Appendix B: restructure handling of . and parens

In Table B-8, instead of treating “tuples” as the primary concern, treat
parentheses as primary and tuples as one of the contexts. Move the tuple
index access to live alongside field and method access.

Author: chriskrycho

src/appendix-02-operators.md

@@ -39,7 +39,7 @@ overload that operator is listed.
 | `->`                      | `fn(...) -> type`, <code>&vert;...&vert; -> type</code> | Function and closure return type                                      |                |
 | `.`                       | `expr.ident`                                            | Field access                                                          |                |
 | `.`                       | `expr.ident(expr, ...)`                                 | Method call                                                           |                |
-| `(`                       | `expr(expr, ...)`                                       | Function call                                                         |                |
+| `.`                       | `expr.0`, `expr.1`, etc.                                | Tuple indexing                                                        |                |
 | `..`                      | `..`, `expr..`, `..expr`, `expr..expr`                  | Right-exclusive range literal                                         | `PartialOrd`   |
 | `..=`                     | `..=expr`, `expr..=expr`                                | Right-inclusive range literal                                         | `PartialOrd`   |
 | `..`                      | `..expr`                                                | Struct literal update syntax                                          |                |
@@ -170,9 +170,9 @@ Table B-7 shows symbols that create comments.
 | `/*!...*/` | Inner block doc comment |
 | `/**...*/` | Outer block doc comment |
 
-Table B-8 shows symbols that appear in the context of using tuples.
+Table B-8 shows the contexts in which parentheses are used.
 
-<span class="caption">Table B-8: Tuples</span>
+<span class="caption">Table B-8: Parentheses</span>
 
 | Symbol                   | Explanation                                                                                 |
 | ------------------------ | ------------------------------------------------------------------------------------------- |
@@ -183,7 +183,6 @@ Table B-8 shows symbols that appear in the context of using tuples.
 | `(expr, ...)`            | Tuple expression                                                                            |
 | `(type, ...)`            | Tuple type                                                                                  |
 | `expr(expr, ...)`        | Function call expression; also used to initialize tuple `struct`s and tuple `enum` variants |
-| `expr.0`, `expr.1`, etc. | Tuple indexing                                                                              |
 
 Table B-9 shows the contexts in which curly braces are used.