Re: How (or Where?) to get started on Ada? (Properly)

["Peter C. Chapin" <PChapin@vtc.vsc.edu>]

On Wed, 4 Sep 2013, e.s.harney@gmail.com wrote:

> Thank you for your replies and the links! So Ada95 books/resources are 
> still a good place to get started for learning the language today then?

Yes, Ada95 materials are still relevant. They don't cover the new features 
of Ada2005 or Ada2012, of course, but with only a few little exceptions 
everything they do say is still true. Furthermore, Ada95 is still regarded 
by many as a perfectly reasonable language to use. ("I don't need no 
stink'n synchronized interfaces or executable contracts!")

One nice thing about Ada is that it has enjoyed an unusually (my opinion) 
high degree of coherence during its evolution. I send kudos to those who 
have labored to make that so. This isn't to say that it doesn't have warts 
and quirks but compared to, say, C++... well...

> Well, I'm only looking at it since Ada seems to be missing things like 
> widely-used/extensively-tested HTTP or crypto libraries. So I'll have to 
> figure out a way to using things like curl or openssl from Ada. I'm not 
> sure if something more complex than simple function is really necessary 
> for this.

Because Ada isn't as main stream as some other languages the menu of third 
party libraries available written in Ada is less than you would be used to 
coming from Java.

> Either way though, my point was that Barnes' book (judging by the table 
> of contents on Amazon) does not seem to concern itself with how to get 
> your program to do something useful.

The Barnes book is encyclopedic but it's not exactly a book about 
designing with Ada. He talks about some of the issues, but his focus is on 
presenting the raw language.

> How does Ada represent its strings internally? (Or more specifically, 
> what character set do the standard library functions for processing 
> strings assume/expect?).

There are three character types and corresponding string types.

 	Character
 	Wide_Character
 	Wide_Wide_Character

 	String
 	Wide_String
 	Wide_Wide_String

I'm sure the language lawyers here can set me straight if I get this wrong 
but my understanding is that Character is 8 bit ISO-8859-1, Wide_Character 
is 16 bit BMP part of ISO-10646, and Wide_Wide_Character is 32 bit full 
ISO-10646.

Ada source text is now assumed to be UTF-8 (or is that compilers must 
provide a mode where they accept UTF-8?).

> Is this covered by the reference manual for Ada?

There is a lot of dense language in the Ada standard regarding character 
sets.

Peter