Binary value

Binary value

[Bob Gratton]

Ok... now I know how to use bitwise operators... I'd like to know also how
to convert an integer value to its equivalent in binary.

e.g.: 123 => 1111011

Thanx again!

Bob

Re: Binary value

[Marin David Condic]

It could not possibly get any easier. Ada allows you to express numeric
literals in bases other than 10. The syntax is B#nnnn# where B is a base and
the nnnn is the number in appropriate base representation. (octal, hex,
binary,... base 7 or 5 if you want to be unique!) So a binary number could
be expressed as:

2#1111_1111_1111_1111#

or just for fun:

16#FFFF#
8#177777#
10#65535#

IIRC, you can only use bases between 2..16 - but that covers most of the
ground anybody would want.

Note also that burried somewhere in Text_IO are routines that will allow you
to print results using a base other than 10 - just in case you want to do a
little I/O with your bits...

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/


"Bob Gratton" <bobby@sympatico.ca> wrote in message
news:9e2x6.568987$JT5.15730002@news20.bellglobal.com...
> Ok... now I know how to use bitwise operators... I'd like to know also how
> to convert an integer value to its equivalent in binary.
>
> e.g.: 123 => 1111011
>
> Thanx again!
>
> Bob
>
>

Re: Binary value

[Bob Gratton]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 1647 bytes --]

I see... that answers half of my question. This presumes I wanna convert
from binary to Integer. But is it possible to "convert" a Integer value to
binary. For example, if one of my program's users enters a value, how can I
show him the conversion in binary?

"Marin David Condic" <marin.condic.auntie.spam@pacemicro.com> a �crit dans
le message news: 9a2dnu$sff$1@nh.pace.co.uk...
> It could not possibly get any easier. Ada allows you to express numeric
> literals in bases other than 10. The syntax is B#nnnn# where B is a base
and
> the nnnn is the number in appropriate base representation. (octal, hex,
> binary,... base 7 or 5 if you want to be unique!) So a binary number could
> be expressed as:
>
> 2#1111_1111_1111_1111#
>
> or just for fun:
>
> 16#FFFF#
> 8#177777#
> 10#65535#
>
> IIRC, you can only use bases between 2..16 - but that covers most of the
> ground anybody would want.
>
> Note also that burried somewhere in Text_IO are routines that will allow
you
> to print results using a base other than 10 - just in case you want to do
a
> little I/O with your bits...
>
> MDC
> --
> Marin David Condic
> Senior Software Engineer
> Pace Micro Technology Americas    www.pacemicro.com
> Enabling the digital revolution
> e-Mail:    marin.condic@pacemicro.com
> Web:      http://www.mcondic.com/
>
>
> "Bob Gratton" <bobby@sympatico.ca> wrote in message
> news:9e2x6.568987$JT5.15730002@news20.bellglobal.com...
> > Ok... now I know how to use bitwise operators... I'd like to know also
how
> > to convert an integer value to its equivalent in binary.
> >
> > e.g.: 123 => 1111011
> >
> > Thanx again!
> >
> > Bob
> >
> >
>
>

Re: Binary value

[Marin David Condic]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 3867 bytes --]

As I said, you have features in Text_IO to display data in forms other than
base 10.

Step 1: Bookmark this site: http://www.adapower.org/
Step 2: Click on the "Reference" button and select "On-line version of the
Ada 95 Reference Manual at AdaPower.com"
Step 3: Find: Appendix A.10.8, wherein you will find documentation on the
"Put" procedure. (Check out all the other cool stuff while you're there,
like the various Ada.Strings... packages, etc. Lots of useful tools for you
there.) A copy here for your convenience:

====================================================
procedure Put(File  : in File_Type;
              Item  : in Num;
              Width : in Field := Default_Width;
              Base  : in Number_Base := Default_Base);

procedure Put(Item  : in Num;
              Width : in Field := Default_Width;
              Base  : in Number_Base := Default_Base);

Outputs the value of the parameter Item as an integer literal, with no low
lines, no exponent, and no leading zeros (but a single zero for the value
zero), and a preceding minus sign for a negative value.
If the resulting sequence of characters to be output has fewer than Width
characters, then leading spaces are first output to make up the difference.
Uses the syntax for decimal literal if the parameter Base has the value ten
(either explicitly or through Default_Base); otherwise, uses the syntax for
based literal, with any letters in upper case.
====================================================

If you intend to do very much programming in Ada at all, you'll want to get
nice and comfortable with the ARM. Check out AdaPower as a really first rate
resource - especially the on-line version of the ARM. (BTW: Many compilers
ship with some version of the ARM available to you.)

