language-servers/roc
1
0
Fork 0
mirror of https://github.com/roc-lang/roc.git synced 2025-10-02 00:01:16 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 6

finetuning some comments

Browse source
This commit is contained in:
Folkert 2022-04-24 13:50:47 +02:00
parent dbae805071
commit cf89dd7f84
No known key found for this signature in database
GPG key ID: 1F17F6FFD112B97C
1 changed files with 13 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

25
compiler/can/src/def.rs
View file

@ -1953,10 +1953,12 @@ fn correct_mutual_recursive_type_alias<'a>(
// Don't try to instantiate the alias itself in its definition. // Don't try to instantiate the alias itself in its definition.
to_instantiate_bitvec.set(index, false); to_instantiate_bitvec.set(index, false);
// now we do something sneaky. In `can_instantiate_symbol` we want to be able to // we run into a problem here where we want to modify an element in the aliases array,
// take a reference to an `Alias` in the `aliases` vec. That would not work if // but also reference the other elements. The borrow checker, correctly, says no to that.
// we also had a mutable reference to an alias in that vec. So we swap out the //
// type. // So we get creative: we swap out the element we want to modify with a dummy. We can
// then freely modify the type we moved out, and the `to_instantiate_bitvec` mask
// prevents our dummy from being used.
let alias_region = aliases[index].region; let alias_region = aliases[index].region;
let mut alias_type = Type::EmptyRec; let mut alias_type = Type::EmptyRec;
@ -1981,13 +1983,12 @@ fn correct_mutual_recursive_type_alias<'a>(
// We can instantiate this alias in future iterations // We can instantiate this alias in future iterations
to_instantiate_bitvec.set(index, true); to_instantiate_bitvec.set(index, true);
let alias = &mut aliases[index]; // add any lambda sets that the instantiation created to the current alias
aliases[index].lambda_set_variables.extend(
for lambda_set_var in new_lambda_sets { new_lambda_sets
alias .iter()
.lambda_set_variables .map(|var| LambdaSet(Type::Variable(*var))),
.push(LambdaSet(Type::Variable(lambda_set_var))); );
}
// Now mark the alias recursive, if it needs to be. // Now mark the alias recursive, if it needs to be.
let rec = symbols_introduced[index]; let rec = symbols_introduced[index];
@ -1998,7 +1999,7 @@ fn correct_mutual_recursive_type_alias<'a>(
let _made_recursive = make_tag_union_of_alias_recursive( let _made_recursive = make_tag_union_of_alias_recursive(
env, env,
rec, rec,
alias, &mut aliases[index],
vec![], vec![],
var_store, var_store,
&mut can_still_report_error, &mut can_still_report_error,