LCS2016_049_history < P1076

P1076 Web>VHDL2017>LCS2016_049>LCS2016_049_history (2017-07-16, JimLewis) (raw view)EditAttach
---+ Language Change Specification for Map Generics On Subprogram Call

---++ 

| <sticky><b>LCS Number:</b></sticky> | LCS-2016-049 History |
| <sticky><b>Version:</b>   </sticky> | 7 |
| <sticky><b>Date:</b>      </sticky> | 21-Mar-2017 |
| <sticky><b>Status:</b>    </sticky> | Voting |
| <sticky><b>Author:</b>    </sticky> | Jim Lewis |
| <sticky><b>Email:</b>     </sticky> | [[Main.JimLewis]] |
| <sticky><b>Source Doc:</b></sticky> | [[MapSubprogramGenericOnCall][Map Generics On Subprogram Call]] |
| <sticky><b>Summary:</b>   </sticky> | Map Generics On Subprogram Call |

---+++ Voting Results: Cast your votes here

Yes:

   1 %USERSIG{JimLewis - 21-Mar-2017}% ver 6
   1 %USERSIG{ThomasPreusser - 2017-02-07}% - ver 3
   1 %USERSIG{MartinZabel - 2017-02-26}% - ver 6
   1 %USERSIG{PatrickLehmann - 2017-03-22}% - ver 6

No:

Abstain:
   1 %USERSIG{BrentHahoe - 2017-02-16}% Version 3 - Abstain due to lack of personal time for review.
   1 %USERSIG{MartinThompson- 2017-02-17}% Version 2 - Abstain due to lack of personal time for review.

---++ Revision History
Version 7: 21-Mar-2017
   * Added edit in 3rd paragraph in 4.2.1 on page 20

 Version 6: 10-Mar-2017
   * Added edit in 5th paragraph in 6.5.7.2 on page 84

Version 5: 25-Feb-2017
   * Added text on elaboration of uninstantiated subprograms.   
      * new item c, minor edit to b, current c becomes d
   
Version 4:  24-Feb-2017
   * Deleted edit to paragraph with parentheses. Same paragraph is in 10.7.  Either edit both or neither.  Decided neither.
   * Replaced - which was displaying as ?
   
Version 3:  30-Jan-2017
   * Replaced "generic map ... actual_generic_part" with generic_map_aspect to reuse already defined terms
   * Added parameter map key words and defined parameter_map_aspect to be consistent with port_map_aspect.
      * This was an oversight as I thought 1076-2008 already added parameter map.  
   
Version 2:  21-Jan-2017
   * Added generic map before actual_generic_part
   
Version 1:  Initial 13-Jan-2017
   
---++ Reviewing Notes
At first, this does not seem likea worthy item to do,
however, it is the required step toward doing anonymous 
types on interfaces.  See LCS_2016_016

---++ Style Notes
<noautolink><sticky>
Changes are shown in %RED%red font%ENDCOLOR%.  
Deletions are %RED%<del>crossed out</del>%ENDCOLOR%. 
Editing notes in %GREEN%green font%ENDCOLOR%. 
 
---++ Relevant sections of the LRM
function calls - expressions
procedure calls - sequential statements, concurrent statements
Execution and Elaboration



---++ Comments 


In a function or procedure call, both the generic association list as well as the parameter association list are optional. How should a parser decide wether f(x =&#62; y) is a function call with parameter x set to y, or function call with generic x set to y? There might be 2 functions visible with an appropriate signature for each case.

-- %BUBBLESIG{MartinZabel - 2017-01-20}%


The parser doesn&#39;t have to decide, semantic analysis can disambiguate the expressions. Just like overloading, if the expression is ambiguous it should be rejected by the compiler.


-- %BUBBLESIG{LievenLemiengre - 2017-01-21}%


Added generic map to the call.   I think it is important that we keep consistent with other parts of the language.   If in the future we introduce some form of abbreviation, it would need to apply to all uses and in particular to both subrprogram calls and entity/component instances.

-- %BUBBLESIG{JimLewis - 2017-01-21}%


@Jim: Thanks for changing to &#34;generic map&#34;. 

I also made some fixes which I think are not worse to  bump the revision number: Within the grammar rules, I changed the font of &#34;generic&#34; in &#34;generic_association_list&#34; to italics. I also fixed two types.

-- %BUBBLESIG{MartinZabel - 2017-01-23}%


@MZ thanks for the edits.

-- %BUBBLESIG{JimLewis - 2017-01-26}%


Did you forget to change it for procedure calls?

-- %BUBBLESIG{LievenLemiengre - 2017-01-27}%


@LL  Thanks.   It was actually a test to see if you were paying attention.   Good catch.

-- %BUBBLESIG{JimLewis - 2017-01-27}%


There is some resolvable conflict between concurrent procedure calls & instantiations

lbl : foo -- is it a procedure call or an instantiation

This change makes this problem bigger 

lbl : foo generic map(...)  -- is it a procedure call or an instantiation

These things can be resolved but they&#39;re a real pain to deal with

-- %BUBBLESIG{LievenLemiengre - 2017-02-07}%


...but the pain exists since years. It just stronger :)

We can&#39;t change the fact that the final decision for procedure call vs. instantiation needs to read a lot of characters/tokens until it can decide what it is.

-- %BUBBLESIG{PatrickLehmann - 2017-02-07}%
%COMMENT%</sticky>

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Topic revision: r1 - 2017-07-16 - 16:39:47 - JimLewis
P1076