diff options
Diffstat (limited to '')
-rw-r--r-- | dhall/src/binary.rs | 14 | ||||
-rw-r--r-- | dhall/src/expr.rs | 3 | ||||
-rw-r--r-- | dhall/src/lib.rs | 1 | ||||
-rw-r--r-- | dhall/src/normalize.rs | 1093 | ||||
-rw-r--r-- | dhall/src/typecheck.rs | 90 |
5 files changed, 806 insertions, 395 deletions
diff --git a/dhall/src/binary.rs b/dhall/src/binary.rs index c12aa2a..7ded3a5 100644 --- a/dhall/src/binary.rs +++ b/dhall/src/binary.rs @@ -42,12 +42,12 @@ fn cbor_value_to_dhall(data: &cbor::Value) -> Result<ParsedExpr, DecodeError> { Var(V(l, *n as usize)) } [U64(0), f, args..] => { - let f = cbor_value_to_dhall(&f)?; - let args = args - .iter() - .map(cbor_value_to_dhall) - .collect::<Result<Vec<_>, _>>()?; - App(f, args) + let mut f = cbor_value_to_dhall(&f)?; + for a in args { + let a = cbor_value_to_dhall(&a)?; + f = rc(App(f, a)) + } + return Ok(f); } [U64(1), x, y] => { let x = cbor_value_to_dhall(&x)?; @@ -111,7 +111,7 @@ fn cbor_value_to_dhall(data: &cbor::Value) -> Result<ParsedExpr, DecodeError> { } [U64(5), Null, x] => { let x = cbor_value_to_dhall(&x)?; - NEOptionalLit(x) + SomeLit(x) } [U64(5), t, x] => { let x = cbor_value_to_dhall(&x)?; diff --git a/dhall/src/expr.rs b/dhall/src/expr.rs index 5885359..bb1a4e4 100644 --- a/dhall/src/expr.rs +++ b/dhall/src/expr.rs @@ -107,9 +107,6 @@ impl<'a> Typed<'a> { pub(crate) fn as_expr(&self) -> &SubExpr<X, Normalized<'a>> { &self.0 } - pub(crate) fn into_expr(self) -> SubExpr<X, Normalized<'a>> { - self.0 - } } #[doc(hidden)] diff --git a/dhall/src/lib.rs b/dhall/src/lib.rs index 544df6e..c85b962 100644 --- a/dhall/src/lib.rs +++ b/dhall/src/lib.rs @@ -3,6 +3,7 @@ #![feature(slice_patterns)] #![feature(label_break_value)] #![feature(non_exhaustive)] +#![feature(bind_by_move_pattern_guards)] #![cfg_attr(test, feature(custom_inner_attributes))] #![allow( clippy::type_complexity, diff --git a/dhall/src/normalize.rs b/dhall/src/normalize.rs index 1561f01..f092c4d 100644 --- a/dhall/src/normalize.rs +++ b/dhall/src/normalize.rs @@ -1,8 +1,18 @@ #![allow(non_snake_case)] -use crate::expr::*; -use dhall_core::*; +use std::collections::BTreeMap; +use std::rc::Rc; + +use dhall_core::context::Context; +use dhall_core::{ + rc, shift, shift0, Builtin, ExprF, Integer, InterpolatedText, + InterpolatedTextContents, Label, Natural, SubExpr, V, X, +}; use dhall_generator as dhall; -use std::fmt; + +use crate::expr::{Normalized, Typed}; + +type InputSubExpr = SubExpr<X, Normalized<'static>>; +type OutputSubExpr = SubExpr<X, X>; impl<'a> Typed<'a> { pub fn normalize(self) -> Normalized<'a> { @@ -19,323 +29,762 @@ impl<'a> Typed<'a> { } } -fn apply_builtin<N, E>(b: Builtin, args: &[Expr<N, E>]) -> WhatNext<N, E> -where - N: fmt::Debug + Clone, - E: fmt::Debug + Clone, -{ +fn shift0_mut<N, E>(delta: isize, label: &Label, in_expr: &mut SubExpr<N, E>) { + let new_expr = shift0(delta, label, &in_expr); + std::mem::replace(in_expr, new_expr); +} + +fn shift_mut<N, E>(delta: isize, var: &V<Label>, in_expr: &mut SubExpr<N, E>) { + let new_expr = shift(delta, var, &in_expr); + std::mem::replace(in_expr, new_expr); +} + +fn apply_builtin(b: Builtin, args: Vec<WHNF>) -> WHNF { use dhall_core::Builtin::*; - use dhall_core::ExprF::*; - use WhatNext::*; - let (ret, rest) = match (b, args) { - (OptionalNone, [t, rest..]) => (rc(EmptyOptionalLit(t.roll())), rest), - (NaturalIsZero, [NaturalLit(n), rest..]) => { - (rc(BoolLit(*n == 0)), rest) - } - (NaturalEven, [NaturalLit(n), rest..]) => { - (rc(BoolLit(*n % 2 == 0)), rest) - } - (NaturalOdd, [NaturalLit(n), rest..]) => { - (rc(BoolLit(*n % 2 != 0)), rest) - } - (NaturalToInteger, [NaturalLit(n), rest..]) => { - (rc(IntegerLit(*n as isize)), rest) - } - (NaturalShow, [NaturalLit(n), rest..]) => { - (rc(TextLit(n.to_string().into())), rest) - } - (ListLength, [_, EmptyListLit(_), rest..]) => (rc(NaturalLit(0)), rest), - (ListLength, [_, NEListLit(ys), rest..]) => { - (rc(NaturalLit(ys.len())), rest) - } - (ListHead, [_, EmptyListLit(t), rest..]) => { - (rc(EmptyOptionalLit(t.clone())), rest) - } - (ListHead, [_, NEListLit(ys), rest..]) => { - (rc(NEOptionalLit(ys.first().unwrap().clone())), rest) - } - (ListLast, [_, EmptyListLit(t), rest..]) => { - (rc(EmptyOptionalLit(t.clone())), rest) - } - (ListLast, [_, NEListLit(ys), rest..]) => { - (rc(NEOptionalLit(ys.last().unwrap().clone())), rest) - } - (ListReverse, [_, EmptyListLit(t), rest..]) => { - (rc(EmptyListLit(t.clone())), rest) - } - (ListReverse, [_, NEListLit(ys), rest..]) => { - let ys = ys.iter().rev().cloned().collect(); - (rc(NEListLit(ys)), rest) - } - (ListIndexed, [_, EmptyListLit(t), rest..]) => ( - dhall::subexpr!([] : List ({ index : Natural, value : t })), - rest, + use WHNF::*; + + let ret = match b { + OptionalNone => improved_slice_patterns::match_vec!(args; + [t] => EmptyOptionalLit(Now::from_whnf(t)), ), - (ListIndexed, [_, NEListLit(xs), rest..]) => { - let xs = xs - .iter() - .cloned() - .enumerate() - .map(|(i, e)| { - let i = rc(NaturalLit(i)); - dhall::subexpr!({ index = i, value = e }) - }) - .collect(); - (rc(NEListLit(xs)), rest) - } - (ListBuild, [a0, g, rest..]) => { - 'ret: { - if let App(f2, args2) = g { - if let (Builtin(ListFold), [_, x, rest_inner..]) = - (f2.as_ref(), args2.as_slice()) - { - // fold/build fusion - break 'ret ( - rc(App(x.clone(), rest_inner.to_vec())), - rest, - ); - } - }; - let a0 = a0.roll(); - let a1 = shift(1, &V("x".into(), 0), &a0); - let g = g.roll(); - break 'ret ( - dhall::subexpr!( - g - (List a0) - (λ(x : a0) -> λ(xs : List a1) -> [ x ] # xs) - ([] : List a0) + NaturalIsZero => improved_slice_patterns::match_vec!(args; + [NaturalLit(n)] => BoolLit(n == 0), + ), + NaturalEven => improved_slice_patterns::match_vec!(args; + [NaturalLit(n)] => BoolLit(n % 2 == 0), + ), + NaturalOdd => improved_slice_patterns::match_vec!(args; + [NaturalLit(n)] => BoolLit(n % 2 != 0), + ), + NaturalToInteger => improved_slice_patterns::match_vec!(args; + [NaturalLit(n)] => IntegerLit(n as isize), + ), + NaturalShow => improved_slice_patterns::match_vec!(args; + [NaturalLit(n)] => { + TextLit(vec![InterpolatedTextContents::Text(n.to_string())]) + } + ), + ListLength => improved_slice_patterns::match_vec!(args; + [_, EmptyListLit(_)] => NaturalLit(0), + [_, NEListLit(xs)] => NaturalLit(xs.len()), + ), + ListHead => improved_slice_patterns::match_vec!(args; + [_, EmptyListLit(n)] => EmptyOptionalLit(n), + [_, NEListLit(xs)] => { + NEOptionalLit(xs.into_iter().next().unwrap()) + } + ), + ListLast => improved_slice_patterns::match_vec!(args; + [_, EmptyListLit(n)] => EmptyOptionalLit(n), + [_, NEListLit(xs)] => { + NEOptionalLit(xs.into_iter().rev().next().unwrap()) + } + ), + ListReverse => improved_slice_patterns::match_vec!(args; + [_, EmptyListLit(n)] => EmptyListLit(n), + [_, NEListLit(xs)] => { + let mut xs = xs; + xs.reverse(); + NEListLit(xs) + } + ), + ListIndexed => improved_slice_patterns::match_vec!(args; + [_, EmptyListLit(t)] => { + let mut kts = BTreeMap::new(); + kts.insert( + "index".into(), + Now::from_whnf( + WHNF::from_builtin(Natural) ), - rest, ); + kts.insert("value".into(), t); + EmptyListLit(Now::from_whnf(RecordType(kts))) + }, + [_, NEListLit(xs)] => { + let xs = xs + .into_iter() + .enumerate() + .map(|(i, e)| { + let i = NaturalLit(i); + let mut kvs = BTreeMap::new(); + kvs.insert("index".into(), Now::from_whnf(i)); + kvs.insert("value".into(), e); + Now::from_whnf(RecordLit(kvs)) + }) + .collect(); + NEListLit(xs) } - } - (OptionalBuild, [a0, g, rest..]) => { - 'ret: { - if let App(f2, args2) = g { - if let (Builtin(OptionalFold), [_, x, rest_inner..]) = - (f2.as_ref(), args2.as_slice()) - { - // fold/build fusion - break 'ret ( - rc(App(x.clone(), rest_inner.to_vec())), - rest, - ); + ), + ListBuild => improved_slice_patterns::match_vec!(args; + // fold/build fusion + [_, WHNF::AppliedBuiltin(ListFold, args)] => { + let mut args = args; + if args.len() >= 2 { + args.remove(1) + } else { + // Do we really need to handle this case ? + unimplemented!() + } + }, + [t, g] => g + .app(WHNF::from_builtin(List).app(t.clone())) + .app(ListConsClosure(Now::from_whnf(t.clone()), None)) + .app(EmptyListLit(Now::from_whnf(t))), + ), + ListFold => improved_slice_patterns::match_vec!(args; + // fold/build fusion + [_, WHNF::AppliedBuiltin(ListBuild, args)] => { + let mut args = args; + if args.len() >= 2 { + args.remove(1) + } else { + unimplemented!() + } + }, + [_, EmptyListLit(_), _, _, nil] => nil, + [_, NEListLit(xs), _, cons, nil] => { + let mut v = nil; + for x in xs.into_iter().rev() { + v = cons.clone().app(x.normalize()).app(v); + } + v + } + ), + OptionalBuild => improved_slice_patterns::match_vec!(args; + // fold/build fusion + [_, WHNF::AppliedBuiltin(OptionalFold, args)] => { + let mut args = args; + if args.len() >= 2 { + args.remove(1) + } else { + unimplemented!() + } + }, + [t, g] => g + .app(WHNF::from_builtin(Optional).app(t.clone())) + .app(OptionalSomeClosure(Now::from_whnf(t.clone()))) + .app(EmptyOptionalLit(Now::from_whnf(t))), + ), + OptionalFold => improved_slice_patterns::match_vec!(args; + // fold/build fusion + [_, WHNF::AppliedBuiltin(OptionalBuild, args)] => { + let mut args = args; + if args.len() >= 2 { + args.remove(1) + } else { + unimplemented!() + } + }, + [_, EmptyOptionalLit(_), _, _, nothing] => { + nothing + }, + [_, NEOptionalLit(x), _, just, _] => { + just.app(x.normalize()) + } + ), + NaturalBuild => improved_slice_patterns::match_vec!(args; + // fold/build fusion + [WHNF::AppliedBuiltin(NaturalFold, args)] => { + let mut args = args; + if args.len() >= 1 { + args.remove(0) + } else { + unimplemented!() + } + }, + [g] => g + .app(WHNF::from_builtin(Natural)) + .app(NaturalSuccClosure) + .app(NaturalLit(0)), + ), + NaturalFold => improved_slice_patterns::match_vec!(args; + // fold/build fusion + [WHNF::AppliedBuiltin(NaturalBuild, args)] => { + let mut args = args; + if args.len() >= 1 { + args.remove(0) + } else { + unimplemented!() + } + }, + [NaturalLit(0), _, _, zero] => zero, + [NaturalLit(n), t, succ, zero] => { + let fold = WHNF::from_builtin(NaturalFold) + .app(NaturalLit(n - 1)) + .app(t) + .app(succ.clone()) + .app(zero); + succ.app(fold) + }, + ), + _ => Err(args), + }; + + match ret { + Ok(x) => x, + Err(args) => AppliedBuiltin(b, args), + } +} + +#[derive(Debug, Clone)] +enum EnvItem { + Expr(WHNF), + Skip(usize), +} + +#[derive(Debug, Clone)] +struct NormalizationContext(Rc<Context<Label, EnvItem>>); + +impl NormalizationContext { + fn new() -> Self { + NormalizationContext(Rc::new(Context::new())) + } + fn insert(&self, x: &Label, e: WHNF) -> Self { + NormalizationContext(Rc::new( + self.0.insert(x.clone(), EnvItem::Expr(e)), + )) + } + fn skip(&self, x: &Label) -> Self { + NormalizationContext(Rc::new( + self.0 + .map(|l, e| { + use EnvItem::*; + match e { + Expr(e) => { + let mut e = e.clone(); + e.shift0(1, x); + Expr(e) + } + Skip(n) if l == x => Skip(*n + 1), + Skip(n) => Skip(*n), } - }; - let a0 = a0.roll(); - let g = g.roll(); - break 'ret ( - dhall::subexpr!