Hope this helps.

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/


"Bob Gratton" <bobby@sympatico.ca> wrote in message
news:ub3x6.569521$JT5.15735623@news20.bellglobal.com...
> I see... that answers half of my question. This presumes I wanna convert
> from binary to Integer. But is it possible to "convert" a Integer value to
> binary. For example, if one of my program's users enters a value, how can
I
> show him the conversion in binary?
>
> "Marin David Condic" <marin.condic.auntie.spam@pacemicro.com> a �crit dans
> le message news: 9a2dnu$sff$1@nh.pace.co.uk...
> > It could not possibly get any easier. Ada allows you to express numeric
> > literals in bases other than 10. The syntax is B#nnnn# where B is a base
> and
> > the nnnn is the number in appropriate base representation. (octal, hex,
> > binary,... base 7 or 5 if you want to be unique!) So a binary number
could
> > be expressed as:
> >
> > 2#1111_1111_1111_1111#
> >
> > or just for fun:
> >
> > 16#FFFF#
> > 8#177777#
> > 10#65535#
> >
> > IIRC, you can only use bases between 2..16 - but that covers most of the
> > ground anybody would want.
> >
> > Note also that burried somewhere in Text_IO are routines that will allow
> you
> > to print results using a base other than 10 - just in case you want to
do
> a
> > little I/O with your bits...
> >
> > MDC
> > --
> > Marin David Condic
> > Senior Software Engineer
> > Pace Micro Technology Americas    www.pacemicro.com
> > Enabling the digital revolution
> > e-Mail:    marin.condic@pacemicro.com
> > Web:      http://www.mcondic.com/
> >
> >
> > "Bob Gratton" <bobby@sympatico.ca> wrote in message
> > news:9e2x6.568987$JT5.15730002@news20.bellglobal.com...
> > > Ok... now I know how to use bitwise operators... I'd like to know also
> how
> > > to convert an integer value to its equivalent in binary.
> > >
> > > e.g.: 123 => 1111011
> > >
> > > Thanx again!
> > >
> > > Bob
> > >
> > >
> >
> >
>
>

Re: Binary value

[Bob Gratton]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 4432 bytes --]

GEE!!! Thanx a lot! You cannot guess how much this will help...
I should send you a check! My VISA number! A box of chocolate chip cookies!
I'm just beginning in Ada, but you just gave me the tools I needed...

Thanx again!

