Re: ANN: Ada source code decorator

Stephen Leake <stephen_leake@xxxxxxx> writes:

Simon Wright <simon@xxxxxxxxxxxx> writes:

Stephen Leake <stephen_leake@xxxxxxx> writes:

The ASIS _standard_ is open-source; it consists of Ada specs giving
the API.

The GNAT implementation is also open-source.

So what is missing?

Something to make it clear what the actual structure is. I found it
very hard indeed to understand what the API was trying to tell me;

Perhaps there needs to be more user-friendly documentation of the ASIS
structure.

Yes. You have to understand what an API is _about_.

for example, a qualified name a.b.c is stored in something like

(a (b (c)))

which you can understand a compiler using,

Well, yes; ASIS is designed to represent the information a compiler
knows. So it helps to be able to think like a compiler :).

rather than

<name>
<component>a</component>
<component>b</component>
<component>c</component>
</name>

Well, this has nothing to do with being "open source".

You are arguing that the particular structure defined in the ASIS spec
is not one you would use for your particular application.

That is certainly your choice. Everyone else will also have a
particular choice; probably different. I suspect the choice of
structure depends heavily on the algorithm you want to implement.

It would be completely unnatural in XML to represent the concept of a
name with components as a nested structure. For a start, the XPath
expressions involved will be unmanageable.

So it will be very difficult to get agreement on a _standard_ XML
representation of Ada source code. But it's probably worth trying.

Indeed.

and asis2xml would _definitely_ produce the latter (I forget
whether it actually does at this stage).

http://www.pushface.org/asis2xml/ says the structure output by
asis2xml follows that of ASIS, so I'd be surprised if it did what you
describe above.

Well, it does what seemed like a good idea at the time :-) -- ie, what
worked.

I would argue that an XML structure that is as close as possible to
the ASIS structure would be the best one to standardize.

When you (Simon Wright), as the author of asis2xml, decided to change
the representation of a qualified name as above, what criteria were
you using to determine the "right" structure?

How would that transformation handle expressions like

Array_1 (i).Function_Pointer_2 (x, y, z).Component

It would probably be fairly close. But the argument list would be
mapped to an XML sequence, I'm sure.

When using ASIS to implement a non-trivial source processing
algorithm, the first step is to transform the ASIS-defined structure
into one that is better for your algorithm; that's what auto_text_io
does (my ASIS tool). Even if you start from an ASIS-equivalent XML
representation, that will still be true.

Yes.

For info, the output from

generic
package Basis is
type Base is abstract tagged private;
procedure Op (B : Base) is abstract;
private
type Base is abstract tagged record
V : Boolean;
end record;
end Basis;

was

<asis>
<generic_package_declaration>
<defining_identifier>Basis</defining_identifier>
<private_type_declaration kind="abstract_private_trait">
<defining_identifier>Base</defining_identifier>
<tagged_private_type_definition kind="abstract_private_trait">
</tagged_private_type_definition>
</private_type_declaration>
<procedure_declaration kind="abstract_trait">
<defining_identifier>Op</defining_identifier>
<parameter_specification kind="ordinary_trait"
mode="default_in_mode">
<defining_identifier>B</defining_identifier>
<identifier>Base</identifier>
</parameter_specification>
</procedure_declaration>
<ordinary_type_declaration>
<defining_identifier>Base</defining_identifier>
<type_definition>
<tagged_record_type_definition kind="abstract_trait">
</tagged_record_type_definition>
<record_definition>
<component_declaration>
<defining_identifier>V</defining_identifier>
<component_definition kind="ordinary_trait" size="8">
<subtype_indication>
<identifier>Boolean</identifier>
</subtype_indication>
</component_definition>
</component_declaration>
</record_definition>
</type_definition>
</ordinary_type_declaration>
</generic_package_declaration>
</asis>

which probably makes more sense to you than to me. I can get some of
it, of course, but -- for example -- what other sorts of traits are
there and what do they actually mean?
.

Relevant Pages

  • Re: ANN: Ada source code decorator
    ... Georg Bauhaus writes: ... It would be a lot easier if ASIS (the ... XML schema and not an API; the API makes using ASIS so very clumsy ... compared to the various XML processing technologies available ...
    (comp.lang.ada)
  • Re: ANN: Ada source code decorator
    ... Perhaps there needs to be more user-friendly documentation of the ASIS ... So it will be very difficult to get agreement on a _standard_ XML ... When you (Simon Wright), as the author of asis2xml, decided to change ... the representation of a qualified name as above, ...
    (comp.lang.ada)