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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: gnat.string_split , howto manipulate slice numbers
Date: Tue, 29 Oct 2019 08:35:29 +0000
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Date: 2019-10-29T08:35:29+00:00
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Alain De Vos <devosalain71@gmail.com> writes:

> I have a String_Split.Slice_Number , but I need the number before.
> ...
> J := String_Split.Slice_Count (Lines);
> for I in 2 .. J loop
> ...
> This works but ,
> ...
> J := String_Split.Slice_Count (Lines) - 1 ;
> for I in 2 .. J loop
> ...
> This does not work.
> Error :
> lsblk.adb:91:44: operator for type "Slice_Number" defined at
> g-arrspl.ads:116, instance at g-strspl.ads:39 is not directly visible

The error message says that there is an operator "-" for Slice_Number,
but it needs to be made directly visible; either "use String_Split", or
"use type String_Split.Slice_Count".

However! clearly Lines is of some numeric type (Natural?) defined
earlier, for which operator "-" is visible. So use that operator
instead, by applying it before the conversion:

   J := String_Split.Slice_Count (Lines - 1);