( - g - (Optional a0) - (λ(x: a0) -> Some x) - (None a0) - ), - rest, - ); + }) + .insert(x.clone(), EnvItem::Skip(0)), + )) + } + fn lookup(&self, var: &V<Label>) -> WHNF { + let V(x, n) = var; + match self.0.lookup(x, *n) { + Some(EnvItem::Expr(e)) => e.clone(), + Some(EnvItem::Skip(m)) => { + WHNF::Expr(rc(ExprF::Var(V(x.clone(), *m)))) } + None => WHNF::Expr(rc(ExprF::Var(V(x.clone(), *n)))), } - (ListFold, [_, EmptyListLit(_), _, _, nil, rest..]) => { - (nil.roll(), rest) - } - (ListFold, [_, NEListLit(xs), _, cons, nil, rest..]) => ( - xs.iter().rev().fold(nil.roll(), |acc, x| { - let x = x.clone(); - let acc = acc.clone(); - let cons = cons.roll(); - dhall::subexpr!(cons x acc) - }), - rest, - ), - // // fold/build fusion - // (ListFold, [_, App(box Builtin(ListBuild), [_, x, rest..]), rest..]) => { - // normalize_ref(&App(bx(x.clone()), rest.to_vec())) - // } - (OptionalFold, [_, NEOptionalLit(x), _, just, _, rest..]) => { - let x = x.clone(); - let just = just.roll(); - (dhall::subexpr!(just x), rest) + } +} + +/// A semantic value. This is partially redundant with `dhall_core::Expr`, on purpose. `Expr` 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 normalizing, +/// but only construct `WHNF`s. +/// +/// WHNFs store subexpressions unnormalized, to enable lazy normalization. They approximate +/// what's called Weak Head Normal-Form (WHNF). This means that the expression is normalized as +/// little as possible, but just enough to know the first constructor of the normal form. This is +/// identical to full normalization for simple types like integers, but for e.g. a record literal +/// this means knowing just the field names. +/// +/// Each variant captures the relevant contexts when it is constructed. Conceptually each +/// subexpression has its own context, but in practice some contexts can be shared when sensible, to +/// avoid unnecessary allocations. +#[derive(Debug, Clone)] +enum WHNF { + /// Closures + Lam(Label, Now, (NormalizationContext, InputSubExpr)), + AppliedBuiltin(Builtin, Vec<WHNF>), + /// `λ(x: a) -> Some x` + OptionalSomeClosure(Now), + /// `λ(x : a) -> λ(xs : List a) -> [ x ] # xs` + /// `λ(xs : List a) -> [ x ] # xs` + ListConsClosure(Now, Option<Now>), + /// `λ(x : Natural) -> x + 1` + NaturalSuccClosure, + + BoolLit(bool), + NaturalLit(Natural), + IntegerLit(Integer), + EmptyOptionalLit(Now), + NEOptionalLit(Now), + EmptyListLit(Now), + NEListLit(Vec<Now>), + RecordLit(BTreeMap<Label, Now>), + RecordType(BTreeMap<Label, Now>), + UnionType(NormalizationContext, BTreeMap<Label, Option<InputSubExpr>>), + UnionConstructor( + NormalizationContext, + Label, + BTreeMap<Label, Option<InputSubExpr>>, + ), + UnionLit( + Label, + Now, + (NormalizationContext, BTreeMap<Label, Option<InputSubExpr>>), + ), + TextLit(Vec<InterpolatedTextContents<Now>>), + Expr(OutputSubExpr), +} + +impl WHNF { + /// Convert the value back to a (normalized) syntactic expression + fn normalize_to_expr(self) -> OutputSubExpr { + match self { + WHNF::Lam(x, t, (ctx, e)) => { + let ctx2 = ctx.skip(&x); + rc(ExprF::Lam( + x.clone(), + t.normalize().normalize_to_expr(), + normalize_whnf(ctx2, e).normalize_to_expr(), + )) + } + WHNF::AppliedBuiltin(b, args) => { + let mut e = WHNF::Expr(rc(ExprF::Builtin(b))); + for v in args { + e = e.app(v); + } + e.normalize_to_expr() + } + WHNF::OptionalSomeClosure(n) => { + let a = n.normalize().normalize_to_expr(); + dhall::subexpr!(λ(x: a) -> Some x) + } + WHNF::ListConsClosure(n, None) => { + let a = n.normalize().normalize_to_expr(); + // Avoid accidental capture of the new `x` variable + let a1 = shift0(1, &"x".into(), &a); + dhall::subexpr!(λ(x : a) -> λ(xs : List a1) -> [ x ] # xs) + } + WHNF::ListConsClosure(n, Some(v)) => { + let v = v.normalize().normalize_to_expr(); + let a = n.normalize().normalize_to_expr(); + dhall::subexpr!(λ(xs : List a) -> [ v ] # xs) + } + WHNF::NaturalSuccClosure => { + dhall::subexpr!(λ(x : Natural) -> x + 1) + } + WHNF::BoolLit(b) => rc(ExprF::BoolLit(b)), + WHNF::NaturalLit(n) => rc(ExprF::NaturalLit(n)), + WHNF::IntegerLit(n) => rc(ExprF::IntegerLit(n)), + WHNF::EmptyOptionalLit(n) => { + WHNF::Expr(rc(ExprF::Builtin(Builtin::OptionalNone))) + .app(n.normalize()) + .normalize_to_expr() + } + WHNF::NEOptionalLit(n) => { + rc(ExprF::SomeLit(n.normalize().normalize_to_expr())) + } + WHNF::EmptyListLit(n) => { + rc(ExprF::EmptyListLit(n.normalize().normalize_to_expr())) + } + WHNF::NEListLit(elts) => rc(ExprF::NEListLit( + elts.into_iter() + .map(|n| n.normalize().normalize_to_expr()) + .collect(), + )), + WHNF::RecordLit(kvs) => rc(ExprF::RecordLit( + kvs.into_iter() + .map(|(k, v)| (k, v.normalize().normalize_to_expr())) + .collect(), + )), + WHNF::RecordType(kts) => rc(ExprF::RecordType( + kts.into_iter() + .map(|(k, v)| (k, v.normalize().normalize_to_expr())) + .collect(), + )), + WHNF::UnionType(ctx, kts) => rc(ExprF::UnionType( + kts.into_iter() + .map(|(k, v)| { + ( + k, + v.map(|v| { + normalize_whnf(ctx.clone(), v) + .normalize_to_expr() + }), + ) + }) + .collect(), + )), + WHNF::UnionConstructor(ctx, l, kts) => { + let kts = kts + .into_iter() + .map(|(k, v)| { + ( + k, + v.map(|v| { + normalize_whnf(ctx.clone(), v) + .normalize_to_expr() + }), + ) + }) + .collect(); + rc(ExprF::Field(rc(ExprF::UnionType(kts)), l)) + } + WHNF::UnionLit(l, v, (kts_ctx, kts)) => rc(ExprF::UnionLit( + l, + v.normalize().normalize_to_expr(), + kts.into_iter() + .map(|(k, v)| { + ( + k, + v.map(|v| { + normalize_whnf(kts_ctx.clone(), v) + .normalize_to_expr() + }), + ) + }) + .collect(), + )), + WHNF::TextLit(elts) => { + fn