Re: GNAT Error message

["Ken Garlington" <Ken.Garlington@computer.org>]

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"Thierry&Annick" <tajz@libertysurf.fr> wrote in message
news:3A3E888E.E897AF0F@libertysurf.fr...
: Robert Dewar a �crit :
:
: > In article <3A3D01EA.37CB440B@libertysurf.fr>,
: >   Thierry&Annick <tajz@libertysurf.fr> wrote:
: >
: > > test.ada:13:38: invalid operand types for operator "-"
: > > test.ada:13:38: left operand has type "Index_Type" defined
: >                                                 at test.ada:2
: > > test.ada:13:38: right operand has type "Index_Type" defined
: > ...
:
: > Feel free to suggest how GNAT could make this clearer (and
: > submit your suggestion to report@gnat.com). I don't really
: > see any way of making this clearer.
:
: I suggest 'no binary operator "-" for enumeration type Index_Type'

Which Index_Type? Seems like the compiler should identify this more clearly
(e.g. by noting that it was the one declared at "test.ada:2").

And what if one (or more) binary operators "-" had been declared involving
Index_Type, but none had *both* a left and right operand of Index_Type
(i.e., one of the operands was a non-Index_Type in each case)? Seems like
the compiler should point out that it couldn't find a binary operator "-"
where the specific left and right operand types used didn't match any of the
"-" visible at the point of use.

And, in fact, this is exactly what the compiler did!

: >
: >
: > The compiler is telling you that there is no "-" operator
:
: So it should tell it as you do.
:
: I spent some time finding my error, I hope to remember it next time ...
:
:
: