ColdFrame: Operation Bodies

Introduction

Operation declarations are generated in the appropriate package specification.

Normally, the body is generated as a body stub in the corresponding package body, and separate proper bodies (this is the reason why all the operations of all but protected types, and all the operations of a class bar entries, must have distinct names; see ARM 10.1.3 (14)).

The proper bodies are compilable, but raise a Not_Yet_Implemented exception if called. They are initially generated in domain.gen; move them to domain.impl, change the protection to read/write, and edit as required (remembering to remove the 'Edit this' comment at the top!)

With some limitations, it's possible instead to specify an operation's body content in the model. This has the advantage of reducing the number of implementation files to be kept under configuration management, and also makes it much simpler to change the name and profile of an operation.

"Modelling"

Given a class with an operation (Is_Set) selected,

the left of the lower panel looks like

and the right like

Click on the arrowhead by Method

and click on the text (lower) icon, which brings up a box into which you can enter the code (this is a very unreal example! more later ...)

To save, go to the left of the panel,

and click on the left arrowhead by the Specification; the right of the panel now shows one (unnamed) method, which you can revisit by double-clicking on it.

ColdFrame only allows one method. If you accidentally create another, you can delete it (it will be the bottom one, but do check!) by selecting it and clicking on the wastebin icon.

Limitations

Declarations

The given body text is inserted into the generated code as-is (properly indented). You can't add code to the subprogram's declarative region.

However, you can use a declare block: for the Is_Set function above, this could look like

declare
   Set_In_State : constant array (State_Machine_State_T) of Boolean
     := (Pushed | Held | Timed | Pushed_Again => True,
         others => False);
begin
   return Set_In_State (This.State_Machine_State);
end;

You'll have to write the code anyway, but you might consider that that is about at the limit of what's manageable.

Context

ColdFrame adds context clauses (withs) to the class package body for all classes related to this class and for associations in which this class is mentioned.

If you need more, you'll have to implement the operation in a proper body.