normalize_textlit( + elts: Vec<InterpolatedTextContents<Now>>, + ) -> InterpolatedText<OutputSubExpr> { + elts.into_iter() + .flat_map(|contents| { + use InterpolatedTextContents::{Expr, Text}; + let new_interpolated = match contents { + Expr(n) => match n.normalize() { + WHNF::TextLit(elts2) => { + normalize_textlit(elts2) + } + e => InterpolatedText::from(( + String::new(), + vec![( + e.normalize_to_expr(), + String::new(), + )], + )), + }, + Text(s) => InterpolatedText::from(s), + }; + new_interpolated.into_iter() + }) + .collect() + } + + rc(ExprF::TextLit(normalize_textlit(elts))) + } + WHNF::Expr(e) => e, } - (OptionalFold, [_, EmptyOptionalLit(_), _, _, nothing, rest..]) => { - (nothing.roll(), rest) + } + + /// Apply to a value + fn app(self, val: WHNF) -> WHNF { + match (self, val) { + (WHNF::Lam(x, _, (ctx, e)), val) => { + let ctx2 = ctx.insert(&x, val); + normalize_whnf(ctx2, e) + } + (WHNF::AppliedBuiltin(b, mut args), val) => { + args.push(val); + apply_builtin(b, args) + } + (WHNF::OptionalSomeClosure(_), val) => { + WHNF::NEOptionalLit(Now::from_whnf(val)) + } + (WHNF::ListConsClosure(t, None), val) => { + WHNF::ListConsClosure(t, Some(Now::from_whnf(val))) + } + (WHNF::ListConsClosure(_, Some(x)), WHNF::EmptyListLit(_)) => { + WHNF::NEListLit(vec![x]) + } + (WHNF::ListConsClosure(_, Some(x)), WHNF::NEListLit(mut xs)) => { + xs.insert(0, x); + WHNF::NEListLit(xs) + } + (WHNF::NaturalSuccClosure, WHNF::NaturalLit(n)) => { + WHNF::NaturalLit(n + 1) + } + (WHNF::UnionConstructor(ctx, l, kts), val) => { + WHNF::UnionLit(l, Now::from_whnf(val), (ctx, kts)) + } + // Can't do anything useful, convert to expr + (f, a) => WHNF::Expr(rc(ExprF::App( + f.normalize_to_expr(), + a.normalize_to_expr(), + ))), } - // // fold/build fusion - // (OptionalFold, [_, App(box Builtin(OptionalBuild), [_, x, rest..]), rest..]) => { - // normalize_ref(&App(bx(x.clone()), rest.to_vec())) - // } - (NaturalBuild, [g, rest..]) => { - 'ret: { - if let App(f2, args2) = g { - if let (Builtin(NaturalFold), [x, rest_inner..]) = - (f2.as_ref(), args2.as_slice()) - { - // fold/build fusion - break 'ret ( - rc(App(x.clone(), rest_inner.to_vec())), - rest, - ); + } + + fn from_builtin(b: Builtin) -> WHNF { + WHNF::AppliedBuiltin(b, vec![]) + } + + fn shift0(&mut self, delta: isize, label: &Label) { + match self { + WHNF::NaturalSuccClosure + | WHNF::BoolLit(_) + | WHNF::NaturalLit(_) + | WHNF::IntegerLit(_) => {} + WHNF::EmptyOptionalLit(n) + | WHNF::NEOptionalLit(n) + | WHNF::OptionalSomeClosure(n) + | WHNF::EmptyListLit(n) => { + n.shift0(delta, label); + } + WHNF::Lam(_, t, (_, e)) => { + t.shift0(delta, label); + shift_mut(delta, &V(label.clone(), 1), e); + } + WHNF::AppliedBuiltin(_, args) => { + for x in args.iter_mut() { + x.shift0(delta, label); + } + } + WHNF::ListConsClosure(t, v) => { + t.shift0(delta, label); + for x in v.iter_mut() { + x.shift0(delta, label); + } + } + WHNF::NEListLit(elts) => { + for x in elts.iter_mut() { + x.shift0(delta, label); + } + } + WHNF::RecordLit(kvs) | WHNF::RecordType(kvs) => { + for x in kvs.values_mut() { + x.shift0(delta, label); + } + } + WHNF::UnionType(_, kts) | WHNF::UnionConstructor(_, _, kts) => { + for x in kts.values_mut().flat_map(|opt| opt) { + shift0_mut(delta, label, x); + } + } + WHNF::UnionLit(_, v, (_, kts)) => { + v.shift0(delta, label); + for x in kts.values_mut().flat_map(|opt| opt) { + shift0_mut(delta, label, x); + } + } + WHNF::TextLit(elts) => { + for x in elts.iter_mut() { + use InterpolatedTextContents::{Expr, Text}; + match x { + Expr(n) => n.shift0(delta, label), + Text(_) => {} } - }; - let g = g.roll(); - break 'ret ( - dhall::subexpr!(g Natural (λ(x : Natural) -> x + 1) 0), - rest, - ); + } } + WHNF::Expr(e) => shift0_mut(delta, label, e), } - (NaturalFold, [NaturalLit(0), _, _, zero, rest..]) => { - (zero.roll(), rest) - } - (NaturalFold, [NaturalLit(n), t, succ, zero, rest..]) => { - let fold = rc(Builtin(NaturalFold)); - let n = rc(NaturalLit(n - 1)); - let t = t.roll(); - let succ = succ.roll(); - let zero = zero.roll(); - (dhall::subexpr!(succ (fold n t succ zero)), rest) - } - // (NaturalFold, Some(App(f2, args2)), _) => { - // match (f2.as_ref(), args2.as_slice()) { - // // fold/build fusion - // (Builtin(NaturalBuild), [x, rest..]) => { - // rc(App(x.clone(), rest.to_vec())) - // } - // _ => return rc(App(f, args)), - // } - // } - _ => return DoneAsIs, - }; - // Put the remaining arguments back and eval again. In most cases - // ret will not be of a form that can be applied, so this won't go very deep. - // In lots of cases, there are no remaining args so this cann will just return ret. - let rest: Vec<SubExpr<N, E>> = rest.iter().map(ExprF::roll).collect(); - Continue(ExprF::App(ret, rest)) + } } -// Small enum to help with being DRY -enum WhatNext<'a, N, E> { - // Recurse on this expression - Continue(Expr<N, E>), - ContinueSub(SubExpr<N, E>), - // The following expression is the normal form - Done(Expr<N, E>), - DoneRef(&'a Expr<N, E>), - DoneRefSub(&'a SubExpr<N, E>), - // The current expression is already in normal form - DoneAsIs, +/// Normalize-on-write smart container. Contains either a (partially) normalized value or a +/// non-normalized value alongside a normalization context. +/// The name is a pun on