From 071ba528cd8c6a222be345ddec7560bb45cca6be Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Thu, 8 Aug 2019 19:33:07 +0200 Subject: Add support for dependent types --- dhall/src/phase/binary.rs | 7 ++++++ dhall/src/phase/normalize.rs | 12 ++++++--- dhall/src/phase/typecheck.rs | 60 +++++++++++++++++++++++++++++--------------- 3 files changed, 56 insertions(+), 23 deletions(-) (limited to 'dhall/src/phase') diff --git a/dhall/src/phase/binary.rs b/dhall/src/phase/binary.rs index 5e7eb40..719b1c7 100644 --- a/dhall/src/phase/binary.rs +++ b/dhall/src/phase/binary.rs @@ -119,6 +119,7 @@ fn cbor_value_to_dhall( 9 => RightBiasedRecordMerge, 10 => RecursiveRecordTypeMerge, 11 => ImportAlt, + 12 => Equivalence, _ => { Err(DecodeError::WrongFormatError("binop".to_owned()))? } @@ -211,6 +212,10 @@ fn cbor_value_to_dhall( .collect::>()?, ))) } + [U64(19), t] => { + let t = cbor_value_to_dhall(&t)?; + Assert(t) + } [U64(24), hash, U64(mode), U64(scheme), rest..] => { let mode = match mode { 0 => ImportMode::Code, @@ -504,6 +509,7 @@ where ) } Annot(x, y) => ser_seq!(ser; tag(26), expr(x), expr(y)), + Assert(x) => ser_seq!(ser; tag(19), expr(x)), SomeLit(x) => ser_seq!(ser; tag(5), null(), expr(x)), EmptyListLit(x) => match x.as_ref() { App(f, a) => match f.as_ref() { @@ -541,6 +547,7 @@ where RightBiasedRecordMerge => 9, RecursiveRecordTypeMerge => 10, ImportAlt => 11, + Equivalence => 12, }; ser_seq!(ser; tag(3), U64(op), expr(x), expr(y)) } diff --git a/dhall/src/phase/normalize.rs b/dhall/src/phase/normalize.rs index 395cf28..ecad063 100644 --- a/dhall/src/phase/normalize.rs +++ b/dhall/src/phase/normalize.rs @@ -508,9 +508,9 @@ where fn apply_binop<'a>(o: BinOp, x: &'a Thunk, y: &'a Thunk) -> Option> { use BinOp::{ - BoolAnd, BoolEQ, BoolNE, BoolOr, ListAppend, NaturalPlus, NaturalTimes, - RecursiveRecordMerge, RecursiveRecordTypeMerge, RightBiasedRecordMerge, - TextAppend, + BoolAnd, BoolEQ, BoolNE, BoolOr, Equivalence, ListAppend, NaturalPlus, + NaturalTimes, RecursiveRecordMerge, RecursiveRecordTypeMerge, + RightBiasedRecordMerge, TextAppend, }; use Value::{ BoolLit, EmptyListLit, NEListLit, NaturalLit, RecordLit, RecordType, @@ -626,6 +626,11 @@ fn apply_binop<'a>(o: BinOp, x: &'a Thunk, y: &'a Thunk) -> Option> { Ret::Value(RecordType(kvs)) } + (Equivalence, _, _) => Ret::Value(Value::Equivalence( + TypeThunk::from_thunk(x.clone()), + TypeThunk::from_thunk(y.clone()), + )), + _ => return None, }) } @@ -641,6 +646,7 @@ pub fn normalize_one_layer(expr: ExprF) -> Value { ExprF::Embed(_) => unreachable!(), ExprF::Var(_) => unreachable!(), ExprF::Annot(x, _) => Ret::Thunk(x), + ExprF::Assert(_) => Ret::Expr(expr), ExprF::Lam(x, t, e) => { Ret::Value(Lam(x.into(), TypeThunk::from_thunk(t), e)) } diff --git a/dhall/src/phase/typecheck.rs b/dhall/src/phase/typecheck.rs index 2e4642c..297a096 100644 --- a/dhall/src/phase/typecheck.rs +++ b/dhall/src/phase/typecheck.rs @@ -60,18 +60,7 @@ fn tck_pi_type( } }; - let k = match function_check(ka, kb) { - Ok(k) => k, - Err(()) => { - return Err(TypeError::new( - ctx, - NoDependentTypes( - tx.to_normalized(), - te.get_type()?.to_normalized(), - ), - )) - } - }; + let k = function_check(ka, kb); Ok(Typed::from_thunk_and_type( Value::Pi(x.into(), TypeThunk::from_type(tx), TypeThunk::from_type(te)) @@ -164,14 +153,13 @@ fn tck_union_type( )) } -fn function_check(a: Const, b: Const) -> Result { - use dhall_syntax::Const::*; - match (a, b) { - (_, Type) => Ok(Type), - (Kind, Kind) => Ok(Kind), - (Sort, Sort) => Ok(Sort), - (Sort, Kind) => Ok(Sort), - _ => Err(()), +fn function_check(a: Const, b: Const) -> Const { + use dhall_syntax::Const::Type; + use std::cmp::max; + if b == Type { + Type + } else { + max(a, b) } } @@ -403,6 +391,19 @@ fn type_last_layer( ); Ok(RetTypeOnly(x.get_type()?.into_owned())) } + Assert(t) => { + match t.to_value() { + Value::Equivalence(x, y) if x == y => {} + Value::Equivalence(x, y) => { + return Err(mkerr(AssertMismatch( + x.to_typed(), + y.to_typed(), + ))) + } + _ => return Err(mkerr(AssertMustTakeEquivalence)), + } + Ok(RetTypeOnly(t.to_type())) + } BoolIf(x, y, z) => { ensure_equal!( x.get_type()?, @@ -807,6 +808,24 @@ fn type_last_layer( Ok(RetTypeOnly(l.get_type()?.into_owned())) } + BinOp(Equivalence, l, r) => { + ensure_simple_type!( + l.get_type()?, + mkerr(EquivalenceArgumentMustBeTerm(true, l.clone())), + ); + ensure_simple_type!( + r.get_type()?, + mkerr(EquivalenceArgumentMustBeTerm(false, r.clone())), + ); + + ensure_equal!( + l.get_type()?, + r.get_type()?, + mkerr(EquivalenceTypeMismatch(r.clone(), l.clone())) + ); + + Ok(RetTypeOnly(Type::from_const(dhall_syntax::Const::Type))) + } BinOp(o, l, r) => { let t = builtin_to_type(match o { BoolAnd => Bool, @@ -821,6 +840,7 @@ fn type_last_layer( RecursiveRecordMerge => unreachable!(), RecursiveRecordTypeMerge => unreachable!(), ImportAlt => unreachable!("There should remain no import alternatives in a resolved expression"), + Equivalence => unreachable!(), })?; ensure_equal!( -- cgit v1.2.3