"Marin David Condic" <marin.condic.auntie.spam@pacemicro.com> a �crit dans
le message news: 9a2gge$6m$1@nh.pace.co.uk...
> As I said, you have features in Text_IO to display data in forms other
than
> base 10.
>
> Step 1: Bookmark this site: http://www.adapower.org/
> Step 2: Click on the "Reference" button and select "On-line version of the
> Ada 95 Reference Manual at AdaPower.com"
> Step 3: Find: Appendix A.10.8, wherein you will find documentation on the
> "Put" procedure. (Check out all the other cool stuff while you're there,
> like the various Ada.Strings... packages, etc. Lots of useful tools for
you
> there.) A copy here for your convenience:
>
> ====================================================
> procedure Put(File  : in File_Type;
>               Item  : in Num;
>               Width : in Field := Default_Width;
>               Base  : in Number_Base := Default_Base);
>
> procedure Put(Item  : in Num;
>               Width : in Field := Default_Width;
>               Base  : in Number_Base := Default_Base);
>
> Outputs the value of the parameter Item as an integer literal, with no low
> lines, no exponent, and no leading zeros (but a single zero for the value
> zero), and a preceding minus sign for a negative value.
> If the resulting sequence of characters to be output has fewer than Width
> characters, then leading spaces are first output to make up the
difference.
> Uses the syntax for decimal literal if the parameter Base has the value
ten
> (either explicitly or through Default_Base); otherwise, uses the syntax
for
> based literal, with any letters in upper case.
> ====================================================
>
> If you intend to do very much programming in Ada at all, you'll want to
get
> nice and comfortable with the ARM. Check out AdaPower as a really first
rate
> resource - especially the on-line version of the ARM. (BTW: Many compilers
> ship with some version of the ARM available to you.)
>
> Hope this helps.
>
> 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/
>
>
> "Bob Gratton" <bobby@sympatico.ca> wrote in message
> news:ub3x6.569521$JT5.15735623@news20.bellglobal.com...
> > I see... that answers half of my question. This presumes I wanna convert
> > from binary to Integer. But is it possible to "convert" a Integer value
to
> > binary. For example, if one of my program's users enters a value, how
can
> I
> > show him the conversion in binary?
> >
> > "Marin David Condic" <marin.condic.auntie.spam@pacemicro.com> a �crit
dans
> > le message news: 9a2dnu$sff$1@nh.pace.co.uk...
> > > It could not possibly get any easier. Ada allows you to express
numeric
> > > literals in bases other than 10. The syntax is B#nnnn# where B is a
base
> > and
> > > the nnnn is the number in appropriate base representation. (octal,
hex,
> > > binary,... base 7 or 5 if you want to be unique!) So a binary number
> could
> > > be expressed as:
> > >
> > > 2#1111_1111_1111_1111#
> > >
> > > or just for fun:
> > >
> > > 16#FFFF#
> > > 8#177777#
> > > 10#65535#
> > >
> > > IIRC, you can only use bases between 2..16 - but that covers most of
the
> > > ground anybody would want.
> > >
> > > Note also that burried somewhere in Text_IO are routines that will
allow
> > you
> > > to print results using a base other than 10 - just in case you want to
> do
> > a
> > > little I/O with your bits...
> > >
> > > MDC
> > > --
> > > Marin David Condic
> > > Senior Software Engineer
> > > Pace Micro Technology Americas    www.pacemicro.com
> > > Enabling the digital revolution
> > > e-Mail:    marin.condic@pacemicro.com
> > > Web:      http://www.mcondic.com/
> > >
> > >
> > > "Bob Gratton" <bobby@sympatico.ca> wrote in message
> > > news:9e2x6.568987$JT5.15730002@news20.bellglobal.com...
> > > > Ok... now I know how to use bitwise operators... I'd like to know
also
> > how
> > > > to convert an integer value to its equivalent in binary.
> > > >
> > > > e.g.: 123 => 1111011
> > > >
> > > > Thanx again!
> > > >
> > > > Bob
> > > >
> > > >
> > >
> > >
> >
> >
>
>

Re: Binary value

[Marin David Condic]

Sucking up will get you all kinds of additional help. :-) (BTW: You forgot
to mention what an obvious Wizard I am as well as my clearly abundant
Humanitarian tendancies.)

Seriously: You will discover that Ada has just about all the clever
facilities you need to get almost any job done. You just have to be either
very familiar with the ARM and/or be good at digging around on the net a
little to find free Ada sources generously put there by her numerous
admirers and advocates.

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/


"Bob Gratton" <bobby@sympatico.ca> wrote in message
news:I74x6.569791$JT5.15739046@news20.bellglobal.com...
> GEE!!! Thanx a lot! You cannot guess how much this will help...
> I should send you a check! My VISA number! A box of chocolate chip
cookies!
> I'm just beginning in Ada, but you just gave me the tools I needed...
>
> Thanx again!
>

Re: Binary value

[chris.danx]

> I see... that answers half of my question. This presumes I wanna convert
> from binary to Integer. But is it possible to "convert" a Integer value to
> binary.

Suppose you have the value 123 in binary.  To convert to binary you need to
follow this algorithm.

while num /= 0 loop
    rem := num mod 2;    -- get remainder
    num := num - rem;
    add rem'image to front* of string;
end loop;

{I think this is the correct algorithm!}

You could do it recursively too.


Hope this helps,
Chris Campbell

*if you add rem'image onto the end you'll have to reverse the string after
you finish so it'd be better to add it to the front.  I'm assuming you'll
use an unbounded string in the loop and will convert it to a string outside
if you wish.

Re: Binary value

[Marin David Condic]

It is *MUCH* easier simply to look at what is available to you in Text_IO.
From ARM A.10.8:

=============================================
procedure Put(To   :    out String;
              Item : in     Num;
              Base : in     Number_Base := Default_Base);

Outputs the value of the parameter Item to the given string, following the
same rule as for output to a file, using the length of the given string as
the value for Width.
================================================

This will put an integer value in any base you like (almost!) into a string.
Similar stuff exists for other numeric types.