std::borrow::Cow. +#[derive(Debug, Clone)] +enum Now { + Normalized(Box<WHNF>), + Unnormalized(NormalizationContext, InputSubExpr), } -fn normalize_ref(expr: &Expr<X, Normalized<'static>>) -> Expr<X, X> { - use dhall_core::BinOp::*; - use dhall_core::ExprF::*; - // Recursively normalize all subexpressions - let expr: ExprF<Expr<X, X>, Label, X, Normalized<'static>> = - expr.map_ref_simple(|e| normalize_ref(e.as_ref())); - - use WhatNext::*; - // TODO: match by move - let what_next = match &expr { - Let(f, _, r, b) => { - let vf0 = &V(f.clone(), 0); - // TODO: use a context - ContinueSub(subst_shift(vf0, &r.roll(), &b.roll())) +impl Now { + fn new(ctx: NormalizationContext, e: InputSubExpr) -> Now { + Now::Unnormalized(ctx, e) + } + + fn from_whnf(v: WHNF) -> Now { + Now::Normalized(Box::new(v)) + } + + fn normalize(self) -> WHNF { + match self { + Now::Normalized(v) => *v, + Now::Unnormalized(ctx, e) => normalize_whnf(ctx, e), + } + } + + fn shift0(&mut self, delta: isize, label: &Label) { + match self { + Now::Normalized(v) => v.shift0(delta, label), + Now::Unnormalized(_, e) => shift0_mut(delta, label, e), + } + } +} + +/// Reduces the imput expression to WHNF. See doc on `WHNF` for details. +fn normalize_whnf(ctx: NormalizationContext, expr: InputSubExpr) -> WHNF { + match expr.as_ref() { + ExprF::Var(v) => ctx.lookup(&v), + ExprF::Annot(x, _) => normalize_whnf(ctx, x.clone()), + ExprF::Note(_, e) => normalize_whnf(ctx, e.clone()), + // TODO: wasteful to retraverse everything + ExprF::Embed(e) => normalize_whnf(ctx, e.0.embed_absurd()), + ExprF::Let(x, _, r, b) => { + let r = normalize_whnf(ctx.clone(), r.clone()); + normalize_whnf(ctx.insert(x, r), b.clone()) + } + ExprF::Lam(x, t, e) => WHNF::Lam( + x.clone(), + Now::new(ctx.clone(), t.clone()), + (ctx, e.clone()), + ), + ExprF::Builtin(b) => WHNF::AppliedBuiltin(*b, vec![]), + ExprF::BoolLit(b) => WHNF::BoolLit(*b), + ExprF::NaturalLit(n) => WHNF::NaturalLit(*n), + ExprF::OldOptionalLit(None, e) => { + WHNF::EmptyOptionalLit(Now::new(ctx, e.clone())) } - Annot(x, _) => DoneRef(x), - Note(_, e) => DoneRef(e), - App(f, args) if args.is_empty() => DoneRef(f), - App(App(f, args1), args2) => Continue(App( - f.clone(), - args1 - .iter() - .cloned() - .chain(args2.iter().map(ExprF::roll)) + ExprF::OldOptionalLit(Some(e), _) => { + WHNF::NEOptionalLit(Now::new(ctx, e.clone())) + } + ExprF::SomeLit(e) => WHNF::NEOptionalLit(Now::new(ctx, e.clone())), + ExprF::EmptyListLit(e) => WHNF::EmptyListLit(Now::new(ctx, e.clone())), + ExprF::NEListLit(elts) => WHNF::NEListLit( + elts.iter() + .map(|e| Now::new(ctx.clone(), e.clone())) .collect(), - )), - App(Builtin(b), args) => apply_builtin(*b, args), - App(Lam(x, _, b), args) => { - let mut iter = args.iter(); - // We know args is nonempty - let a = iter.next().unwrap(); - // Beta reduce - let vx0 = &V(x.clone(), 0); - let b2 = subst_shift(vx0, &a.roll(), &b); - Continue(App(b2, iter.map(ExprF::roll).collect())) + ), + ExprF::RecordLit(kvs) => WHNF::RecordLit( + kvs.iter() + .map(|(k, e)| (k.clone(), Now::new(ctx.clone(), e.clone()))) + .collect(), + ), + ExprF::UnionType(kvs) => WHNF::UnionType(ctx, kvs.clone()), + ExprF::UnionLit(l, x, kts) => WHNF::UnionLit( + l.clone(), + Now::new(ctx.clone(), x.clone()), + (ctx, kts.clone()), + ), + ExprF::TextLit(elts) => WHNF::TextLit( + elts.iter() + .map(|contents| { + use InterpolatedTextContents::{Expr, Text}; + match contents { + Expr(n) => Expr(Now::new(ctx.clone(), n.clone())), + Text(s) => Text(s.clone()), + } + }) + .collect(), + ), + ExprF::BoolIf(b, e1, e2) => { + let b = normalize_whnf(ctx.clone(), b.clone()); + match b { + WHNF::BoolLit(true) => normalize_whnf(ctx, e1.clone()), + WHNF::BoolLit(false) => normalize_whnf(ctx, e2.clone()), + b => { + let e1 = normalize_whnf(ctx.clone(), e1.clone()); + let e2 = normalize_whnf(ctx, e2.clone()); + match (e1, e2) { + (WHNF::BoolLit(true), WHNF::BoolLit(false)) => b, + (e1, e2) => { + normalize_last_layer(ExprF::BoolIf(b, e1, e2)) + } + } + } + } } - App(UnionConstructor(l, kts), args) => { - let mut iter = args.iter(); - // We know args is nonempty - let a = iter.next().unwrap(); - let e = rc(UnionLit(l.clone(), rc(a.clone()), kts.clone())); - Continue(App(e, iter.map(ExprF::roll).collect())) + expr => { + // Recursively normalize subexpressions + let expr: ExprF<WHNF, Label, X, X> = expr + .map_ref_with_special_handling_of_binders( + |e| normalize_whnf(ctx.clone(), e.clone()), + |x, e| normalize_whnf(ctx.skip(x), e.clone()), + X::clone, + |_| unreachable!(), + Label::clone, + ); + + normalize_last_layer(expr) } - BoolIf(BoolLit(true), t, _) => DoneRef(t), - BoolIf(BoolLit(false), _, f) => DoneRef(f), - // TODO: interpolation - // TextLit(t) => - OldOptionalLit(None, t) => Done(EmptyOptionalLit(t.roll())), - OldOptionalLit(Some(x), _) => Done(NEOptionalLit(x.roll())), - BinOp(BoolAnd, BoolLit(x), BoolLit(y)) => Done(BoolLit(*x && *y)), - BinOp(BoolOr, BoolLit(x), BoolLit(y)) => Done(BoolLit(*x || *y)), - BinOp(BoolEQ, BoolLit(x), BoolLit(y)) => Done(BoolLit(x == y)), - BinOp(BoolNE, BoolLit(x), BoolLit(y)) => Done(BoolLit(x != y)), - BinOp(NaturalPlus, NaturalLit(x), NaturalLit(y)) => { - Done(NaturalLit(x + y)) + } +} + +/// When all sub-expressions have been (partially) normalized, eval the remaining toplevel layer. +fn normalize_last_layer(expr: ExprF<WHNF, Label, X, X>) -> WHNF { + use dhall_core::BinOp::*; + use WHNF::*; + + match expr { + ExprF::App(v, a) => v.app(a), + + ExprF::BinOp(BoolAnd, BoolLit(true), y) => y, + ExprF::BinOp(BoolAnd, x, BoolLit(true)) => x, + ExprF::BinOp(BoolAnd, BoolLit(false), _) => BoolLit(false), + ExprF::BinOp(BoolAnd, _, BoolLit(false)) => BoolLit(false), + ExprF::BinOp(BoolOr, BoolLit(true), _) => BoolLit(true), + ExprF::BinOp(BoolOr, _, BoolLit(true)) => BoolLit(true), + ExprF::BinOp(BoolOr, BoolLit(false), y) => y, + ExprF::BinOp(BoolOr, x, BoolLit(false)) => x, + ExprF::BinOp(BoolEQ, BoolLit(true), y) => y, + ExprF::BinOp(BoolEQ, x, BoolLit(true)) => x, + ExprF::BinOp(BoolNE, BoolLit(false), y) => y, + ExprF::BinOp(BoolNE, x, BoolLit(false)) => x, + ExprF::BinOp(BoolEQ, BoolLit(x), BoolLit(y)) => BoolLit(x == y), + ExprF::BinOp(BoolNE, BoolLit(x), BoolLit(y)) => BoolLit(x != y), + + ExprF::BinOp(NaturalPlus, NaturalLit(0), y) => y, + ExprF::BinOp(NaturalPlus, x, NaturalLit(0)) => x, + ExprF::BinOp(NaturalTimes, NaturalLit(0), _) => NaturalLit(0), + ExprF::BinOp(NaturalTimes, _, NaturalLit(0)) => NaturalLit(0), + ExprF::BinOp(NaturalTimes, NaturalLit(1), y) => y, + ExprF::BinOp(NaturalTimes, x, NaturalLit(1)) => x, + ExprF::BinOp(NaturalPlus, NaturalLit(x), NaturalLit(y)) => { + NaturalLit(x + y) } - BinOp(NaturalTimes, NaturalLit(x), NaturalLit(y)) => { - Done(NaturalLit(x * y)) + ExprF::BinOp(NaturalTimes, NaturalLit(x), NaturalLit(y)) => { + NaturalLit(x * y) } - BinOp(TextAppend, TextLit(x), TextLit(y)) => Done(TextLit(x + y)), - BinOp(ListAppend, EmptyListLit(_), y) => DoneRef(y), - BinOp(ListAppend, x, EmptyListLit(_)) => DoneRef(x), - BinOp(ListAppend, NEListLit(xs), NEListLit(ys)) => { - let xs = xs.iter().cloned(); - let ys = ys.iter().cloned(); - Done(NEListLit(xs.chain(ys).collect())) + + ExprF::BinOp(ListAppend, EmptyListLit(_), y) => y, + ExprF::BinOp(ListAppend, x, EmptyListLit(_)) => x, + ExprF::BinOp(ListAppend, NEListLit(mut xs), NEListLit(mut ys)) => { + xs.append(&mut ys); + NEListLit(xs) } - Merge(RecordLit(handlers), UnionLit(l, v, _), _) => { - match handlers.get(&l) { - Some(h) => Continue(App(h.clone(), vec![v.clone()])), - None => DoneAsIs, - } + ExprF::BinOp(TextAppend, TextLit(mut x), TextLit(mut y)) => { + x.append(&mut y); + TextLit(x) } - Merge(RecordLit(handlers), UnionConstructor(l, _), _) => { - match handlers.get(&l) { - Some(h) => DoneRefSub(h), - None => DoneAsIs, + ExprF::BinOp(TextAppend, TextLit(x), y) if x.is_empty() => y, + ExprF::BinOp(TextAppend, x, TextLit(y)) if y.is_empty() => x, + + ExprF::Field(UnionType(ctx, kts), l) => UnionConstructor(ctx, l, kts), + ExprF::Field(RecordLit(mut kvs), l) => match kvs.remove(&l) { + Some(r) => r.normalize(), + None => { + // Couldn't do anything useful, so just normalize subexpressions + Expr(rc(ExprF::Field(RecordLit(kvs).normalize_to_expr(), l))) } - } - Field(RecordLit(kvs), l) => match kvs.get(&l) { - Some(r) => DoneRefSub(r), - None => DoneAsIs, }, - Field(UnionType(kts), l) => { - Done(UnionConstructor(l.clone(), kts.clone())) + ExprF::Projection(_, ls) if ls.is_empty() => { + RecordLit(std::collections::BTreeMap::new()) } - Projection(_, ls) if ls.is_empty() => { - Done(RecordLit(std::collections::BTreeMap::new())) - } - Projection(RecordLit(kvs), ls) => Done(RecordLit( - ls.iter() - .filter_map(|l| kvs.get(l).map(|x| (l.clone(), x.clone()))) + ExprF::Projection(RecordLit(mut kvs), ls) => RecordLit( + ls.into_iter() + .filter_map(|l| kvs.remove(&l).map(|x| (l, x))) .collect(), - )), - Embed(e) => DoneRefSub(&e.0), - _ => DoneAsIs, - }; - - match what_next { - Continue(e) => normalize_ref(&e.embed_absurd()), - ContinueSub(e) => normalize_ref(e.embed_absurd().as_ref()), - Done(e) => e, - DoneRef(e) => e.clone(), - DoneRefSub(e) => e.unroll(), - DoneAsIs => expr.map_ref_simple(ExprF::roll).map_ref( - SubExpr::clone, - X::clone, - |_| unreachable!(), - Label::clone, ), + ExprF::Merge(RecordLit(mut handlers), e, t) => { + let e = match e { + UnionConstructor(ctor_ctx, l, kts) => match handlers.remove(&l) + { + Some(h) => return h.normalize(), + None => UnionConstructor(ctor_ctx, l, kts), + }, + UnionLit(l, v, (kts_ctx, kts)) => match handlers.remove(&l) { + Some(h) => { + let h = h.normalize(); + let v = v.normalize(); + return h.app(v); + } + None => UnionLit(l, v, (kts_ctx, kts)), + }, + e => e, + }; + // Couldn't do anything useful, so just normalize subexpressions + Expr(rc(ExprF::Merge( + RecordLit(handlers).normalize_to_expr(), + e.normalize_to_expr(), + t.map(WHNF::normalize_to_expr), + ))) + } + // Couldn't do anything useful, so just normalize subexpressions + expr => { + Expr(rc(expr.map_ref_simple(|e| e.clone().normalize_to_expr()))) + } } } @@ -348,8 +797,8 @@ fn normalize_ref(expr: &Expr<X, Normalized<'static>>) -> Expr<X, X> { /// However, `normalize` will not fail if the expression is ill-typed and will /// leave ill-typed sub-expressions unevaluated. /// -fn normalize(e: SubExpr<X, Normalized<'static>>) -> SubExpr<X, X> { - normalize_ref(e.as_ref()).roll() +fn normalize(e: InputSubExpr) -> OutputSubExpr { + normalize_whnf(NormalizationContext::new(), e).normalize_to_expr() } #[cfg(test)] @@ -489,7 +938,7 @@ mod spec_tests { norm!(success_prelude_Optional_unzip_1, "prelude/Optional/unzip/1"); norm!(success_prelude_Text_concat_0, "prelude/Text/concat/0"); norm!(success_prelude_Text_concat_1, "prelude/Text/concat/1"); - // norm!(success_prelude_Text_concatMap_0, "prelude/Text/concatMap/0"); + norm!(success_prelude_Text_concatMap_0, "prelude/Text/concatMap/0"); norm!(success_prelude_Text_concatMap_1, "prelude/Text/concatMap/1"); // norm!