Clean up a few uses of the word "namespace".

Since "namespace" has a specific meaning in Rust, I feel like it would
be good not to overload it too much with the sense of a scope container
like a C++ namespace.

Author: ehuss

src/attributes.md

@@ -174,7 +174,7 @@ active. All other attributes are inert.
 ## Tool attributes
 
 The compiler may allow attributes for external tools where each tool resides
-in its own namespace in the [tool prelude]. The first segment of the attribute
+in its own module in the [tool prelude]. The first segment of the attribute
 path is the name of the tool, with one or more additional segments whose
 interpretation is up to the tool.
 

src/items/generics.md

@@ -43,12 +43,8 @@ referred to with path syntax.
 
 ### Const generics
 
-*Const generic parameters* allow items to be generic over constant values. The
-const identifier introduces a name for the constant parameter, and all
-instances of the item must be instantiated with a value of the given type.
-
-<!-- TODO: update above to say "introduces a name in the [value namespace]"
-    once namespaces are added. -->
+*Const generic parameters* allow items to be generic over constant values.
+The const identifier introduces a name in the [value namespace] for the constant parameter, and all instances of the item must be instantiated with a value of the given type.
 
 The only allowed types of const parameters are `u8`, `u16`, `u32`, `u64`, `u128`, `usize`
 `i8`, `i16`, `i32`, `i64`, `i128`, `isize`, `char` and `bool`.
@@ -286,6 +282,7 @@ struct Foo<#[my_flexible_clone(unbounded)] H> {
 [arrays]: ../types/array.md
 [associated const]: associated-items.md#associated-constants
 [associated type]: associated-items.md#associated-types
+[attributes]: ../attributes.md
 [block]: ../expressions/block-expr.md
 [const contexts]: ../const_eval.md#const-context
 [const expression]: ../const_eval.md#constant-expressions
@@ -313,4 +310,4 @@ struct Foo<#[my_flexible_clone(unbounded)] H> {
 [type aliases]: type-aliases.md
 [type]: ../types.md
 [unions]: unions.md
-[attributes]: ../attributes.md
+[value namespace]: ../names/namespaces.md

src/names/namespaces.md

@@ -5,9 +5,6 @@ into separate namespaces based on the kind of entity the name refers to.
 Namespaces allow the occurrence of a name in one namespace to not conflict
 with the same name in another namespace.
 
-Within a namespace, names are organized in a hierarchy, where each level of
-the hierarchy has its own collection of named entities.
-
 There are several different namespaces that each contain different kinds of
 entities. The usage of a name will look for the declaration of that name in
 different namespaces, based on the context, as described in the [name

src/paths.md

@@ -1,10 +1,7 @@
 # Paths
 
-A *path* is a sequence of one or more path segments _logically_ separated by
-a namespace <span class="parenthetical">qualifier (`::`)</span>. If a path
-consists of only one segment, it refers to either an [item] or a [variable] in
-a local control scope. If a path has multiple segments, it always refers to an
-item.
+A *path* is a sequence of one or more path segments separated by `::` tokens.
+They are used to refer to [items], values, [types], [macros], and [attributes].
 
 Two examples of simple paths consisting of only identifier segments:
 
@@ -25,7 +22,7 @@ x::y::z;
 > _SimplePathSegment_ :\
 > &nbsp;&nbsp; [IDENTIFIER] | `super` | `self` | `crate` | `$crate`
 
-Simple paths are used in [visibility] markers, [attributes], [macros], and [`use`] items.
+Simple paths are used in [visibility] markers, [attributes], [macros][mbe], and [`use`] items.
 Examples:
 
 ```rust
@@ -384,8 +381,7 @@ mod without { // ::without
 [_SimplePathSegment_]: #simple-paths
 [_Type_]: types.md#type-expressions
 [literal]: expressions/literal-expr.md
-[item]: items.md
-[variable]: variables.md
+[items]: items.md
 [implementations]: items/implementations.md
 [use declarations]: items/use-declarations.md
 [IDENTIFIER]: identifiers.md
@@ -394,8 +390,10 @@ mod without { // ::without
 [expressions]: expressions.md
 [extern prelude]: names/preludes.md#extern-prelude
 [macro transcribers]: macros-by-example.md
-[macros]: macros-by-example.md
+[macros]: macros.md
+[mbe]: macros-by-example.md
 [patterns]: patterns.md
 [trait implementations]: items/implementations.md#trait-implementations
 [traits]: items/traits.md
+[types]: types.md
 [visibility]: visibility-and-privacy.md