => unreachable!(),
- };
- Ret::ValueKind(list)
- }
- _ => Ret::DoneAsIs,
- }
- }
- (ListBuild, [t, f]) => {
- let list_t = Value::from_builtin(List).app(t.clone());
- Ret::Value(
- f.app(list_t.clone())
- .app({
- // Move `t` under new variables
- let t1 = t.under_binder(Label::from("a"));
- let t2 = t1.under_binder(Label::from("as"));
- make_closure!(
- λ(a : #t) ->
- λ(as : List #t1) ->
- [ var(a, 1, #t2) ] # var(as, 0, List #t2)
- )
- })
- .app(EmptyListLit(t.clone()).into_value_with_type(list_t)),
- )
- }
- (ListFold, [_, l, _, cons, nil, r @ ..]) => match &*l.as_whnf() {
- EmptyListLit(_) => Ret::ValueWithRemainingArgs(r, nil.clone()),
- NEListLit(xs) => {
- let mut v = nil.clone();
- for x in xs.iter().cloned().rev() {
- v = cons.app(x).app(v);
- }
- Ret::ValueWithRemainingArgs(r, v)
- }
- _ => Ret::DoneAsIs,
- },
- (OptionalBuild, [t, f]) => {
- let optional_t = Value::from_builtin(Optional).app(t.clone());
- Ret::Value(
- f.app(optional_t.clone())
- .app({
- let t1 = t.under_binder(Label::from("a"));
- make_closure!(λ(a: #t) -> Some(var(a, 0, #t1)))
- })
- .app(
- EmptyOptionalLit(t.clone())
- .into_value_with_type(optional_t),
- ),
- )
- }
- (OptionalFold, [_, v, _, just, nothing, r @ ..]) => match &*v.as_whnf()
- {
- EmptyOptionalLit(_) => {
- Ret::ValueWithRemainingArgs(r, nothing.clone())
- }
- NEOptionalLit(x) => {
- Ret::ValueWithRemainingArgs(r, just.app(x.clone()))
- }
- _ => Ret::DoneAsIs,
- },
- (NaturalBuild, [f]) => Ret::Value(
- f.app(Value::from_builtin(Natural))
- .app(make_closure!(
- λ(x : Natural) -> 1 + var(x, 0, Natural)
- ))
- .app(
- NaturalLit(0)
- .into_value_with_type(Value::from_builtin(Natural)),
- ),
- ),
-
- (NaturalFold, [n, t, succ, zero, r @ ..]) => match &*n.as_whnf() {
- NaturalLit(0) => Ret::ValueWithRemainingArgs(r, zero.clone()),
- NaturalLit(n) => {
- let fold = Value::from_builtin(NaturalFold)
- .app(
- NaturalLit(n - 1)
- .into_value_with_type(Value::from_builtin(Natural)),
- )
- .app(t.clone())
- .app(succ.clone())
- .app(zero.clone());
- Ret::ValueWithRemainingArgs(r, succ.app(fold))
- }
- _ => Ret::DoneAsIs,
- },
- _ => Ret::DoneAsIs,
- };
- match ret {
- Ret::ValueKind(v) => v,
- Ret::Value(v) => v.to_whnf_check_type(ty),
- Ret::ValueWithRemainingArgs(unconsumed_args, mut v) => {
- let n_consumed_args = args.len() - unconsumed_args.len();
- for x in args.into_iter().skip(n_consumed_args) {
- v = v.app(x);
- }
- v.to_whnf_check_type(ty)
- }
- Ret::DoneAsIs => AppliedBuiltin(b, args),
- }
-}
-
-pub(crate) fn apply_any(f: Value, a: Value, ty: &Value) -> ValueKind {
- let f_borrow = f.as_whnf();
- match &*f_borrow {
- ValueKind::Lam(x, _, e) => {
- e.subst_shift(&x.into(), &a).to_whnf_check_type(ty)
- }
- ValueKind::AppliedBuiltin(b, args) => {
- use std::iter::once;
- let args = args.iter().cloned().chain(once(a.clone())).collect();
- apply_builtin(*b, args, ty)
- }
- ValueKind::UnionConstructor(l, kts) => {
- ValueKind::UnionLit(l.clone(), a, kts.clone())
- }
- _ => {
- drop(f_borrow);
- ValueKind::PartialExpr(ExprKind::App(f, a))
- }
- }
-}
-
-pub(crate) fn squash_textlit(
- elts: impl Iterator<Item = InterpolatedTextContents<Value>>,
-) -> Vec<InterpolatedTextContents<Value>> {
- use std::mem::replace;
- use InterpolatedTextContents::{Expr, Text};
-
- fn inner(
- elts: impl Iterator<Item = InterpolatedTextContents<Value>>,
- crnt_str: &mut String,
- ret: &mut Vec<InterpolatedTextContents<Value>>,
- ) {
- for contents in elts {
- match contents {
- Text(s) => crnt_str.push_str(&s),
- Expr(e) => {
- let e_borrow = e.as_whnf();
- match &*e_borrow {
- ValueKind::TextLit(elts2) => {
- inner(elts2.iter().cloned(), crnt_str, ret)
- }
- _ => {
- drop(e_borrow);
- if !crnt_str.is_empty() {
- ret.push(Text(replace(crnt_str, String::new())))
- }
- ret.push(Expr(e.clone()))
- }
- }
- }
- }
- }
- }
-
- let mut crnt_str = String::new();
- let mut ret = Vec::new();
- inner(elts, &mut crnt_str, &mut ret);
- if !crnt_str.is_empty() {
- ret.push(Text(replace(&mut crnt_str, String::new())))
- }
- ret
-}
-
-pub(crate) fn merge_maps<K, V, F, Err>(
- map1: &HashMap<K, V>,
- map2: &HashMap<K, V>,
- mut f: F,
-) -> Result<HashMap<K, V>, Err>
-where
- F: FnMut(&K, &V, &V) -> Result<V, Err>,
- K: std::hash::Hash + Eq + Clone,
- V: Clone,
-{
- let mut kvs = HashMap::new();
- for (x, v2) in map2 {
- let newv = if let Some(v1) = map1.get(x) {
- f(x, v1, v2)?