(success_prelude_Text_concatMapSep_0, "prelude/Text/concatMapSep/0"); // norm!(success_prelude_Text_concatMapSep_1, "prelude/Text/concatMapSep/1"); @@ -536,7 +985,7 @@ mod spec_tests { // norm!(success_unit_IfAlternativesIdentical, "unit/IfAlternativesIdentical"); norm!(success_unit_IfFalse, "unit/IfFalse"); norm!(success_unit_IfNormalizePredicateAndBranches, "unit/IfNormalizePredicateAndBranches"); - // norm!(success_unit_IfTrivial, "unit/IfTrivial"); + norm!(success_unit_IfTrivial, "unit/IfTrivial"); norm!(success_unit_IfTrue, "unit/IfTrue"); norm!(success_unit_Integer, "unit/Integer"); norm!(success_unit_IntegerNegative, "unit/IntegerNegative"); @@ -603,42 +1052,42 @@ mod spec_tests { norm!(success_unit_None, "unit/None"); norm!(success_unit_NoneNatural, "unit/NoneNatural"); // norm!(success_unit_OperatorAndEquivalentArguments, "unit/OperatorAndEquivalentArguments"); - // norm!(success_unit_OperatorAndLhsFalse, "unit/OperatorAndLhsFalse"); - // norm!(success_unit_OperatorAndLhsTrue, "unit/OperatorAndLhsTrue"); - // norm!(success_unit_OperatorAndNormalizeArguments, "unit/OperatorAndNormalizeArguments"); - // norm!(success_unit_OperatorAndRhsFalse, "unit/OperatorAndRhsFalse"); - // norm!(success_unit_OperatorAndRhsTrue, "unit/OperatorAndRhsTrue"); + norm!(success_unit_OperatorAndLhsFalse, "unit/OperatorAndLhsFalse"); + norm!(success_unit_OperatorAndLhsTrue, "unit/OperatorAndLhsTrue"); + norm!(success_unit_OperatorAndNormalizeArguments, "unit/OperatorAndNormalizeArguments"); + norm!(success_unit_OperatorAndRhsFalse, "unit/OperatorAndRhsFalse"); + norm!(success_unit_OperatorAndRhsTrue, "unit/OperatorAndRhsTrue"); // norm!(success_unit_OperatorEqualEquivalentArguments, "unit/OperatorEqualEquivalentArguments"); - // norm!(success_unit_OperatorEqualLhsTrue, "unit/OperatorEqualLhsTrue"); - // norm!(success_unit_OperatorEqualNormalizeArguments, "unit/OperatorEqualNormalizeArguments"); - // norm!(success_unit_OperatorEqualRhsTrue, "unit/OperatorEqualRhsTrue"); + norm!(success_unit_OperatorEqualLhsTrue, "unit/OperatorEqualLhsTrue"); + norm!(success_unit_OperatorEqualNormalizeArguments, "unit/OperatorEqualNormalizeArguments"); + norm!(success_unit_OperatorEqualRhsTrue, "unit/OperatorEqualRhsTrue"); norm!(success_unit_OperatorListConcatenateLhsEmpty, "unit/OperatorListConcatenateLhsEmpty"); norm!(success_unit_OperatorListConcatenateListList, "unit/OperatorListConcatenateListList"); norm!(success_unit_OperatorListConcatenateNormalizeArguments, "unit/OperatorListConcatenateNormalizeArguments"); norm!(success_unit_OperatorListConcatenateRhsEmpty, "unit/OperatorListConcatenateRhsEmpty"); // norm!(success_unit_OperatorNotEqualEquivalentArguments, "unit/OperatorNotEqualEquivalentArguments"); - // norm!(success_unit_OperatorNotEqualLhsFalse, "unit/OperatorNotEqualLhsFalse"); - // norm!(success_unit_OperatorNotEqualNormalizeArguments, "unit/OperatorNotEqualNormalizeArguments"); - // norm!(success_unit_OperatorNotEqualRhsFalse, "unit/OperatorNotEqualRhsFalse"); + norm!(success_unit_OperatorNotEqualLhsFalse, "unit/OperatorNotEqualLhsFalse"); + norm!(success_unit_OperatorNotEqualNormalizeArguments, "unit/OperatorNotEqualNormalizeArguments"); + norm!(success_unit_OperatorNotEqualRhsFalse, "unit/OperatorNotEqualRhsFalse"); // norm!(success_unit_OperatorOrEquivalentArguments, "unit/OperatorOrEquivalentArguments"); - // norm!(success_unit_OperatorOrLhsFalse, "unit/OperatorOrLhsFalse"); - // norm!(success_unit_OperatorOrLhsTrue, "unit/OperatorOrLhsTrue"); - // norm!(success_unit_OperatorOrNormalizeArguments, "unit/OperatorOrNormalizeArguments"); - // norm!(success_unit_OperatorOrRhsFalse, "unit/OperatorOrRhsFalse"); - // norm!(success_unit_OperatorOrRhsTrue, "unit/OperatorOrRhsTrue"); - // norm!(success_unit_OperatorPlusLhsZero, "unit/OperatorPlusLhsZero"); - // norm!(success_unit_OperatorPlusNormalizeArguments, "unit/OperatorPlusNormalizeArguments"); + norm!(success_unit_OperatorOrLhsFalse, "unit/OperatorOrLhsFalse"); + norm!(success_unit_OperatorOrLhsTrue, "unit/OperatorOrLhsTrue"); + norm!(success_unit_OperatorOrNormalizeArguments, "unit/OperatorOrNormalizeArguments"); + norm!(success_unit_OperatorOrRhsFalse, "unit/OperatorOrRhsFalse"); + norm!(success_unit_OperatorOrRhsTrue, "unit/OperatorOrRhsTrue"); + norm!(success_unit_OperatorPlusLhsZero, "unit/OperatorPlusLhsZero"); + norm!(success_unit_OperatorPlusNormalizeArguments, "unit/OperatorPlusNormalizeArguments"); norm!(success_unit_OperatorPlusOneAndOne, "unit/OperatorPlusOneAndOne"); - // norm!(success_unit_OperatorPlusRhsZero, "unit/OperatorPlusRhsZero"); - // norm!(success_unit_OperatorTextConcatenateLhsEmpty, "unit/OperatorTextConcatenateLhsEmpty"); - // norm!(success_unit_OperatorTextConcatenateNormalizeArguments, "unit/OperatorTextConcatenateNormalizeArguments"); - // norm!(success_unit_OperatorTextConcatenateRhsEmpty, "unit/OperatorTextConcatenateRhsEmpty"); + norm!(success_unit_OperatorPlusRhsZero, "unit/OperatorPlusRhsZero"); + norm!(success_unit_OperatorTextConcatenateLhsEmpty, "unit/OperatorTextConcatenateLhsEmpty"); + norm!(success_unit_OperatorTextConcatenateNormalizeArguments, "unit/OperatorTextConcatenateNormalizeArguments"); + norm!(success_unit_OperatorTextConcatenateRhsEmpty, "unit/OperatorTextConcatenateRhsEmpty"); norm!(success_unit_OperatorTextConcatenateTextText, "unit/OperatorTextConcatenateTextText"); - // norm!(success_unit_OperatorTimesLhsOne, "unit/OperatorTimesLhsOne"); - // norm!