resolve (cleanup): Get rid of Option in PerNS

Author: petrochenkov

src/librustc_resolve/build_reduced_graph.rs

@@ -17,7 +17,7 @@ use macros::{InvocationData, LegacyScope};
 use resolve_imports::ImportDirective;
 use resolve_imports::ImportDirectiveSubclass::{self, GlobImport, SingleImport};
 use {Module, ModuleData, ModuleKind, NameBinding, NameBindingKind, ToNameBinding};
-use {Resolver, ResolverArenas};
+use {PerNS, Resolver, ResolverArenas};
 use Namespace::{self, TypeNS, ValueNS, MacroNS};
 use {resolve_error, resolve_struct_error, ResolutionError};
 
@@ -175,7 +175,11 @@ impl<'a> Resolver<'a> {
                 let subclass = SingleImport {
                     target: ident,
                     source,
-                    result: self.per_ns(|_, _| Cell::new(Err(Undetermined))),
+                    result: PerNS {
+                        type_ns: Cell::new(Err(Undetermined)),
+                        value_ns: Cell::new(Err(Undetermined)),
+                        macro_ns: Cell::new(Err(Undetermined)),
+                    },
                     type_ns_only,
                 };
                 self.add_import_directive(

src/librustc_resolve/lib.rs

@@ -700,7 +700,7 @@ pub enum Namespace {
 pub struct PerNS<T> {
     value_ns: T,
     type_ns: T,
-    macro_ns: Option<T>,
+    macro_ns: T,
 }
 
 impl<T> ::std::ops::Index<Namespace> for PerNS<T> {
@@ -709,7 +709,7 @@ impl<T> ::std::ops::Index<Namespace> for PerNS<T> {
         match ns {
             ValueNS => &self.value_ns,
             TypeNS => &self.type_ns,
-            MacroNS => self.macro_ns.as_ref().unwrap(),
+            MacroNS => &self.macro_ns,
         }
     }
 }
@@ -719,7 +719,7 @@ impl<T> ::std::ops::IndexMut<Namespace> for PerNS<T> {
         match ns {
             ValueNS => &mut self.value_ns,
             TypeNS => &mut self.type_ns,
-            MacroNS => self.macro_ns.as_mut().unwrap(),
+            MacroNS => &mut self.macro_ns,
         }
     }
 }
@@ -1726,7 +1726,7 @@ impl<'a> Resolver<'a> {
             ribs: PerNS {
                 value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
                 type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
-                macro_ns: Some(vec![Rib::new(ModuleRibKind(graph_root))]),
+                macro_ns: vec![Rib::new(ModuleRibKind(graph_root))],
             },
             label_ribs: Vec::new(),
 
@@ -1806,14 +1806,11 @@ impl<'a> Resolver<'a> {
     }
 
     /// Runs the function on each namespace.
-    fn per_ns<T, F: FnMut(&mut Self, Namespace) -> T>(&mut self, mut f: F) -> PerNS<T> {
-        PerNS {
-            type_ns: f(self, TypeNS),
-            value_ns: f(self, ValueNS),
-            macro_ns: match self.use_extern_macros {
-                true => Some(f(self, MacroNS)),
-                false => None,
-            },
+    fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
+        f(self, TypeNS);
+        f(self, ValueNS);
+        if self.use_extern_macros {
+            f(self, MacroNS);
         }
     }