- } else {
- v2.clone()
- };
- kvs.insert(x.clone(), newv);
- }
- for (x, v1) in map1 {
- // Insert only if key not already present
- kvs.entry(x.clone()).or_insert_with(|| v1.clone());
- }
- Ok(kvs)
-}
-
-// Small helper enum to avoid repetition
-enum Ret<'a> {
- ValueKind(ValueKind),
- Value(Value),
- ValueRef(&'a Value),
- Expr(ExprKind<Value, Normalized>),
-}
-
-fn apply_binop<'a>(
- o: BinOp,
- x: &'a Value,
- y: &'a Value,
- ty: &Value,
-) -> Option<Ret<'a>> {
- use BinOp::{
- BoolAnd, BoolEQ, BoolNE, BoolOr, Equivalence, ListAppend, NaturalPlus,
- NaturalTimes, RecursiveRecordMerge, RecursiveRecordTypeMerge,
- RightBiasedRecordMerge, TextAppend,
- };
- use ValueKind::{
- BoolLit, EmptyListLit, NEListLit, NaturalLit, RecordLit, RecordType,
- TextLit,
- };
- let x_borrow = x.as_whnf();
- let y_borrow = y.as_whnf();
- Some(match (o, &*x_borrow, &*y_borrow) {
- (BoolAnd, BoolLit(true), _) => Ret::ValueRef(y),
- (BoolAnd, _, BoolLit(true)) => Ret::ValueRef(x),
- (BoolAnd, BoolLit(false), _) => Ret::ValueKind(BoolLit(false)),
- (BoolAnd, _, BoolLit(false)) => Ret::ValueKind(BoolLit(false)),
- (BoolAnd, _, _) if x == y => Ret::ValueRef(x),
- (BoolOr, BoolLit(true), _) => Ret::ValueKind(BoolLit(true)),
- (BoolOr, _, BoolLit(true)) => Ret::ValueKind(BoolLit(true)),
- (BoolOr, BoolLit(false), _) => Ret::ValueRef(y),
- (BoolOr, _, BoolLit(false)) => Ret::ValueRef(x),
- (BoolOr, _, _) if x == y => Ret::ValueRef(x),
- (BoolEQ, BoolLit(true), _) => Ret::ValueRef(y),
- (BoolEQ, _, BoolLit(true)) => Ret::ValueRef(x),
- (BoolEQ, BoolLit(x), BoolLit(y)) => Ret::ValueKind(BoolLit(x == y)),
- (BoolEQ, _, _) if x == y => Ret::ValueKind(BoolLit(true)),
- (BoolNE, BoolLit(false), _) => Ret::ValueRef(y),
- (BoolNE, _, BoolLit(false)) => Ret::ValueRef(x),
- (BoolNE, BoolLit(x), BoolLit(y)) => Ret::ValueKind(BoolLit(x != y)),
- (BoolNE, _, _) if x == y => Ret::ValueKind(BoolLit(false)),
-
- (NaturalPlus, NaturalLit(0), _) => Ret::ValueRef(y),
- (NaturalPlus, _, NaturalLit(0)) => Ret::ValueRef(x),
- (NaturalPlus, NaturalLit(x), NaturalLit(y)) => {
- Ret::ValueKind(NaturalLit(x + y))
- }
- (NaturalTimes, NaturalLit(0), _) => Ret::ValueKind(NaturalLit(0)),
- (NaturalTimes, _, NaturalLit(0)) => Ret::ValueKind(NaturalLit(0)),
- (NaturalTimes, NaturalLit(1), _) => Ret::ValueRef(y),
- (NaturalTimes, _, NaturalLit(1)) => Ret::ValueRef(x),
- (NaturalTimes, NaturalLit(x), NaturalLit(y)) => {
- Ret::ValueKind(NaturalLit(x * y))
- }
-
- (ListAppend, EmptyListLit(_), _) => Ret::ValueRef(y),
- (ListAppend, _, EmptyListLit(_)) => Ret::ValueRef(x),
- (ListAppend, NEListLit(xs), NEListLit(ys)) => Ret::ValueKind(
- NEListLit(xs.iter().chain(ys.iter()).cloned().collect()),
- ),
-
- (TextAppend, TextLit(x), _) if x.is_empty() => Ret::ValueRef(y),
- (TextAppend, _, TextLit(y)) if y.is_empty() => Ret::ValueRef(x),
- (TextAppend, TextLit(x), TextLit(y)) => Ret::ValueKind(TextLit(
- squash_textlit(x.iter().chain(y.iter()).cloned()),
- )),
- (TextAppend, TextLit(x), _) => {
- use std::iter::once;
- let y = InterpolatedTextContents::Expr(y.clone());
- Ret::ValueKind(TextLit(squash_textlit(
- x.iter().cloned().chain(once(y)),
- )))
- }
- (TextAppend, _, TextLit(y)) => {
- use std::iter::once;
- let x = InterpolatedTextContents::Expr(x.clone());
- Ret::ValueKind(TextLit(squash_textlit(
- once(x).chain(y.iter().cloned()),
- )))
- }
-
- (RightBiasedRecordMerge, _, RecordLit(kvs)) if kvs.is_empty() => {
- Ret::ValueRef(x)
- }
- (RightBiasedRecordMerge, RecordLit(kvs), _) if kvs.is_empty() => {
- Ret::ValueRef(y)
- }
- (RightBiasedRecordMerge, RecordLit(kvs1), RecordLit(kvs2)) => {
- let mut kvs = kvs2.clone();
- for (x, v) in kvs1 {
- // Insert only if key not already present
- kvs.entry(x.clone()).or_insert_with(|| v.clone());
- }
- Ret::ValueKind(RecordLit(kvs))
- }
-
- (RecursiveRecordMerge, _, RecordLit(kvs)) if kvs.is_empty() => {
- Ret::ValueRef(x)
- }
- (RecursiveRecordMerge, RecordLit(kvs), _) if kvs.is_empty() => {
- Ret::ValueRef(y)
- }
- (RecursiveRecordMerge, RecordLit(kvs1), RecordLit(kvs2)) => {
- let ty_borrow = ty.as_whnf();
- let kts = match &*ty_borrow {
- RecordType(kts) => kts,
- _ => unreachable!("Internal type error"),
- };
- let kvs = merge_maps::<_, _, _, !>(kvs1, kvs2, |k, v1, v2| {
- Ok(Value::from_kind_and_type(
- ValueKind::PartialExpr(ExprKind::BinOp(
- RecursiveRecordMerge,
- v1.clone(),
- v2.clone(),
- )),
- kts.get(k).expect("Internal type error").clone(),
- ))
- })?;
- Ret::ValueKind(RecordLit(kvs))
- }
-
- (RecursiveRecordTypeMerge, _, _) | (Equivalence, _, _) => {
- unreachable!("This case should have been handled in typecheck")
- }
-
- _ => return None,
- })
-}
-
-pub(crate) fn normalize_one_layer(
- expr: ExprKind<Value, Normalized>,
- ty: &Value,
-) -> ValueKind {
- use ValueKind::{
- AppliedBuiltin, BoolLit, DoubleLit, EmptyListLit, EmptyOptionalLit,
- IntegerLit, NEListLit, NEOptionalLit, NaturalLit, RecordLit, TextLit,
- UnionConstructor, UnionLit, UnionType,
- };
-
- let ret = match expr {
- ExprKind::Import(_) => unreachable!(
- "There should remain no imports in a resolved expression"
- ),
- // Those cases have already been completely handled in the typechecking phase (using
- // `RetWhole`), so they won't appear here.
