Clarify simple function call.

[HansOlsson]

I noticed that the issue had milestone 3.7 so I thought it best to have at least a proposal for a solution; even if we decide to postpone it.

Closes #3632

Future possibilities:

• Could group reinit, assert, terminate in a sub-section of their own (and thus move them down one level), and put this explanation at that place (but still referenced from simple equation).
• Modify the grammar as it currently contains:

some-equation :
( equation-or-procedure
  | if-equation
  | for-equation
  | connect-equation
  | when-equation
)
description

equation-or-procedure :
simple-equation
| function-call

connect-equation :
connect "(" component-reference "," component-reference ")"

To me it would be logical to group function-call and connect-equation after each other inside equation-or-procedure. However, we cannot view connect-equation as a kind of function-call as connect is a keyword and break connect-equation is used for selective model extension.

[henrikt-ma]

To me it would be logical to group function-call and connect-equation after each other inside equation-or-procedure. However, we cannot view connect-equation as a kind of function-call as connect is a keyword and break connect-equation is used for selective model extension.

The only use of equation-or-procedure and statement-or-procedure that I see is that they are mentioned non-normatively when talking about how to write a recursive descent parser. If we omitted that non-normative section, we wouldn't have to draw an artificial line between what goes directly into some-equation (statement) and what goes into equation-or-procedure (statement-or-procedure).

[HansOlsson]

Delay

[henrikt-ma]

Among other remaining issues, the statement aspect of #3632 is still not addressed.

Now that 3.7 has been released and we don't have to try to rush things, I think we should also take the time to make the discussed improvements of the grammar.

[henrikt-ma]

Same remarks as on July 7:

Among other remaining issues, the statement aspect of #3632 is still not addressed.

Now that 3.7 has been released and we don't have to try to rush things, I think we >should also take the time to make the discussed improvements of the grammar.

[HansOlsson]

I have now also updated the grammar. The non-normative section was updated as well.

[HansOlsson]

The equation and statement sections have also been updated.
Having reinit under side-effect equations also implied a restructuring.

In general it would be good to have the sections somewhat match the order in the grammar I think. Now we have:

Equations:
Sections:

• Simple equations
• Side-effect equations
• For-equations
• Connect-equations
• If-equations
• When-equations

Grammar:

• simple-equation
• function-call (side-effect)
• connect-equation
• if-equation
• for-equation
• when-equation

Statements:

• Simple assignments
• Side-effect statements
• For-statements
• Break-statements
• Return-statements
• While-statements
• If-statements
• When-statements

Grammar:

• Assignment statements
• break-statement
• return-statement
• if-statement
• for-statement
• while-statement
• when-statement

However, to me reordering that should be a separate PR as it is not about simple function calls anymore; and we might consider different variants. Note that break and return currently aren't grouped with side-effect statements as they aren't function calls, but it would be possible.

I don't know the best order for if, for, while, when - but I think we should only have one.

[HansOlsson]

It should now be ready for review.
The problematic merging indicates that restructuring above should really be in a separate PR.