Enhance and move information about macro debugging
Fixes
@@ -731,15 +731,20 @@ Rust syntax is restricted in two ways:
pairs when they occur at the beginning of, or immediately after, a `$(...)*`;
requiring a distinctive token in front can solve the problem.
-## Syntax extensions useful for the macro author
+## Syntax extensions useful in macros
-* `log_syntax!` : print out the arguments at compile time
-* `trace_macros!` : supply `true` or `false` to enable or disable macro expansion logging
* `stringify!` : turn the identifier argument into a string literal
* `concat!` : concatenates a comma-separated list of literals
-* `concat_idents!` : create a new identifier by concatenating the arguments
-The following attributes are used for quasiquoting in procedural macros:
+## Syntax extensions for macro debugging
+
+* `log_syntax!` : print out the arguments at compile time
+* `trace_macros!` : supply `true` or `false` to enable or disable macro expansion logging
+
+## Quasiquoting
+
+The following syntax extensions are used for quasiquoting Rust syntax trees,
+usually in [procedural macros](book/plugins.html#syntax-extensions):
* `quote_expr!`
* `quote_item!`
@@ -748,6 +753,8 @@ The following attributes are used for quasiquoting in procedural macros:
* `quote_tokens!`
* `quote_ty!`
+Documentation is very limited at the moment.
+
# Crates and source files
Rust is a *compiled* language. Its semantics obey a *phase distinction*
