diff options
Diffstat (limited to 'dhall')
| -rw-r--r-- | dhall/src/error/mod.rs | 2 | ||||
| -rw-r--r-- | dhall/src/phase/typecheck.rs | 68 |
2 files changed, 17 insertions, 53 deletions
diff --git a/dhall/src/error/mod.rs b/dhall/src/error/mod.rs index 3445768..13a9d7e 100644 --- a/dhall/src/error/mod.rs +++ b/dhall/src/error/mod.rs @@ -79,10 +79,8 @@ pub(crate) enum TypeMessage { ProjectionMustBeRecord, ProjectionMissingEntry, Sort, - RecordMismatch(Value, Value), RecordTypeDuplicateField, RecordTypeMergeRequiresRecordType(Value), - RecordTypeMismatch(Value, Value, Value, Value), UnionTypeDuplicateField, EquivalenceArgumentMustBeTerm(bool, Value), EquivalenceTypeMismatch(Value, Value), diff --git a/dhall/src/phase/typecheck.rs b/dhall/src/phase/typecheck.rs index 77ef689..8a3b43a 100644 --- a/dhall/src/phase/typecheck.rs +++ b/dhall/src/phase/typecheck.rs @@ -1,3 +1,4 @@ +use std::cmp::max; use std::collections::HashMap; use dhall_syntax::{ @@ -50,15 +51,16 @@ fn tck_record_type( use crate::error::TypeMessage::*; use std::collections::hash_map::Entry; let mut new_kts = HashMap::new(); - // Check that all types are the same const - let mut k = None; + // An empty record type has type Type + let mut k = Const::Type; for e in kts { let (x, t) = e?; - 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))), + // 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(_) => { @@ -67,8 +69,6 @@ fn tck_record_type( Entry::Vacant(_) => entry.or_insert_with(|| t), }; } - // An empty record type has type Type - let k = k.unwrap_or(Const::Type); Ok(Value::from_valuef_and_type( ValueF::RecordType(new_kts), @@ -122,7 +122,6 @@ where } fn function_check(a: Const, b: Const) -> Const { - use std::cmp::max; if b == Const::Type { Const::Type } else { @@ -546,16 +545,7 @@ fn type_last_layer( use crate::phase::normalize::merge_maps; let l_type = l.get_type()?; - let l_kind = l_type.get_type()?; let r_type = r.get_type()?; - let r_kind = r_type.get_type()?; - - // Check the equality of kinds. - // This is to disallow expression such as: - // "{ x = Text } // { y = 1 }" - if l_kind != r_kind { - return mkerr(RecordMismatch(l.clone(), r.clone())); - } // Extract the LHS record type let l_type_borrow = l_type.as_whnf(); @@ -581,28 +571,14 @@ fn type_last_layer( kts.into_iter().map(|(x, v)| Ok((x.clone(), v))), )?) } - BinOp(RecursiveRecordMerge, l, r) => { - let l_type = l.get_type()?; - let l_kind = l_type.get_type()?; - let r_type = r.get_type()?; - let r_kind = r_type.get_type()?; - - // Check the equality of kinds. - // This is to disallow expression such as: - // "{ x = Text } // { y = 1 }" - if l_kind != r_kind { - return mkerr(RecordMismatch(l.clone(), r.clone())); - } - - RetTypeOnly(type_last_layer( - ctx, - ExprF::BinOp( - RecursiveRecordTypeMerge, - l_type.into_owned(), - r_type.into_owned(), - ), - )?) - } + BinOp(RecursiveRecordMerge, l, r) => RetTypeOnly(type_last_layer( + ctx, + ExprF::BinOp( + RecursiveRecordTypeMerge, + l.get_type()?.into_owned(), + r.get_type()?.into_owned(), + ), + )?), BinOp(RecursiveRecordTypeMerge, l, r) => { use crate::phase::normalize::intersection_with_key; @@ -622,17 +598,7 @@ fn type_last_layer( } }; - // Const values must match for the Records - let k = if k_l == k_r { - k_l - } else { - return mkerr(RecordTypeMismatch( - Value::from_const(k_l), - Value::from_const(k_r), - l.clone(), - r.clone(), - )); - }; + let k = max(k_l, k_r); // Extract the LHS record type let borrow_l = l.as_whnf(); |