- ExprKind::Lam(_, _, _)
- | ExprKind::Pi(_, _, _)
- | ExprKind::Let(_, _, _, _)
- | ExprKind::Embed(_)
- | ExprKind::Const(_)
- | ExprKind::Builtin(_)
- | ExprKind::Var(_)
- | ExprKind::Annot(_, _)
- | ExprKind::RecordType(_)
- | ExprKind::UnionType(_) => {
- unreachable!("This case should have been handled in typecheck")
- }
- ExprKind::Assert(_) => Ret::Expr(expr),
- ExprKind::App(v, a) => Ret::Value(v.app(a)),
- ExprKind::BoolLit(b) => Ret::ValueKind(BoolLit(b)),
- ExprKind::NaturalLit(n) => Ret::ValueKind(NaturalLit(n)),
- ExprKind::IntegerLit(n) => Ret::ValueKind(IntegerLit(n)),
- ExprKind::DoubleLit(n) => Ret::ValueKind(DoubleLit(n)),
- ExprKind::SomeLit(e) => Ret::ValueKind(NEOptionalLit(e)),
- ExprKind::EmptyListLit(ref t) => {
- // Check if the type is of the form `List x`
- let t_borrow = t.as_whnf();
- match &*t_borrow {
- AppliedBuiltin(Builtin::List, args) if args.len() == 1 => {
- Ret::ValueKind(EmptyListLit(args[0].clone()))
- }
- _ => {
- drop(t_borrow);
- Ret::Expr(expr)
- }
- }
- }
- ExprKind::NEListLit(elts) => {
- Ret::ValueKind(NEListLit(elts.into_iter().collect()))
- }
- ExprKind::RecordLit(kvs) => {
- Ret::ValueKind(RecordLit(kvs.into_iter().collect()))
- }
- ExprKind::TextLit(elts) => {
- use InterpolatedTextContents::Expr;
- let elts: Vec<_> = squash_textlit(elts.into_iter());
- // Simplify bare interpolation
- if let [Expr(th)] = elts.as_slice() {
- Ret::Value(th.clone())
- } else {
- Ret::ValueKind(TextLit(elts))
- }
- }
- ExprKind::BoolIf(ref b, ref e1, ref e2) => {
- let b_borrow = b.as_whnf();
- match &*b_borrow {
- BoolLit(true) => Ret::ValueRef(e1),
- BoolLit(false) => Ret::ValueRef(e2),
- _ => {
- let e1_borrow = e1.as_whnf();
- let e2_borrow = e2.as_whnf();
- match (&*e1_borrow, &*e2_borrow) {
- // Simplify `if b then True else False`
- (BoolLit(true), BoolLit(false)) => Ret::ValueRef(b),
- _ if e1 == e2 => Ret::ValueRef(e1),
- _ => {
- drop(b_borrow);
- drop(e1_borrow);
- drop(e2_borrow);
- Ret::Expr(expr)
- }
- }
- }
- }
- }
- ExprKind::BinOp(o, ref x, ref y) => match apply_binop(o, x, y, ty) {
- Some(ret) => ret,
- None => Ret::Expr(expr),
- },
-
- ExprKind::Projection(_, ref ls) if ls.is_empty() => {
- Ret::ValueKind(RecordLit(HashMap::new()))
- }
- ExprKind::Projection(ref v, ref ls) => {
- let v_borrow = v.as_whnf();
- match &*v_borrow {
- RecordLit(kvs) => Ret::ValueKind(RecordLit(
- ls.iter()
- .filter_map(|l| {
- kvs.get(l).map(|x| (l.clone(), x.clone()))
- })
- .collect(),
- )),
- _ => {
- drop(v_borrow);
- Ret::Expr(expr)
- }
- }
- }
- ExprKind::Field(ref v, ref l) => {
- let v_borrow = v.as_whnf();
- match &*v_borrow {
- RecordLit(kvs) => match kvs.get(l) {
- Some(r) => Ret::Value(r.clone()),
- None => {
- drop(v_borrow);
- Ret::Expr(expr)
- }
- },
- UnionType(kts) => {
- Ret::ValueKind(UnionConstructor(l.clone(), kts.clone()))
- }
- _ => {
- drop(v_borrow);
- Ret::Expr(expr)
- }
- }
- }
- ExprKind::ProjectionByExpr(_, _) => {
- unimplemented!("selection by expression")
- }
- ExprKind::Completion(_, _) => unimplemented!("record completion"),
-
- ExprKind::Merge(ref handlers, ref variant, _) => {
- let handlers_borrow = handlers.as_whnf();
- let variant_borrow = variant.as_whnf();
- match (&*handlers_borrow, &*variant_borrow) {
- (RecordLit(kvs), UnionConstructor(l, _)) => match kvs.get(l) {
- Some(h) => Ret::Value(h.clone()),
- None => {
- drop(handlers_borrow);
- drop(variant_borrow);
- Ret::Expr(expr)
- }
- },
- (RecordLit(kvs), UnionLit(l, v, _)) => match kvs.get(l) {
- Some(h) => Ret::Value(h.app(v.clone())),
- None => {
- drop(handlers_borrow);
- drop(variant_borrow);
- Ret::Expr(expr)
- }
- },
- (RecordLit(kvs), EmptyOptionalLit(_)) => {
- match kvs.get(&"None".into()) {
- Some(h) => Ret::Value(h.clone()),
- None => {
- drop(handlers_borrow);
- drop(variant_borrow);
- Ret::Expr(expr)
- }
- }
- }
- (RecordLit(kvs), NEOptionalLit(v)) => {
- match kvs.get(&"Some".into()) {
- Some(h) => Ret::Value(h.app(v.clone())),
- None => {
- drop(handlers_borrow);
- drop(variant_borrow);
- Ret::Expr(expr)
- }
- }
- }
- _ => {
- drop(handlers_borrow);
- drop(variant_borrow);
- Ret::Expr(expr)
- }
- }
- }
- ExprKind::ToMap(_, _) => unimplemented!("toMap"),