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/


"chris.danx" <chris.danx@ntlworld.com> wrote in message
news:K84x6.4066$MZ2.743519@news2-win.server.ntlworld.com...
> > I see... that answers half of my question. This presumes I wanna convert
> > from binary to Integer. But is it possible to "convert" a Integer value
to
> > binary.
>
> Suppose you have the value 123 in binary.  To convert to binary you need
to
> follow this algorithm.
>
> while num /= 0 loop
>     rem := num mod 2;    -- get remainder
>     num := num - rem;
>     add rem'image to front* of string;
> end loop;
>
> {I think this is the correct algorithm!}
>
> You could do it recursively too.
>
>
> Hope this helps,
> Chris Campbell
>
> *if you add rem'image onto the end you'll have to reverse the string after
> you finish so it'd be better to add it to the front.  I'm assuming you'll
> use an unbounded string in the loop and will convert it to a string
outside
> if you wish.
>
>

Re: Binary value

[Smark]

"chris.danx" <chris.danx@ntlworld.com> wrote in message
news:K84x6.4066$MZ2.743519@news2-win.server.ntlworld.com...
> > I see... that answers half of my question. This presumes I wanna convert
> > from binary to Integer. But is it possible to "convert" a Integer value to
> > binary.
>
> Suppose you have the value 123 in binary.  To convert to binary you need to
> follow this algorithm.
>
> while num /= 0 loop
>     rem := num mod 2;    -- get remainder
>     num := num - rem;
>     add rem'image to front* of string;
> end loop;
>
> {I think this is the correct algorithm!}

Well, Chris, you would probably change your mind if you tried it!
As in your example, say you start with 123.

First pass through loop:
rem := 123 mod 2 ( = 1)
num := 123 - 1 ( = 122)
add "1" to front of string   -- so the string now looks like "1"

Second pass:
rem := 122 mod 2 ( = 0)
num := 122 - 0 ( = 122)
add "0" to front of string   -- so the string now looks like "01"

Third pass:
rem := 122 mod 2 ( = 0)
num := 122 - 0 ( = 122)
add "0" to front of string   -- so the string now looks like "001"

Beginning to see a problem here?

I think the algorithm you were trying to think of goes something like:

Rem := Num;
Exp := 31;
Index := 1;
while Exp >= 0 loop
    Check := 2 ** Exp;
    if Rem >= Check then
        Bit_String(Index) := '1';
    else
        Bit_String(Index) := '0';
    end if;
    Rem := Rem - Check;
    Exp := Exp - 1;
    Index := Index + 1;
end loop;

However, there are much easier ways.  You should take a look at the
facilities provided in Text_Io, as Marin mentioned.  Also, if you
want to do something with the bits other than display them, you could
do an unchecked_conversion to a packed bit array of the same size as
the number.

Regards,
Mark
Arlington, Texas

Re: Binary value

[Smark]

"Smark" <nobody@home.com> wrote in message
news:9a2qhh$jee4@cui1.lmms.lmco.com...
>
> "chris.danx" <chris.danx@ntlworld.com> wrote in message
> news:K84x6.4066$MZ2.743519@news2-win.server.ntlworld.com...
> > > I see... that answers half of my question. This presumes I wanna convert
> > > from binary to Integer. But is it possible to "convert" a Integer value to
> > > binary.
> >
> > Suppose you have the value 123 in binary.  To convert to binary you need to
> > follow this algorithm.
> >
> > while num /= 0 loop
> >     rem := num mod 2;    -- get remainder
> >     num := num - rem;
> >     add rem'image to front* of string;
> > end loop;
> >
> > {I think this is the correct algorithm!}
>
> Well, Chris, you would probably change your mind if you tried it!
> As in your example, say you start with 123.
>
> First pass through loop:
> rem := 123 mod 2 ( = 1)
> num := 123 - 1 ( = 122)
> add "1" to front of string   -- so the string now looks like "1"
>
> Second pass:
> rem := 122 mod 2 ( = 0)
> num := 122 - 0 ( = 122)
> add "0" to front of string   -- so the string now looks like "01"
>
> Third pass:
> rem := 122 mod 2 ( = 0)
> num := 122 - 0 ( = 122)
> add "0" to front of string   -- so the string now looks like "001"
>
> Beginning to see a problem here?
>
> I think the algorithm you were trying to think of goes something like:
>
Okay, I take it back.  The algorithm I provided does work, but it is
not the one you were thinking of.  That would be more like:

while num /= 0 loop
    rem := num mod 2;    -- get remainder
    num := Floor(num/2);
    add rem'image to front* of string;
end loop;

