Syntax overview
===============

+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| expression              |    →    |      constant \| unary-message \| binary-message \| keyword-message \| ‘(’ expression ‘)’                                        |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| constant                |    →    |      self \| number \| string \| object                                                                                          |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| unary-message           |    →    |      receiver unary-send \| resend ‘.’ unary-send                                                                                |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| unary-send              |    →    |      identifier                                                                                                                  |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| binary-message          |    →    |      receiver binary-send \| resend ‘.’ binary-send                                                                              |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| binary-send             |    →    |      operator expression                                                                                                         |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| keyword-message         |    →    |      receiver keyword-send \| resend ‘.’ keyword-send                                                                            |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| keyword-send            |    →    |      small-keyword expression { cap-keyword expression }                                                                         |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| receiver                |    →    |      [ expression ]                                                                                                              |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| resend                  |    →    |      resend \| identifier                                                                                                        |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| object                  |    →    |      regular-object \| block                                                                                                     |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| regular-object          |    →    |      ‘(’ [ ‘\|’ [ ‘{’ ‘}’ ‘=’ string ] slot-list ‘\|’ ] [ code ] ‘)’                                                             |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| block                   |    →    |      ‘[’ [ ‘\|’ slot-list    ‘\|’ ] [ code ] ‘]’                                                                                 |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| slot-list               |    →    |      { unannotated-slot-list \| annotated-slot-list }                                                                            |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| annotated-slot-list     |    →    |      ‘{’ string slot-list ‘}’                                                                                                    |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| unannotated-slot-list   |    →    |      { slot ‘.’} slot [ ‘.’ ]                                                                                                    |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| code                    |    →    |      { expression ‘.’} [ ‘^’ ] expression [ ‘.’ ]                                                                                |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| slot                    |    →    |      arg-slot \| data-slot \| binary-slot \| keyword-slot                                                                        |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| arg-slot                |    →    |      argument-name                                                                                                               |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| data-slot               |    →    |      slot-name \| slot-name ‘<-’ expression \| slot-name ‘=’ expression                                                          |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| unary-slot              |    →    |      slot-name ‘=’ regular-object                                                                                                |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| binary-slot             |    →    |      operator ‘=’ regular-object \| operator [identifier] ‘=’ regular-object                                                     |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| keyword-slot            |    →    |      small-keyword {cap-keyword} ‘=’ regular-object \| small-keyword identifier {cap-keyword identifier} ‘=’ regular-object      |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| slot-name               |    →    |      identifier \| parent-name                                                                                                   |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+
| parent-name             |    →    |      identifier ‘*’                                                                                                              |
+-------------------------+---------+----------------------------------------------------------------------------------------------------------------------------------+