- };
-
- match ret {
- Ret::ValueKind(v) => v,
- Ret::Value(v) => v.to_whnf_check_type(ty),
- Ret::ValueRef(v) => v.to_whnf_check_type(ty),
- Ret::Expr(expr) => ValueKind::PartialExpr(expr),
- }
-}
-
-/// Normalize a ValueKind into WHNF
-pub(crate) fn normalize_whnf(v: ValueKind, ty: &Value) -> ValueKind {
- match v {
- ValueKind::AppliedBuiltin(b, args) => apply_builtin(b, args, ty),
- ValueKind::PartialExpr(e) => normalize_one_layer(e, ty),
- ValueKind::TextLit(elts) => {
- ValueKind::TextLit(squash_textlit(elts.into_iter()))
- }
- // All other cases are already in WHNF
- v => v,
- }
-}
diff --git a/dhall/src/semantics/phase/typecheck.rs b/dhall/src/semantics/phase/typecheck.rs
deleted file mode 100644
index 3960146..0000000
--- a/dhall/src/semantics/phase/typecheck.rs
+++ /dev/null
@@ -1,838 +0,0 @@
-use std::borrow::Cow;
-use std::cmp::max;
-use std::collections::HashMap;
-
-use crate::error::{TypeError, TypeMessage};
-use crate::semantics::core::context::TypecheckContext;
-use crate::semantics::core::value::Value;
-use crate::semantics::core::value::ValueKind;
-use crate::semantics::core::var::{Shift, Subst};
-use crate::semantics::phase::normalize::merge_maps;
-use crate::semantics::phase::Normalized;
-use crate::syntax;
-use crate::syntax::{
- Builtin, Const, Expr, ExprKind, InterpolatedTextContents, Label, Span,
- UnspannedExpr,
-};
-
-fn tck_pi_type(
- ctx: &TypecheckContext,
- x: Label,
- tx: Value,
- te: Value,
-) -> Result<Value, TypeError> {
- use TypeMessage::*;
- let ctx2 = ctx.insert_type(&x, tx.clone());
-
- let ka = match tx.get_type()?.as_const() {
- Some(k) => k,
- _ => return Err(TypeError::new(ctx, InvalidInputType(tx))),
- };
-
- let kb = match te.get_type()?.as_const() {
- Some(k) => k,
- _ => {
- return Err(TypeError::new(
- &ctx2,
- InvalidOutputType(te.get_type()?),
- ))
- }
- };
-
- let k = function_check(ka, kb);
-
- Ok(Value::from_kind_and_type(
- ValueKind::Pi(x.into(), tx, te),
- Value::from_const(k),
- ))
-}
-
-fn tck_record_type(
- ctx: &TypecheckContext,
- kts: impl IntoIterator<Item = Result<(Label, Value), TypeError>>,
-) -> Result<Value, TypeError> {
- use std::collections::hash_map::Entry;
- use TypeMessage::*;
- let mut new_kts = HashMap::new();
- // An empty record type has type Type
- let mut k = Const::Type;
- for e in kts {
- let (x, t) = e?;
- // Construct the union of the contained `Const`s
- match t.get_type()?.as_const() {
- Some(k2) => k = max(k, k2),
- None => return Err(TypeError::new(ctx, InvalidFieldType(x, t))),
- }
- // Check for duplicated entries
- let entry = new_kts.entry(x);
- match &entry {
- Entry::Occupied(_) => {
- return Err(TypeError::new(ctx, RecordTypeDuplicateField))
- }
- Entry::Vacant(_) => entry.or_insert_with(|| t),
- };
- }
-
- Ok(Value::from_kind_and_type(
- ValueKind::RecordType(new_kts),
- Value::from_const(k),
- ))
-}
-
-fn tck_union_type<Iter>(
- ctx: &TypecheckContext,
- kts: Iter,
-) -> Result<Value, TypeError>
-where
- Iter: IntoIterator<Item = Result<(Label, Option<Value>), TypeError>>,
-{
- use std::collections::hash_map::Entry;
- use TypeMessage::*;
- let mut new_kts = HashMap::new();
- // Check that all types are the same const
- let mut k = None;
- for e in kts {
- let (x, t) = e?;
- 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(TypeError::new(
- ctx,
- InvalidFieldType(x, t.clone()),
- ))
- }
- }
- }
- let entry = new_kts.entry(x);
- match &entry {
- Entry::Occupied(_) => {
- return Err(TypeError::new(ctx, UnionTypeDuplicateField))
- }
- Entry::Vacant(_) => entry.or_insert_with(|| t),
- };
- }
-
- // An empty union type has type Type;
- // an union type with only unary variants also has type Type
- let k = k.unwrap_or(Const::Type);
-
- Ok(Value::from_kind_and_type(
- ValueKind::UnionType(new_kts),
- Value::from_const(k),
- ))
-}
-
-fn function_check(a: Const, b: Const) -> Const {
- if b == Const::Type {
- Const::Type
- } else {
- max(a, b)
- }
-}
-
-pub(crate) fn const_to_value(c: Const) -> Value {
- let v = ValueKind::Const(c);
- match c {
- Const::Type => {
- Value::from_kind_and_type(v, const_to_value(Const::Kind))
- }
- Const::Kind => {
