Re: Another problems of newbie

Re: Another problems of newbie

[Andre]

maxsio ;D wrote:
> I need to write some program and I have problems with it. This program 
> should read text file, write words to array, sort them and than write to 
> another text file. In one book I found way how to read only singel char 
> so I thought it would be easy to link singel char and rest part of final 
> word, but I was wrong. I've written this subprogram (this program is 
> reading from keyboard, but with files is similar so...) :
> *
> procedure chars is
>   word : string(1..31);
>   char : character;
> 
> begin
>   for i in 1..30 loop
>     Get(char);
>     word:=word&(string(char));
>   end loop;
>   Put(word);
>   delay 10.0;
> end chars;
> *
> but after first letter program generate constraint error. And second 
> problem which I have is sorting array with words. To sort array I've 
> choosen QuickSort, but I don't know totally how to use it in Ada. I was 
> searching in Google, but I found only QuickSort with pointers. 
> Unfortunately I don't understand how to use them good ind this 
> algorithm. If anybody could explain usage of pointers in this algorithm 
> or write QuickSort without pointers I'd be grateful.
> Sorry for my poor English and thanks in advance. Greetings
> 
> maxsio

word:=word&(string(char)) is a concatenation of the string word and the 
char. This requiers a sting of 1 .. 32.

what you want is:
    word (i) := char;

Andr�

Another problems of newbie

[maxsio ;D]

I need to write some program and I have problems with it. This program 
should read text file, write words to array, sort them and than write to 
another text file. In one book I found way how to read only singel char so I 
thought it would be easy to link singel char and rest part of final word, 
but I was wrong. I've written this subprogram (this program is reading from 
keyboard, but with files is similar so...) :
*
procedure chars is
   word : string(1..31);
   char : character;

begin
   for i in 1..30 loop
     Get(char);
     word:=word&(string(char));
   end loop;
   Put(word);
   delay 10.0;
end chars;
*
but after first letter program generate constraint error. And second problem 
which I have is sorting array with words. To sort array I've choosen 
QuickSort, but I don't know totally how to use it in Ada. I was searching in 
Google, but I found only QuickSort with pointers. Unfortunately I don't 
understand how to use them good ind this algorithm. If anybody could explain 
usage of pointers in this algorithm or write QuickSort without pointers I'd 
be grateful.
Sorry for my poor English and thanks in advance. Greetings

maxsio
-- 
maxsio@wp.pl
GG: 1447475
IRC: irc.efnet.pl #osiolek

Re: Another problems of newbie

[Jeffrey Carter]

maxsio ;D wrote:

> procedure chars is
>   word : string(1..31);
>   char : character;
> 
> begin
>   for i in 1..30 loop
>     Get(char);
>     word:=word&(string(char));
>   end loop;
>   Put(word);
>   delay 10.0;
> end chars;

You have some basic misunderstandings. A String is just an array, so to 
assign anything to Word, it must be exactly 31 Characters long. Why 31, 
when you're only reading 30 Characters? Word (31) is undefined.

Presumably you're doing this to learn Ada. You should work through a 
text or tutorial so you understand the basics of the language before 
working on anything like this. Then when you have problems they'll be at 
a suitable level for asking here. You can find both texts and tutorials 
on line at adapower.com and adaworld.com.

When you do get to that level, you'll find that reading words is already 
done for you. See PragmARC.Word_Input and the various sorting packages 
that are part of the PragmAda Reusable Components. The PragmARCs are 
available from

http://home.earthlink.net/~jrcarter010/pragmarc.htm

-- 
Jeff Carter
"Now look, Col. Batguano, if that really is your name."
Dr. Strangelove
31

Re: Another problems of newbie

[Martin Krischik]

maxsio ;D wrote:

Just a few hints. After all, you need to learn something.

> I need to write some program and I have problems with it. This program
> should read text file, write words to array, sort them and than write to
> another text file. In one book I found way how to read only singel char so
> I thought it would be easy to link singel char and rest part of final
> word, but I was wrong. I've written this subprogram (this program is
> reading from keyboard, but with files is similar so...) :
> *
> procedure chars is
>    word : string(1..31);

I take it you are a C/C++ programmer - otherwise you would not create a
string wich is one char larger then actualy needed.

>    char : character;
> 
> begin
>    for i in 1..30 loop

for i in word'range loop

>      Get(char);
>      word:=word&(string(char));

Ada "string" is "char []" and "Ada.Strings.Unbounded" is "std::string". And
you would not use operator + () on a char [], would you? So its:

word (i) := char;

>    end loop;
>    Put(word);
>    delay 10.0;
> end chars;
> *
> but after first letter program generate constraint error. And second
> problem which I have is sorting array with words. To sort array I've
> choosen QuickSort, but I don't know totally how to use it in Ada. I was
> searching in Google, but I found only QuickSort with pointers.
> Unfortunately I don't understand how to use them good ind this algorithm.
> If anybody could explain usage of pointers in this algorithm or write
> QuickSort without pointers I'd be grateful.
> Sorry for my poor English and thanks in advance. Greetings
> 
> maxsio
> --
> maxsio@wp.pl
> GG: 1447475
> IRC: irc.efnet.pl #osiolek

Free yourself from C/C++ thinking! C/C++ are only mid-level languages and
now you work with a true high level language. Things are diffreren here.
i.E. if you need 30 characters you say 30 and 31 - no need for '\0' here.

Martin

-- 
mailto://krischik@users.sourceforge.net
http://www.ada.krischik.com

Re: Another problems of newbie

[Pascal Obry]

Martin Krischik <martin@krischik.com> writes:

> Free yourself from C/C++ thinking! C/C++ are only mid-level languages and
> now you work with a true high level language. Things are diffreren here.
> i.E. if you need 30 characters you say 30 and 31 - no need for '\0' here.
                                            ^^^
I suppose this is what you meant            not

Pascal.

-- 

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Re: Another problems of newbie

[Martin Krischik]

Pascal Obry wrote:

> 
> Martin Krischik <martin@krischik.com> writes:
> 
>> Free yourself from C/C++ thinking! C/C++ are only mid-level languages and
>> now you work with a true high level language. Things are diffreren here.
>> i.E. if you need 30 characters you say 30 and 31 - no need for '\0' here.
>                                             ^^^
> I suppose this is what you meant            not

Yes, of corse it should read: "30 and not 31".

Martin

-- 
mailto://krischik@users.sourceforge.net
http://www.ada.krischik.com