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authorNadrieril2020-01-25 13:29:27 +0000
committerNadrieril2020-01-25 13:29:27 +0000
commit8c64ae33149db4edaaa89d2d187baf10a2b9f8bf (patch)
tree1e2cf38f35594ceeba34f3650d68b42792e0c64d /dhall/src/semantics/phase
parentf2e8c414993d5c9fcc63f5c035f755712c01dad0 (diff)
Make most type errors stringy
Diffstat (limited to 'dhall/src/semantics/phase')
-rw-r--r--dhall/src/semantics/phase/typecheck.rs151
1 files changed, 53 insertions, 98 deletions
diff --git a/dhall/src/semantics/phase/typecheck.rs b/dhall/src/semantics/phase/typecheck.rs
index 0f3754e..44678cd 100644
--- a/dhall/src/semantics/phase/typecheck.rs
+++ b/dhall/src/semantics/phase/typecheck.rs
@@ -357,8 +357,8 @@ fn type_last_layer(
use syntax::Builtin::*;
use syntax::Const::Type;
use syntax::ExprKind::*;
- use TypeMessage::*;
- let mkerr = |msg: TypeMessage| Err(TypeError::new(msg));
+ let mkerr =
+ |msg: &str| Err(TypeError::new(TypeMessage::Custom(msg.to_string())));
/// Intermediary return type
enum Ret {
@@ -381,10 +381,10 @@ fn type_last_layer(
let tf_borrow = tf.as_whnf();
let (tx, tb) = match &*tf_borrow {
ValueKind::Pi(_, tx, tb) => (tx, tb),
- _ => return mkerr(NotAFunction(f.clone())),
+ _ => return mkerr("NotAFunction"),
};
if &a.get_type()? != tx {
- return mkerr(TypeMismatch(f.clone(), tx.clone(), a.clone()));
+ return mkerr("TypeMismatch");
}
let ret = tb.subst_shift(&AlphaVar::default(), a);
@@ -393,35 +393,33 @@ fn type_last_layer(
}
Annot(x, t) => {
if &x.get_type()? != t {
- return mkerr(AnnotMismatch(x.clone(), t.clone()));
+ return mkerr("AnnotMismatch");
}
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),
+ ValueKind::Equivalence(..) => return mkerr("AssertMismatch"),
+ _ => 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()));
+ return mkerr("InvalidPredicate");
}
if y.get_type()?.get_type()?.as_const() != Some(Type) {
- return mkerr(IfBranchMustBeTerm(true, y.clone()));
+ return mkerr("IfBranchMustBeTerm");
}
if z.get_type()?.get_type()?.as_const() != Some(Type) {
- return mkerr(IfBranchMustBeTerm(false, z.clone()));
+ return mkerr("IfBranchMustBeTerm");
}
if y.get_type()? != z.get_type()? {
- return mkerr(IfBranchMismatch(y.clone(), z.clone()));
+ return mkerr("IfBranchMismatch");
}
RetTypeOnly(y.get_type()?)
@@ -433,7 +431,7 @@ fn type_last_layer(
{
args[0].clone()
}
- _ => return mkerr(InvalidListType(t.clone())),
+ _ => return mkerr("InvalidListType"),
};
RetWhole(Value::from_kind_and_type(
ValueKind::EmptyListLit(arg),
@@ -443,18 +441,14 @@ fn type_last_layer(
NEListLit(xs) => {
let mut iter = xs.iter().enumerate();
let (_, x) = iter.next().unwrap();
- for (i, y) in iter {
+ for (_, y) in iter {
if x.get_type()? != y.get_type()? {
- return mkerr(InvalidListElement(
- i,
- x.get_type()?,
- y.clone(),
- ));
+ return mkerr("InvalidListElement");
}
}
let t = x.get_type()?;
if t.get_type()?.as_const() != Some(Type) {
- return mkerr(InvalidListType(t));
+ return mkerr("InvalidListType");
}
RetTypeOnly(Value::from_builtin(syntax::Builtin::List).app(t))
@@ -462,7 +456,7 @@ fn type_last_layer(
SomeLit(x) => {
let t = x.get_type()?;
if t.get_type()?.as_const() != Some(Type) {
- return mkerr(InvalidOptionalType(t));
+ return mkerr("InvalidOptionalType");
}
RetTypeOnly(Value::from_builtin(syntax::Builtin::Optional).app(t))
@@ -479,48 +473,25 @@ fn type_last_layer(
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())),
+ Some(tth) => RetTypeOnly(tth.clone()),
+ None => return mkerr("MissingRecordField"),
},
// 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.new_binder(x),
- t.clone(),
- r.under_binder(),
- )?