- Value::from_kind_and_type(v, const_to_value(Const::Sort))
- }
- Const::Sort => Value::const_sort(),
- }
-}
-
-pub fn rc<E>(x: UnspannedExpr<E>) -> Expr<E> {
- Expr::new(x, Span::Artificial)
-}
-
-// Ad-hoc macro to help construct the types of builtins
-macro_rules! make_type {
- (Type) => { ExprKind::Const(Const::Type) };
- (Bool) => { ExprKind::Builtin(Builtin::Bool) };
- (Natural) => { ExprKind::Builtin(Builtin::Natural) };
- (Integer) => { ExprKind::Builtin(Builtin::Integer) };
- (Double) => { ExprKind::Builtin(Builtin::Double) };
- (Text) => { ExprKind::Builtin(Builtin::Text) };
- ($var:ident) => {
- ExprKind::Var(syntax::V(stringify!($var).into(), 0))
- };
- (Optional $ty:ident) => {
- ExprKind::App(
- rc(ExprKind::Builtin(Builtin::Optional)),
- rc(make_type!($ty))
- )
- };
- (List $($rest:tt)*) => {
- ExprKind::App(
- rc(ExprKind::Builtin(Builtin::List)),
- rc(make_type!($($rest)*))
- )
- };
- ({ $($label:ident : $ty:ident),* }) => {{
- let mut kts = syntax::map::DupTreeMap::new();
- $(
- kts.insert(
- Label::from(stringify!($label)),
- rc(make_type!($ty)),
- );
- )*
- ExprKind::RecordType(kts)
- }};
- ($ty:ident -> $($rest:tt)*) => {
- ExprKind::Pi(
- "_".into(),
- rc(make_type!($ty)),
- rc(make_type!($($rest)*))
- )
- };
- (($($arg:tt)*) -> $($rest:tt)*) => {
- ExprKind::Pi(
- "_".into(),
- rc(make_type!($($arg)*)),
- rc(make_type!($($rest)*))
- )
- };
- (forall ($var:ident : $($ty:tt)*) -> $($rest:tt)*) => {
- ExprKind::Pi(
- stringify!($var).into(),
- rc(make_type!($($ty)*)),
- rc(make_type!($($rest)*))
- )
- };
-}
-
-fn type_of_builtin<E>(b: Builtin) -> Expr<E> {
- use syntax::Builtin::*;
- rc(match b {
- Bool | Natural | Integer | Double | Text => make_type!(Type),
- List | Optional => make_type!(
- Type -> Type
- ),
-
- NaturalFold => make_type!(
- Natural ->
- forall (natural: Type) ->
- forall (succ: natural -> natural) ->
- forall (zero: natural) ->
- natural
- ),
- NaturalBuild => make_type!(
- (forall (natural: Type) ->
- forall (succ: natural -> natural) ->
- forall (zero: natural) ->
- natural) ->
- Natural
- ),
- NaturalIsZero | NaturalEven | NaturalOdd => make_type!(
- Natural -> Bool
- ),
- NaturalToInteger => make_type!(Natural -> Integer),
- NaturalShow => make_type!(Natural -> Text),
- NaturalSubtract => make_type!(Natural -> Natural -> Natural),
-
- IntegerToDouble => make_type!(Integer -> Double),
- IntegerShow => make_type!(Integer -> Text),
- IntegerNegate => make_type!(Integer -> Integer),
- IntegerClamp => make_type!(Integer -> Natural),
-
- DoubleShow => make_type!(Double -> Text),
- TextShow => make_type!(Text -> Text),
-
- ListBuild => make_type!(
- forall (a: Type) ->
- (forall (list: Type) ->
- forall (cons: a -> list -> list) ->
- forall (nil: list) ->
- list) ->
- List a
- ),
- ListFold => make_type!(
- forall (a: Type) ->
- (List a) ->
- forall (list: Type) ->
- forall (cons: a -> list -> list) ->
- forall (nil: list) ->
- list
- ),
- ListLength => make_type!(forall (a: Type) -> (List a) -> Natural),
- ListHead | ListLast => {
- make_type!(forall (a: Type) -> (List a) -> Optional a)
- }
- ListIndexed => make_type!(
- forall (a: Type) ->
- (List a) ->
- List { index: Natural, value: a }
- ),
- ListReverse => make_type!(
- forall (a: Type) -> (List a) -> List a
- ),
-
- OptionalBuild => make_type!(
- forall (a: Type) ->
- (forall (optional: Type) ->
- forall (just: a -> optional) ->
- forall (nothing: optional) ->
- optional) ->
- Optional a
- ),
- OptionalFold => make_type!(
- forall (a: Type) ->
- (Optional a) ->
- forall (optional: Type) ->
- forall (just: a -> optional) ->
- forall (nothing: optional) ->
- optional
- ),
- OptionalNone => make_type!(
- forall (A: Type) -> Optional A
- ),
- })
-}
-
-pub(crate) fn builtin_to_value(b: Builtin) -> Value {
- let ctx = TypecheckContext::new();
- Value::from_kind_and_type(
- ValueKind::from_builtin(b),
- type_with(&ctx, type_of_builtin(b)).unwrap(),
- )
-}
-
-/// Type-check an expression and return the expression alongside its type if type-checking
-/// succeeded, or an error if type-checking failed.
-/// Some normalization is done while typechecking, so the returned expression might be partially
-/// normalized as well.
