AllowTrailingSemisCommas < Sandbox

Sandbox Web>AllowTrailingSemisCommas (2016-04-06, RobGaddi) (raw view)EditAttach
---+ Allow Trailing Semicolons and Commas In Lists

That trailing commas and semicolons aren't allowed in lists such as port lists, port maps, and aggregates is a frequent source of irritating compile erorrs. They never take long to fix, but they're irritating and could be easily dealt with by the tools.

I propose that we allow them, i.e. that we allow the following:
<verbatim>entity dealywhopper is
  port(
    d   : in  std_logic;
    q   : out std_logic;
    clk : in  std_logic; 
    rst : in  std_logic;
  );
end entity dealywhopper;

REAL_DEAL: entity work.dealywhopper
  port map (
    d => d,
    q => q,
    clk => clk,
    rst => rst,
  );</verbatim>

The trailing semis and commas would be treated as semantically null; they're wasted characters that are simply deemed to be inoffensive by the compiler. This would apply any time a comma or semicolon delimited list appears inside of parens.
---++ Places This Structure Appears
| Syntactic Element | LRM (2008) Section | Relevant? |
| aggregate ::=<br />( element_association { , element_association } ) | [§ 9.3.3.1] | Yes, this is aggregates |
| association_list ::=<br />association_element { , association_element } | [§ 6.5.7.1] | Yes, this is port, generic, and subprogram parameter maps |
| context_reference ::=<br />context selected_name { , selected_name } ; | [§ 13.4] | No, this is for contexts and has no parens. |
| entity_class_entry_list ::=<br />entity_class_entry { , entity_class_entry } | [§ 6.9] | Sure (though who uses groups) |
| entity_name_list ::=<br />entity_designator { , entity_designator } | [§ 7.2] | No, this is the entity specifier for attributes and has no parens. |
| enumeration_type_definition ::=<br />( enumeration_literal { , enumeration_literal } ) | [§ 5.2.2.1] | Yes, this is enumerations. |
| identifier_list ::= identifier { , identifier } | [§ 5.3.3] | No, this is things like a, b : std_logic in a record. |
| index_constraint ::= ( discrete_range { , discrete_range } ) | [§ 5.3.2.1] | Yes, this is defining array ranges. |
| indexed_name ::= prefix ( expression { , expression } ) | [§ 8.4] | Yes, this is indexing an array. |
| instantiation_list ::=<br />instantiation_label { , instantiation_label } | [§ 7.3.1] | No, this is calling out instances in a configuration specification. |
| interface_list ::=<br />interface_element { ; interface_element } | [§ 6.5.6.1] | Yes, this is port/generic specifications. |
| logical_name_list ::= logical_name { , logical_name } | [§ 13.2] | No, this is listing multiple libraries on a line and has no parens. |
| record_constraint ::=<br />( record_element_constraint { , record_element_constraint } ) | [§ 5.3.3] | Yes, this is for creating constrained subtypes of records. |
| sensitivity_list ::= signal_name { , signal_name } | [§ 10.2] | Not when used in a wait statement, but explicitly allowed in §11.3 process sensitivity lists. |
| signal_list ::=<br />signal_name { , signal_name } | [§ 7.4] | No, this is a disconnect list. |
| signature ::= [ [ type_mark { , type_mark } ] [ return type_mark ] ] | [§ 4.5.3] | No, these are type marks in function signatures and have no parens. |
-- %USERSIG{RobGaddi - 2016-04-06}%

---++ Comments

<br />%COMMENT%
Topic revision: r2 - 2016-04-06 - 21:58:19 - RobGaddi
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