Ascii keyword??

Ascii keyword??

[Richard]

ok am new to this ada thing, so  is there a package and/or keyword i can
use to convert a decimal number to a acsii character and vice versa


thanks :)

Re: Ascii keyword??

[Pascal Obry]

Richard <richard-blunt@blueyonder.co.uk> writes:

> ok am new to this ada thing, so  is there a package and/or keyword i can
> use to convert a decimal number to a acsii character and vice versa

Nothing like that, but there is some attributes for that. Look for
'Val and 'Pos attributes in any Ada textbook.

Pascal.

-- 

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--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
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Re: Ascii keyword??

[Marin David Condic]

"Richard" <richard-blunt@blueyonder.co.uk> wrote in message
news:3A8D72D4.BBB57470@blueyonder.co.uk...
> ok am new to this ada thing, so  is there a package and/or keyword i can
> use to convert a decimal number to a acsii character and vice versa
>

It's pretty simple. There are things in Ada called "Attributes" which can be
extremely handy for a wide variety of things. In this case, there are two
attributes which are defined for all discrete types (characters being a
discrete type). They are 'Pos and 'Val and they work like function calls.
Here's basically how you would use them.

My_Int : Integer := 0 ;
My_Char : Character := ' ' ;

...

My_Char := Character'Val (33) ; -- Gives My_Char the ascii character '!'
My_Int := Character'Pos ('&') ; --  Gives My_Int the value 38.

A good example of this is in the appendix A.3.3 of the ARM. (This is where
the Latin_1 character set is defined.) If you don't have an ARM handy, look
at: http://www.adapower.org/ under "Reference" for the on-line HTML version
of the ARM. While the ARM is not the best source for teaching yourself Ada,
it is a valuable resource for looking up particulars that you may come
across in reading other texts.

Good luck with Ada!

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com
Web:      http://www.mcondic.com/

Re: Ascii keyword??

[Lao Xiao Hai]

Richard wrote:

> ok am new to this ada thing, so  is there a package and/or keyword i can
> use to convert a decimal number to a acsii character and vice versa
>
> thanks :)

The problem of converting a numeric value to a string and vice versa is
quite
nicely addressed in package Ada.Text_IO.    For example, if you have a
floating
point type, you can instantiate Ada.Text_IO.Float_IO.    There are GET and
PUT
operations available from that instantiation to convert a string to a
floating point
value or get a floating point value from a string.

This same feature is available for all the numeric types:  integers,
decimal, fixed-point,
and modular.

Richard Riehle

Re: Ascii keyword??

[David C. Hoos, Sr.]

What you need is the language-defined function
Character'Val (<integer_expression>) to convert
a number in the range 0 .. 255 to its corresponding
character, and the language-defined function
Character'Pos (<character_value>) to obtain its
position in the character set -- 0 .. 255;

E.g., Character'Val (65) returns 'A', and
Character'Pos ('A') returns 65.

"Richard" <richard-blunt@blueyonder.co.uk> wrote in message
news:3A8D72D4.BBB57470@blueyonder.co.uk...
> ok am new to this ada thing, so  is there a package and/or keyword i can
> use to convert a decimal number to a acsii character and vice versa
>
>
> thanks :)
>

Re: Ascii keyword??

[Jeffrey Carter]

"David C. Hoos, Sr." wrote:
> 
> What you need is the language-defined function ...

What he needs is to check out the Ada FAQ at www.adapower.com. If this
isn't in there, it should be.

-- 
Jeff Carter
"Hello! Smelly English K...niggets."
Monty Python & the Holy Grail

Re: Ascii keyword??

[Lao Xiao Hai]

"David C. Hoos, Sr." wrote:

> What you need is the language-defined function
> Character'Val (<integer_expression>) to convert
> a number in the range 0 .. 255 to its corresponding
> character, and the language-defined function
> Character'Pos (<character_value>) to obtain its
> position in the character set -- 0 .. 255;
>
> E.g., Character'Val (65) returns 'A', and
> Character'Pos ('A') returns 65.
>

David,

I made the assumption he needed to convert ascii strings to numbers.  That
might have been incorrect.   Often, when teaching Ada, I find that this kind
of question, when posed by someone from a C/C++ background, is not really
about the one-to-one correspondence between the character name and the
numeric ASCII value, but rather about making numbers from strings and
vice-versa.