-fn type_with(
- ctx: &TypecheckContext,
- e: Expr<Normalized>,
-) -> Result<Value, TypeError> {
- use syntax::ExprKind::{Annot, Embed, Lam, Let, Pi, Var};
- let span = e.span();
-
- Ok(match e.as_ref() {
- Lam(var, annot, body) => {
- let annot = type_with(ctx, annot.clone())?;
- annot.normalize_nf();
- let ctx2 = ctx.insert_type(var, annot.clone());
- let body = type_with(&ctx2, body.clone())?;
- let body_type = body.get_type()?;
- Value::from_kind_and_type(
- ValueKind::Lam(var.clone().into(), annot.clone(), body),
- tck_pi_type(ctx, var.clone(), annot, body_type)?,
- )
- }
- Pi(x, ta, tb) => {
- let ta = type_with(ctx, ta.clone())?;
- let ctx2 = ctx.insert_type(x, ta.clone());
- let tb = type_with(&ctx2, tb.clone())?;
- return tck_pi_type(ctx, x.clone(), ta, tb);
- }
- 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)?;
- return type_with(&ctx.insert_value(x, v.clone())?, e.clone());
- }
- Embed(p) => p.clone().into_typed().into_value(),
- Var(var) => match ctx.lookup(&var) {
- Some(typed) => typed.clone(),
- None => {
- return Err(TypeError::new(
- ctx,
- TypeMessage::UnboundVariable(span),
- ))
- }
- },
- e => {
- // Typecheck recursively all subexpressions
- let expr = e.traverse_ref_with_special_handling_of_binders(
- |e| type_with(ctx, e.clone()),
- |_, _| unreachable!(),
- )?;
- type_last_layer(ctx, expr, span)?
- }
- })
-}
-
-/// When all sub-expressions have been typed, check the remaining toplevel
-/// layer.
-fn type_last_layer(
- ctx: &TypecheckContext,
- e: ExprKind<Value, Normalized>,
- span: Span,
-) -> Result<Value, TypeError> {
- use syntax::BinOp::*;
- use syntax::Builtin::*;
- use syntax::Const::Type;
- use syntax::ExprKind::*;
- use TypeMessage::*;
- let mkerr = |msg: TypeMessage| Err(TypeError::new(ctx, msg));
-
- /// Intermediary return type
- enum Ret {
- /// Returns the contained value as is
- RetWhole(Value),
- /// Returns the input expression `e` with the contained value as its type
- RetTypeOnly(Value),
- }
- use Ret::*;
-
- let ret = match &e {
- Import(_) => unreachable!(
- "There should remain no imports in a resolved expression"
- ),
- Lam(_, _, _) | Pi(_, _, _) | Let(_, _, _, _) | Embed(_) | Var(_) => {
- unreachable!()
- }
- App(f, a) => {
- let tf = f.get_type()?;
- let tf_borrow = tf.as_whnf();
- let (x, tx, tb) = match &*tf_borrow {
- ValueKind::Pi(x, tx, tb) => (x, tx, tb),
- _ => return mkerr(NotAFunction(f.clone())),
- };
- if &a.get_type()? != tx {
- return mkerr(TypeMismatch(f.clone(), tx.clone(), a.clone()));
- }
-
- let ret = tb.subst_shift(&x.into(), a);
- ret.normalize_nf();
- RetTypeOnly(ret)
- }
- Annot(x, t) => {
- if &x.get_type()? != t {
- return mkerr(AnnotMismatch(x.clone(), t.clone()));
- }
- RetWhole(x.clone())
- }
- Assert(t) => {
- match &*t.as_whnf() {
- ValueKind::Equivalence(x, y) if x == y => {}
- ValueKind::Equivalence(x, y) => {
- return mkerr(AssertMismatch(x.clone(), y.clone()))
- }
- _ => return mkerr(AssertMustTakeEquivalence),
- }
- RetTypeOnly(t.clone())
- }
- BoolIf(x, y, z) => {
- if *x.get_type()?.as_whnf() != ValueKind::from_builtin(Bool) {
- return mkerr(InvalidPredicate(x.clone()));
- }
-
- if y.get_type()?.get_type()?.as_const() != Some(Type) {
- return mkerr(IfBranchMustBeTerm(true, y.clone()));
- }
-
- if z.get_type()?.get_type()?.as_const() != Some(Type) {
- return mkerr(IfBranchMustBeTerm(false, z.clone()));
- }
-
- if y.get_type()? != z.get_type()? {
- return mkerr(IfBranchMismatch(y.clone(), z.clone()));
- }
-
- RetTypeOnly(y.get_type()?)
- }
- EmptyListLit(t) => {
- match &*t.as_whnf() {
- ValueKind::AppliedBuiltin(syntax::Builtin::List, args)
- if args.len() == 1 => {}
- _ => return mkerr(InvalidListType(t.clone())),
- }
- RetTypeOnly(t.clone())
- }
- NEListLit(xs) => {
- let mut iter = xs.iter().enumerate();
- let (_, x) = iter.next().unwrap();
- for (i, y) in iter {
- if x.get_type()? != y.get_type()? {
- return mkerr(InvalidListElement(
- i,
- x.get_type()?,
- y.clone(),
- ));
- }
- }
- let t = x.get_type()?;
- if t.get_type()?.as_const() != Some(Type) {
- return mkerr(InvalidListType(t));
- }
-
- RetTypeOnly(Value::from_builtin(syntax::Builtin::List).app(t))
- }
- SomeLit(x) => {
- let t = x.get_type()?;
- if t.get_type()?.as_const() != Some(Type) {
- return mkerr(InvalidOptionalType(t));
- }
-
- RetTypeOnly(Value::from_builtin(syntax::Builtin::Optional).app(t))
- }
- RecordType(kts) => RetWhole(tck_record_type(
- ctx,
- kts.iter().map(|(x, t)| Ok((x.clone(), t.clone()))),
- )?),
- UnionType(kts) => RetWhole(tck_union_type(
- ctx,
- kts.iter().map(|(x, t)| Ok((x.clone(), t.clone()))),
- )?),
- RecordLit(kvs) => RetTypeOnly(tck_record_type(
- ctx,
- kvs.iter().map(|(x, v)| Ok((x.clone(), v.get_type()?))),
- )?),
- Field(r, x) => {
- match &*r.get_type()?.as_whnf() {
- ValueKind::RecordType(kts) => match kts.get(&x) {
- Some(tth) => {
- RetTypeOnly(tth.clone())
- },
- None => return mkerr(MissingRecordField(x.clone(),
- r.clone())),
- },
- // TODO: branch here only when r.get_type() is a Const
- _ => {
- match &*r.as_whnf() {
- ValueKind::UnionType(kts) => match kts.get(&x) {
- // Constructor has type T -> < x: T, ... >
- Some(Some(t)) => {
- RetTypeOnly(
- tck_pi_type(
- ctx,
- x.clone(),
- t.clone(),
- r.under_binder(x),
- )?