Mark
Arlington, Texas

Re: Binary value

[chris.danx]

I forgot to divide by 2, that's silly.

so it should have been num := (num - rem)/2;

I'll remember that next time,

Thanks
Chris Campbell

Re: Binary value

[Phaedrus]

Yeah, I suppose you could do it with an algorithm.  But why bother?
The machine stores the values in binary, so just take advantage of the
fact.  Create a packed array of bits at the same location as the integer
to be converted.  Then just write the array out with a "for" loop.

It's not as easy as using the Put routine, but I like the elegance.  No muss,
no fuss, no bother.  By the way, this will also help you in doing the reverse,
where Text_io will leave you high and dry.   If you want to convert an inputted
binary number to base ten, once you've read it in it's no bother at all.  And
no work, too!

Phaedrus
"chris.danx" <chris.danx@ntlworld.com> wrote in message
news:K84x6.4066$MZ2.743519@news2-win.server.ntlworld.com...
> > I see... that answers half of my question. This presumes I wanna convert
> > from binary to Integer. But is it possible to "convert" a Integer value to
> > binary.
>
> Suppose you have the value 123 in binary.  To convert to binary you need to
> follow this algorithm.
>
> while num /= 0 loop
>     rem := num mod 2;    -- get remainder
>     num := num - rem;
>     add rem'image to front* of string;
> end loop;
>
> {I think this is the correct algorithm!}
>
> You could do it recursively too.
>
>
> Hope this helps,
> Chris Campbell
>
> *if you add rem'image onto the end you'll have to reverse the string after
> you finish so it'd be better to add it to the front.  I'm assuming you'll
> use an unbounded string in the loop and will convert it to a string outside
> if you wish.
>
>
>

Re: Binary value

[Phaedrus]

> > It's not as easy as using the Put routine, but I like the elegance.  No
muss,
> > no fuss, no bother.  By the way, this will also help you in doing the
reverse,
> > where Text_io will leave you high and dry.   If you want to convert an
inputted
> > binary number to base ten, once you've read it in it's no bother at all.
And
> > no work, too!
>
> Hunh??
I've often thought that the "default base" in text_io should allow you to set
the default INPUT base, too, so that users of it could just specify that they
wanted the user to be able to plug in a number in a certain base without
using the base and pound signs.  Unfortunately, it doesn't work that way.

> To convert an inputted binary number to base ten, simply enter it as a
> binary number.  If the program says "Get(N)", you can legally provide
> 38, 2#1001#, 16#DEADBEEF#, etc.

True, and it works great, except that the base and pound signs are
sort of a pain.  If you were going to enter, say, 30 or 40 binary numbers,
each consisting of 8 or more digits, orif you're writing a utility
to be used by less-than-advanced users, who might balk at writing the
base and the pound signs, or to convert binary data that is input as an
ASCII stream by an external device.... I can think of many situations where the
user might object to typing in the base and pound signs.  (For instance,
what if the calculator in windows required you to put the base and pounds
around a number?  Who'd use it?)
In that case, you're pretty much left with using a loop to get the number.  And
once you've got it, it's kind of cool to be able to convert it without any
calculation.
I really love the look on people's faces when they ask to see the algorithm
for verification!  "There isn't one" isn't an answer they're used to hearing.