(success_unit_OperatorTimesLhsZero, "unit/OperatorTimesLhsZero"); - // norm!(success_unit_OperatorTimesNormalizeArguments, "unit/OperatorTimesNormalizeArguments"); - // norm!(success_unit_OperatorTimesRhsOne, "unit/OperatorTimesRhsOne"); - // norm!(success_unit_OperatorTimesRhsZero, "unit/OperatorTimesRhsZero"); + norm!(success_unit_OperatorTimesLhsOne, "unit/OperatorTimesLhsOne"); + norm!(success_unit_OperatorTimesLhsZero, "unit/OperatorTimesLhsZero"); + norm!(success_unit_OperatorTimesNormalizeArguments, "unit/OperatorTimesNormalizeArguments"); + norm!(success_unit_OperatorTimesRhsOne, "unit/OperatorTimesRhsOne"); + norm!(success_unit_OperatorTimesRhsZero, "unit/OperatorTimesRhsZero"); norm!(success_unit_OperatorTimesTwoAndTwo, "unit/OperatorTimesTwoAndTwo"); norm!(success_unit_Optional, "unit/Optional"); norm!(success_unit_OptionalBuild, "unit/OptionalBuild"); @@ -675,7 +1124,7 @@ mod spec_tests { norm!(success_unit_SomeNormalizeArguments, "unit/SomeNormalizeArguments"); norm!(success_unit_Sort, "unit/Sort"); norm!(success_unit_Text, "unit/Text"); - // norm!(success_unit_TextInterpolate, "unit/TextInterpolate"); + norm!(success_unit_TextInterpolate, "unit/TextInterpolate"); norm!(success_unit_TextLiteral, "unit/TextLiteral"); norm!(success_unit_TextNormalizeInterpolations, "unit/TextNormalizeInterpolations"); norm!(success_unit_TextShow, "unit/TextShow"); diff --git a/dhall/src/typecheck.rs b/dhall/src/typecheck.rs index 5aaeb08..b26f845 100644 --- a/dhall/src/typecheck.rs +++ b/dhall/src/typecheck.rs @@ -44,9 +44,9 @@ impl<'a> Normalized<'a> { fn unroll_ref(&self) -> &Expr<X, X> { self.as_expr().as_ref() } - fn shift(&self, delta: isize, var: &V<Label>) -> Self { + fn shift0(&self, delta: isize, label: &Label) -> Self { // shift the type too ? - Normalized(shift(delta, var, &self.0), self.1.clone(), self.2) + Normalized(shift0(delta, label, &self.0), self.1.clone(), self.2) } } impl Normalized<'static> { @@ -86,10 +86,10 @@ impl<'a> Type<'a> { Cow::Owned(e) => Ok(Cow::Owned(e.into_expr().unroll())), } } - fn shift(&self, delta: isize, var: &V<Label>) -> Self { + fn shift0(&self, delta: isize, label: &Label) -> Self { use TypeInternal::*; Type(match &self.0 { - Expr(e) => Expr(Box::new(e.shift(delta, var))), + Expr(e) => Expr(Box::new(e.shift0(delta, label))), Const(c) => Const(*c), SuperType => SuperType, }) @@ -168,11 +168,7 @@ where eq2 } } - (App(fL, aL), App(fR, aR)) => { - go(ctx, fL, fR) - && aL.len() == aR.len() - && aL.iter().zip(aR.iter()).all(|(aL, aR)| go(ctx, aL, aR)) - } + (App(fL, aL), App(fR, aR)) => go(ctx, fL, fR) && go(ctx, aL, aR), (RecordType(ktsL0), RecordType(ktsR0)) => { ktsL0.len() == ktsR0.len() && ktsL0 @@ -378,9 +374,8 @@ fn type_with( let ret = match e.as_ref() { Lam(x, t, b) => { let t = mktype(ctx, t.clone())?; - let ctx2 = ctx - .insert(x.clone(), t.clone()) - .map(|e| e.shift(1, &V(x.clone(), 0))); + let ctx2 = + ctx.insert(x.clone(), t.clone()).map(|_, e| e.shift0(1, x)); let b = type_with(&ctx2, b.clone())?; Ok(RetExpr(Pi( x.clone(), @@ -395,9 +390,8 @@ fn type_with( mkerr(InvalidInputType(ta.into_normalized()?)), ); - let ctx2 = ctx - .insert(x.clone(), ta.clone()) - .map(|e| e.shift(1, &V(x.clone(), 0))); + let ctx2 = + ctx.insert(x.clone(), ta.clone()).map(|_, e| e.shift0(1, x)); let tb = type_with(&ctx2, tb.clone())?; let kB = ensure_is_const!( &tb.get_type()?, @@ -476,46 +470,22 @@ fn type_last_layer( Some(e) => Ok(RetType(e.clone())), None => Err(mkerr(UnboundVariable)), }, - App(f, args) => { - let mut tf = f.get_type()?.into_owned(); - // Reconstruct the application `f a0 a1 ...` - // for error reporting - let mkf = |args: Vec<_>, i| { - rc(App( - f.into_expr(), - args.into_iter().take(i).map(Typed::into_expr).collect(), - )) - }; - - for (i, a) in args.iter().enumerate() { - let (x, tx, tb) = ensure_matches!(tf, - Pi(x, tx, tb) => (x, tx, tb), - mkerr(NotAFunction(Typed( - mkf(args, i), - Some(tf), - PhantomData - ))) - ); - let tx = mktype(ctx, tx.embed_absurd())?; - ensure_equal!(&tx, a.get_type()?, { - let a = a.clone(); - mkerr(TypeMismatch( - Typed(mkf(args, i + 1), Some(tf), PhantomData), - tx.into_normalized()?, - a, - )) - }); - tf = mktype( - ctx, - rc(Let( - x.clone(), - None, - a.clone().normalize().embed(), - tb.embed_absurd(), - )), - )?; - } - Ok(RetType(tf)) + App(f, a) => { + let tf = f.get_type()?; + let (x, tx, tb) = ensure_matches!(tf, + Pi(x, tx, tb) => (x, tx, tb), + mkerr(NotAFunction(f)) + ); + let tx = mktype(ctx, tx.embed_absurd())?; + ensure_equal!(a.get_type()?, &tx, { + mkerr(TypeMismatch(f, tx.into_normalized()?, a)) + }); + Ok(RetExpr(Let( + x.clone(), + None, + a.normalize().embed(), + tb.embed_absurd(), + ))) } Annot(x, t) => { let t = t.normalize().into_type(); @@ -593,13 +563,7 @@ fn type_last_layer( let e = dhall::subexpr!(Some x : Optional t); Ok(RetType(type_with(ctx, e)?.get_type()?.into_owned())) } - EmptyOptionalLit(t) => { - let t = t.normalize(); - ensure_simple_type!(t, mkerr(InvalidOptionalType(t))); - let t = t.embed(); - Ok(RetExpr(dhall::expr!(Optional t))) - } - NEOptionalLit(x) => { + SomeLit(x) => { let tx = x.get_type_move()?; ensure_simple_type!( tx, @@ -706,7 +670,7 @@ fn type_last_layer( TextLit(_) => Ok(RetType(simple_type_from_builtin(Text))), BinOp(o @ ListAppend, l, r) => { match l.get_type()?.unroll_ref()?.as_ref() { - App(f, args) if args.len() == 1 => match f.as_ref() { + App(f, _) => match f.as_ref() { Builtin(List) => {} _ => return Err(mkerr(BinOpTypeMismatch(o, l))), }, |