- )
- },
- Some(None) => {
- RetTypeOnly(r.clone())
- },
- None => {
- return mkerr(MissingUnionField(
- x.clone(),
- r.clone(),
- ))
- },
- },
- _ => {
- return mkerr(NotARecord(
- x.clone(),
- r.clone()
- ))
- },
- }
- }
- // _ => mkerr(NotARecord(
- // x,
- // r?,
- // )),
- }
- }
- Const(c) => RetWhole(const_to_value(*c)),
- Builtin(b) => RetWhole(builtin_to_value(*b)),
- BoolLit(_) => RetTypeOnly(builtin_to_value(Bool)),
- NaturalLit(_) => RetTypeOnly(builtin_to_value(Natural)),
- IntegerLit(_) => RetTypeOnly(builtin_to_value(Integer)),
- DoubleLit(_) => RetTypeOnly(builtin_to_value(Double)),
- TextLit(interpolated) => {
- let text_type = builtin_to_value(Text);
- for contents in interpolated.iter() {
- use InterpolatedTextContents::Expr;
- if let Expr(x) = contents {
- if x.get_type()? != text_type {
- return mkerr(InvalidTextInterpolation(x.clone()));
- }
- }
- }
- RetTypeOnly(text_type)
- }
- BinOp(RightBiasedRecordMerge, l, r) => {
- let l_type = l.get_type()?;
- let r_type = r.get_type()?;
-
- // Extract the LHS record type
- let l_type_borrow = l_type.as_whnf();
- let kts_x = match &*l_type_borrow {
- ValueKind::RecordType(kts) => kts,
- _ => return mkerr(MustCombineRecord(l.clone())),
- };
-
- // Extract the RHS record type
- let r_type_borrow = r_type.as_whnf();
- let kts_y = match &*r_type_borrow {
- ValueKind::RecordType(kts) => kts,
- _ => return mkerr(MustCombineRecord(r.clone())),
- };
-
- // Union the two records, prefering
- // the values found in the RHS.
- let kts = merge_maps::<_, _, _, !>(kts_x, kts_y, |_, _, r_t| {
- Ok(r_t.clone())
- })?;
-
- // Construct the final record type from the union
- RetTypeOnly(tck_record_type(
- ctx,
- kts.into_iter().map(|(x, v)| Ok((x.clone(), v))),
- )?)
- }
- BinOp(RecursiveRecordMerge, l, r) => RetTypeOnly(type_last_layer(
- ctx,
- ExprKind::BinOp(
- RecursiveRecordTypeMerge,
- l.get_type()?,
- r.get_type()?,
- ),
- Span::Artificial,
- )?),
- BinOp(RecursiveRecordTypeMerge, l, r) => {
- // Extract the LHS record type
- let borrow_l = l.as_whnf();
- let kts_x = match &*borrow_l {
- ValueKind::RecordType(kts) => kts,
- _ => {
- return mkerr(RecordTypeMergeRequiresRecordType(l.clone()))
- }
- };
-
- // Extract the RHS record type
- let borrow_r = r.as_whnf();
- let kts_y = match &*borrow_r {
- ValueKind::RecordType(kts) => kts,
- _ => {
- return mkerr(RecordTypeMergeRequiresRecordType(r.clone()))
- }
- };
-
- // Ensure that the records combine without a type error
- let kts = merge_maps(
- kts_x,
- kts_y,
- // If the Label exists for both records, then we hit the recursive case.
- |_, l: &Value, r: &Value| {
- type_last_layer(
- ctx,
- ExprKind::BinOp(
- RecursiveRecordTypeMerge,
- l.clone(),
- r.clone(),
- ),
- Span::Artificial,
- )
- },
- )?;
-
- RetWhole(tck_record_type(ctx, kts.into_iter().map(Ok))?)
- }
- BinOp(o @ ListAppend, l, r) => {
- match &*l.get_type()?.as_whnf() {
- ValueKind::AppliedBuiltin(List, _) => {}
- _ => return mkerr(BinOpTypeMismatch(*o, l.clone())),
- }
-
- if l.get_type()? != r.get_type()? {
- return mkerr(BinOpTypeMismatch(*o, r.clone()));
- }
-
- RetTypeOnly(l.get_type()?)