- )
- },
- Some(None) => {
- RetTypeOnly(r.clone())
- },
- None => {
- return mkerr(MissingUnionField(
- x.clone(),
- r.clone(),
- ))
- },
- },
- _ => {
- return mkerr(NotARecord(
- x.clone(),
- r.clone()
- ))
+ Some(Some(t)) => RetTypeOnly(tck_pi_type(
+ ctx.new_binder(x),
+ t.clone(),
+ r.under_binder(),
+ )?),
+ Some(None) => RetTypeOnly(r.clone()),
+ None => return mkerr("MissingUnionField"),
},
+ _ => return mkerr("NotARecord"),
}
- }
- // _ => mkerr(NotARecord(
- // x,
- // r?,
- // )),
+ } // _ => mkerr("NotARecord"),
}
}
Const(c) => RetWhole(const_to_value(*c)),
@@ -535,7 +506,7 @@ fn type_last_layer(
use InterpolatedTextContents::Expr;
if let Expr(x) = contents {
if x.get_type()? != text_type {
- return mkerr(InvalidTextInterpolation(x.clone()));
+ return mkerr("InvalidTextInterpolation");
}
}
}
@@ -549,14 +520,14 @@ fn type_last_layer(
let l_type_borrow = l_type.as_whnf();
let kts_x = match &*l_type_borrow {
ValueKind::RecordType(kts) => kts,
- _ => return mkerr(MustCombineRecord(l.clone())),
+ _ => return mkerr("MustCombineRecord"),
};
// 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())),
+ _ => return mkerr("MustCombineRecord"),
};
// Union the two records, prefering
@@ -584,18 +555,14 @@ fn type_last_layer(
let borrow_l = l.as_whnf();
let kts_x = match &*borrow_l {
ValueKind::RecordType(kts) => kts,
- _ => {
- return mkerr(RecordTypeMergeRequiresRecordType(l.clone()))
- }
+ _ => return mkerr("RecordTypeMergeRequiresRecordType"),
};
// 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()))
- }
+ _ => return mkerr("RecordTypeMergeRequiresRecordType"),
};
// Ensure that the records combine without a type error
@@ -618,28 +585,28 @@ fn type_last_layer(
RetWhole(tck_record_type(kts.into_iter().map(Ok))?)
}
- BinOp(o @ ListAppend, l, r) => {
+ BinOp(ListAppend, l, r) => {
match &*l.get_type()?.as_whnf() {
ValueKind::AppliedBuiltin(List, _, _) => {}
- _ => return mkerr(BinOpTypeMismatch(*o, l.clone())),
+ _ => return mkerr("BinOpTypeMismatch"),
}
if l.get_type()? != r.get_type()? {
- return mkerr(BinOpTypeMismatch(*o, r.clone()));
+ return mkerr("BinOpTypeMismatch");
}
RetTypeOnly(l.get_type()?)
