perf(check): Avoid looking through metadata when checking for an impl…

…icit type
Marwes · Aug 31, 2019 · 4a3662e · 4a3662e
1 parent d69a52e
commit 4a3662e
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Showing 5 changed files with 37 additions and 29 deletions.
diff --git a/base/src/types/mod.rs b/base/src/types/mod.rs
@@ -1012,13 +1012,17 @@ where
     }
 
     pub fn alias(name: Id, args: Vec<Generic<Id>>, typ: T) -> T {
+        Self::alias_implicit(name, args, typ, false)
+    }
+
+    pub fn alias_implicit(name: Id, args: Vec<Generic<Id>>, typ: T, is_implicit: bool) -> T {
         T::from(Type::Alias(AliasRef {
             index: 0,
             group: Arc::from(vec![AliasData {
                 name,
                 args,
                 typ,
-                is_implicit: false,
+                is_implicit,
             }]),
         }))
     }

diff --git a/check/src/implicits.rs b/check/src/implicits.rs
@@ -1,4 +1,4 @@
-use std::{cell::RefCell, convert::TryInto, fmt, rc::Rc, sync::Arc};
+use std::{convert::TryInto, fmt, rc::Rc, sync::Arc};
 
 use {itertools::Itertools, smallvec::SmallVec};
 
@@ -856,20 +856,17 @@ impl<'a> ImplicitResolver<'a> {
         metadata: Option<&'m Metadata>,
         typ: &RcType,
     ) -> Option<Option<&'m Symbol>> {
-        let has_implicit_attribute =
-            |metadata: &Metadata| metadata.get_attribute("implicit").is_some();
-        let mut is_implicit = metadata.map(&has_implicit_attribute).unwrap_or(false);
-
-        if !is_implicit {
-            // Look at the type without any implicit arguments
-            let mut iter = types::implicit_arg_iter(typ.remove_forall());
-            for _ in iter.by_ref() {}
-            is_implicit = iter
-                .typ
-                .remove_forall()
-                .applied_alias()
-                .map_or(false, |alias| alias.is_implicit());
-        }
+        // Look at the type without any implicit arguments
+        let mut iter = types::implicit_arg_iter(typ.remove_forall());
+        for _ in iter.by_ref() {}
+        let is_implicit = iter
+            .typ
+            .remove_forall()
+            .applied_alias()
+            .map_or(false, |alias| alias.is_implicit())
+            || metadata
+                .and_then(|metadata: &Metadata| metadata.get_attribute("implicit"))
+                .is_some();
 
         if is_implicit {
             Some(metadata.and_then(|m| m.definition.as_ref()))

diff --git a/check/src/typecheck.rs b/check/src/typecheck.rs
@@ -2123,6 +2123,8 @@ impl<'a> Typecheck<'a> {
             let mut alias =
                 types::translate_alias(&bind.alias.value, |typ| self.translate_ast_type(typ));
 
+            alias.is_implicit = bind.metadata.get_attribute("implicit").is_some();
+
             let replacement = self.create_unifiable_signature_with(
                 // alias.unresolved_type() is a dummy in this context
                 alias
@@ -2144,16 +2146,7 @@ impl<'a> Typecheck<'a> {
         let arc_alias_group = Alias::group(
             resolved_aliases
                 .iter()
-                .zip(
-                    bindings
-                        .iter()
-                        .map(|bind| bind.metadata.get_attribute("implicit").is_some()),
-                )
-                .map(|(a, is_implicit)| {
-                    let mut alias_data = types::translate_alias(&a, |t| self.translate_rc_type(t));
-                    alias_data.is_implicit = is_implicit;
-                    alias_data
-                })
+                .map(|a| types::translate_alias(&a, |t| self.translate_rc_type(t)))
                 .collect(),
         );
         let alias_group = self.subs.alias_group(resolved_aliases);

diff --git a/check/tests/implicits.rs b/check/tests/implicits.rs
@@ -212,7 +212,7 @@ f (Test ())
 "#;
     let result = support::typecheck(text);
 
-    let test = support::alias_variant("Test", &[], &[("Test", &[Type::unit()])]);
+    let test = support::alias_variant_implicit("Test", &[], &[("Test", &[Type::unit()])], true);
     assert_eq!(result, Ok(test));
 }
 

diff --git a/check/tests/support/mod.rs b/check/tests/support/mod.rs
@@ -295,13 +295,18 @@ where
 
 #[allow(dead_code)]
 pub fn alias(s: &str, args: &[&str], typ: ArcType) -> ArcType {
+    alias_implicit(s, args, typ, false)
+}
+
+pub fn alias_implicit(s: &str, args: &[&str], typ: ArcType, is_implicit: bool) -> ArcType {
     assert!(s.len() != 0);
-    Type::alias(
+    Type::alias_implicit(
         intern(s),
         args.iter()
             .map(|id| Generic::new(intern(id), Kind::typ()))
             .collect(),
         typ,
+        is_implicit,
     )
 }
 
@@ -311,12 +316,21 @@ pub fn variant(arg: &str, types: &[ArcType]) -> Field<Symbol, ArcType> {
 }
 
 pub fn alias_variant(s: &str, params: &[&str], args: &[(&str, &[ArcType])]) -> ArcType {
+    alias_variant_implicit(s, params, args, false)
+}
+
+pub fn alias_variant_implicit(
+    s: &str,
+    params: &[&str],
+    args: &[(&str, &[ArcType])],
+    is_implicit: bool,
+) -> ArcType {
     let variants = Type::variant(
         args.iter()
             .map(|(arg, types)| variant(arg, types))
             .collect(),
     );
-    alias(s, params, variants)
+    alias_implicit(s, params, variants, is_implicit)
 }
 
 /// Replace the variable at the `rest` part of a record for easier equality checks