- }
- BinOp(Equivalence, l, r) => {
- if l.get_type()?.get_type()?.as_const() != Some(Type) {
- return mkerr(EquivalenceArgumentMustBeTerm(true, l.clone()));
- }
- if r.get_type()?.get_type()?.as_const() != Some(Type) {
- return mkerr(EquivalenceArgumentMustBeTerm(false, r.clone()));
- }
-
- if l.get_type()? != r.get_type()? {
- return mkerr(EquivalenceTypeMismatch(r.clone(), l.clone()));
- }
-
- RetWhole(Value::from_kind_and_type(
- ValueKind::Equivalence(l.clone(), r.clone()),
- Value::from_const(Type),
- ))
- }
- BinOp(o, l, r) => {
- let t = builtin_to_value(match o {
- BoolAnd => Bool,
- BoolOr => Bool,
- BoolEQ => Bool,
- BoolNE => Bool,
- NaturalPlus => Natural,
- NaturalTimes => Natural,
- TextAppend => Text,
- ListAppend => unreachable!(),
- RightBiasedRecordMerge => unreachable!(),
- RecursiveRecordMerge => unreachable!(),
- RecursiveRecordTypeMerge => unreachable!(),
- ImportAlt => unreachable!("There should remain no import alternatives in a resolved expression"),
- Equivalence => unreachable!(),
- });
-
- if l.get_type()? != t {
- return mkerr(BinOpTypeMismatch(*o, l.clone()));
- }
-
- if r.get_type()? != t {
- return mkerr(BinOpTypeMismatch(*o, r.clone()));
- }
-
- RetTypeOnly(t)
- }
- Merge(record, union, type_annot) => {
- let record_type = record.get_type()?;
- let record_borrow = record_type.as_whnf();
- let handlers = match &*record_borrow {
- ValueKind::RecordType(kts) => kts,
- _ => return mkerr(Merge1ArgMustBeRecord(record.clone())),
- };
-
- let union_type = union.get_type()?;
- let union_borrow = union_type.as_whnf();
- let variants = match &*union_borrow {
- ValueKind::UnionType(kts) => Cow::Borrowed(kts),
- ValueKind::AppliedBuiltin(syntax::Builtin::Optional, args)
- if args.len() == 1 =>
- {
- let ty = &args[0];
- let mut kts = HashMap::new();
- kts.insert("None".into(), None);
- kts.insert("Some".into(), Some(ty.clone()));
- Cow::Owned(kts)
- }
- _ => {
- return mkerr(Merge2ArgMustBeUnionOrOptional(union.clone()))
- }
- };
-
- let mut inferred_type = None;
- for (x, handler_type) in handlers {
- let handler_return_type =
- match variants.get(x) {
- // Union alternative with type
- Some(Some(variant_type)) => {
- let handler_type_borrow = handler_type.as_whnf();
- let (x, tx, tb) = match &*handler_type_borrow {
- ValueKind::Pi(x, tx, tb) => (x, tx, tb),
- _ => {
- return mkerr(NotAFunction(
- handler_type.clone(),
- ))
- }
- };
-
- if variant_type != tx {
- return mkerr(TypeMismatch(
- handler_type.clone(),
- tx.clone(),
- variant_type.clone(),
- ));
- }
-
- // Extract `tb` from under the `x` binder. Fails is `x` was free in `tb`.
- match tb.over_binder(x) {
- Some(x) => x,
- None => return mkerr(
- MergeHandlerReturnTypeMustNotBeDependent,
- ),
- }
- }
- // Union alternative without type
- Some(None) => handler_type.clone(),
- None => {
- return mkerr(MergeHandlerMissingVariant(x.clone()))
- }
- };
- match &inferred_type {
- None => inferred_type = Some(handler_return_type),
- Some(t) => {
- if t != &handler_return_type {
- return mkerr(MergeHandlerTypeMismatch);
- }
- }
- }
- }
- for x in variants.keys() {
- if !handlers.contains_key(x) {
- return mkerr(MergeVariantMissingHandler(x.clone()));
- }
- }
-
- match (inferred_type, type_annot.as_ref()) {
- (Some(t1), Some(t2)) => {
- if &t1 != t2 {
- return mkerr(MergeAnnotMismatch);
- }
- RetTypeOnly(t1)
- }
- (Some(t), None) => RetTypeOnly(t),
- (None, Some(t)) => RetTypeOnly(t.clone()),
- (None, None) => return mkerr(MergeEmptyNeedsAnnotation),
- }
- }
- ToMap(_, _) => unimplemented!("toMap"),
- Projection(record, labels) => {
- let record_type = record.get_type()?;
- let record_type_borrow = record_type.as_whnf();
- let kts = match &*record_type_borrow {
- ValueKind::RecordType(kts) => kts,
- _ => return mkerr(ProjectionMustBeRecord),
- };
-
- let mut new_kts = HashMap::new();
- for l in labels {
- match kts.get(l) {
- None => return mkerr(ProjectionMissingEntry),
- Some(t) => {
- use std::collections::hash_map::Entry;
- match new_kts.entry(l.clone()) {
- Entry::Occupied(_) => {
- return mkerr(ProjectionDuplicateField)
- }
- Entry::Vacant(e) => e.insert(t.clone()),
- }
- }
- };
- }
-
- RetTypeOnly(Value::from_kind_and_type(
- ValueKind::RecordType(new_kts),
- record_type.get_type()?,
- ))
- }
- ProjectionByExpr(_, _) => unimplemented!("selection by expression"),
- Completion(_, _) => unimplemented!("record completion"),
- };
-
- Ok(match ret {
- RetTypeOnly(typ) => Value::from_kind_and_type_and_span(
- ValueKind::PartialExpr(e),
- typ,
- span,
- ),
- RetWhole(v) => v.with_span(span),
- })
-}
-
-/// `type_of` 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.
-pub(crate) fn typecheck(e: Expr<Normalized>) -> Result<Value, TypeError> {
- type_with(&TypecheckContext::new(), e)
-}
-
-pub(crate) fn typecheck_with(
- expr: Expr<Normalized>,
- ty: Expr<Normalized>,
-) -> Result<Value, TypeError> {
- typecheck(expr.rewrap(ExprKind::Annot(expr.clone(), ty)))
-}
diff --git a/dhall/src/semantics/phase/resolve.rs b/dhall/src/semantics/resolve.rs
index cc4a024..3acf114 100644
--- a/dhall/src/semantics/phase/resolve.rs
+++ b/dhall/src/semantics/resolve.rs
@@ -2,9 +2,9 @@ use std::collections::HashMap;
use std::path::{Path, PathBuf};
use crate::error::{Error, ImportError};
-use crate::semantics::phase::{Normalized, NormalizedExpr, Parsed, Resolved};
use crate::syntax;
use crate::syntax::{FilePath, ImportLocation, URL};
+use crate::{Normalized, NormalizedExpr, Parsed, Resolved};
type Import = syntax::Import<NormalizedExpr>;
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-06 06:03:03 +0000