}
BinOp(Equivalence, l, r) => {
if l.get_type()?.get_type()?.as_const() != Some(Type) {
- return mkerr(EquivalenceArgumentMustBeTerm(true, l.clone()));
+ return mkerr("EquivalenceArgumentMustBeTerm");
}
if r.get_type()?.get_type()?.as_const() != Some(Type) {
- return mkerr(EquivalenceArgumentMustBeTerm(false, r.clone()));
+ return mkerr("EquivalenceArgumentMustBeTerm");
}
if l.get_type()? != r.get_type()? {
- return mkerr(EquivalenceTypeMismatch(r.clone(), l.clone()));
+ return mkerr("EquivalenceTypeMismatch");
}
RetWhole(Value::from_kind_and_type(
@@ -665,11 +632,11 @@ fn type_last_layer(
});
if l.get_type()? != t {
- return mkerr(BinOpTypeMismatch(*o, l.clone()));
+ return mkerr("BinOpTypeMismatch");
}
if r.get_type()? != t {
- return mkerr(BinOpTypeMismatch(*o, r.clone()));
+ return mkerr("BinOpTypeMismatch");
}
RetTypeOnly(t)
@@ -679,7 +646,7 @@ fn type_last_layer(
let record_borrow = record_type.as_whnf();
let handlers = match &*record_borrow {
ValueKind::RecordType(kts) => kts,
- _ => return mkerr(Merge1ArgMustBeRecord(record.clone())),
+ _ => return mkerr("Merge1ArgMustBeRecord"),
};
let union_type = union.get_type()?;
@@ -697,9 +664,7 @@ fn type_last_layer(
kts.insert("Some".into(), Some(ty.clone()));
Cow::Owned(kts)
}
- _ => {
- return mkerr(Merge2ArgMustBeUnionOrOptional(union.clone()))
- }
+ _ => return mkerr("Merge2ArgMustBeUnionOrOptional"),
};
let mut inferred_type = None;
@@ -711,19 +676,11 @@ fn type_last_layer(
let handler_type_borrow = handler_type.as_whnf();
let (tx, tb) = match &*handler_type_borrow {
ValueKind::Pi(_, tx, tb) => (tx, tb),
- _ => {
- return mkerr(NotAFunction(
- handler_type.clone(),
- ))
- }
+ _ => return mkerr("NotAFunction"),
};
if variant_type != tx {
- return mkerr(TypeMismatch(
- handler_type.clone(),
- tx.clone(),
- variant_type.clone(),
- ));
+ return mkerr("TypeMismatch");
}
// Extract `tb` from under the binder. Fails if the variable was used
@@ -731,41 +688,39 @@ fn type_last_layer(
match tb.over_binder() {
Some(x) => x,
None => return mkerr(
- MergeHandlerReturnTypeMustNotBeDependent,
+ "MergeHandlerReturnTypeMustNotBeDependent",
),
}
}
// Union alternative without type
Some(None) => handler_type.clone(),
- None => {
- return mkerr(MergeHandlerMissingVariant(x.clone()))
- }
+ None => return mkerr("MergeHandlerMissingVariant"),
};
match &inferred_type {
None => inferred_type = Some(handler_return_type),
Some(t) => {
if t != &handler_return_type {
- return mkerr(MergeHandlerTypeMismatch);
+ return mkerr("MergeHandlerTypeMismatch");
}
}
}
}
for x in variants.keys() {
if !handlers.contains_key(x) {
- return mkerr(MergeVariantMissingHandler(x.clone()));
+ return mkerr("MergeVariantMissingHandler");
}
}
match (inferred_type, type_annot.as_ref()) {
(Some(t1), Some(t2)) => {
if &t1 != t2 {
- return mkerr(MergeAnnotMismatch);
+ return mkerr("MergeAnnotMismatch");
}
RetTypeOnly(t1)
}
(Some(t), None) => RetTypeOnly(t),
(None, Some(t)) => RetTypeOnly(t.clone()),
- (None, None) => return mkerr(MergeEmptyNeedsAnnotation),
+ (None, None) => return mkerr("MergeEmptyNeedsAnnotation"),
}
}
ToMap(_, _) => unimplemented!("toMap"),
@@ -774,18 +729,18 @@ fn type_last_layer(
let record_type_borrow = record_type.as_whnf();
let kts = match &*record_type_borrow {
ValueKind::RecordType(kts) => kts,
- _ => return mkerr(ProjectionMustBeRecord),
+ _ => return mkerr("ProjectionMustBeRecord"),
};
let mut new_kts = HashMap::new();
for l in labels {
match kts.get(l) {
- None => return mkerr(ProjectionMissingEntry),
+ None => return mkerr("ProjectionMissingEntry"),
Some(t) => {
use std::collections::hash_map::Entry;
match new_kts.entry(l.clone()) {
Entry::Occupied(_) => {
- return mkerr(ProjectionDuplicateField)
+ return mkerr("ProjectionDuplicateField")
}
Entry::Vacant(e) => e.insert(t.clone()),
}