Phaedrus

"Marc A. Criley" <mcqada@earthlink.net> wrote in message
news:3AC5C72F.8108A613@earthlink.net...
> Phaedrus wrote:
> >
> > Yeah, I suppose you could do it with an algorithm.  But why bother?
> > The machine stores the values in binary, so just take advantage of the
> > fact.  Create a packed array of bits at the same location as the integer
> > to be converted.  Then just write the array out with a "for" loop.
>
> When you've got Put, why bother with packed arrays and so on?
>
>   Put(N, Base => 2);  -- Done!
>
> >
> > It's not as easy as using the Put routine, but I like the elegance.  No
muss,
> > no fuss, no bother.  By the way, this will also help you in doing the
reverse,
> > where Text_io will leave you high and dry.   If you want to convert an
inputted
> > binary number to base ten, once you've read it in it's no bother at all.
And
> > no work, too!
>
> Hunh??
>
> To convert an inputted binary number to base ten, simply enter it as a
> binary number.  If the program says "Get(N)", you can legally provide
> 38, 2#1001#, 16#DEADBEEF#, etc.
>
> -------------------------------------------------------------
>
> with Ada.Integer_Text_Io;
> use  Ada.Integer_Text_Io;
> with Text_IO;
> use  Text_IO;
>
> procedure Binary_IO is
>
>    N : Integer;
>
> begin
>    loop
>       Put("Enter # (0 to exit): ");
>       Get(N);
>       exit when N = 0;
>       Put("As base 2: ");
>       Put(N, Base => 2);
>       New_Line;
>       Put("As base 8: ");
>       Put(N, Base => 8);
>       New_Line;
>       Put("As base 13: ");
>       Put(N, Base => 13);
>       New_Line;
>       Put("As base 16: ");
>       Put(N, Base => 16);
>       New_Line(2);
>    end loop;
> end Binary_IO;
>
> Here's a sample run:
>
> $ binary_io
> Enter # (0 to exit): 20
> As base 2:    2#10100#
> As base 8:       8#24#
> As base 13:      13#17#
> As base 16:      16#14#
>
> Enter # (0 to exit): 2#1101#
> As base 2:     2#1101#
> As base 8:       8#15#
> As base 13:      13#10#
> As base 16:       16#D#
>
> Enter # (0 to exit): 16#ABCD#
> As base 2: 2#1010101111001101#
> As base 8:   8#125715#
> As base 13:   13#17032#
> As base 16:    16#ABCD#
>
> Enter # (0 to exit): 0
> $
>

Re: Binary value

[Robert A Duff]

"Phaedrus" <phaedrusalt@hotmail.com> writes:

> I've often thought that the "default base" in text_io should allow you to set
> the default INPUT base, too, so that users of it could just specify that they
> wanted the user to be able to plug in a number in a certain base without
> using the base and pound signs.  Unfortunately, it doesn't work that way.

You can read the thing as a string, and then say something like
T'Image("2#" & The_Input_String & "#").

- Bob

Re: Binary value

[David C. Hoos, Sr.]

Don't you mean
T'Value ("2#" & The_Input_String & "#") instead of
T'Image ?
.

"Robert A Duff" <bobduff@world.std.com> wrote in message
news:wccr8zc2s5v.fsf@world.std.com...
> "Phaedrus" <phaedrusalt@hotmail.com> writes:
>
> > I've often thought that the "default base" in text_io should allow you
to set
> > the default INPUT base, too, so that users of it could just specify that
they
> > wanted the user to be able to plug in a number in a certain base without
> > using the base and pound signs.  Unfortunately, it doesn't work that
way.
>
> You can read the thing as a string, and then say something like
> T'Image("2#" & The_Input_String & "#").
>
> - Bob

Re: Binary value

[Marc A. Criley]

Robert A Duff wrote:
> 
> "Phaedrus" <phaedrusalt@hotmail.com> writes:
> 
> > I've often thought that the "default base" in text_io should allow you to set
> > the default INPUT base, too, so that users of it could just specify that they
> > wanted the user to be able to plug in a number in a certain base without
> > using the base and pound signs.  Unfortunately, it doesn't work that way.
> 
> You can read the thing as a string, and then say something like
> T'Image("2#" & The_Input_String & "#").

Yeah, I would either do this (except use 'Value instead of 'Image, like
David mentioned :-), or Get from a string.

I rarely do direct numeric input, especially if it's interactive.  I use
Get_Line, which gives me a chance to more simply handle things like C/Rs
or do some kind of input validation, and then extract the value from
that string.

Marc

Re: Binary value

[chris.danx]

What about a routine that takes a string with a O,B,D,H at the end to
identify the base.

e.g.     101B
          101D
          101H
          101O

maybe this'd be difficult to do but you could put a separator between number
and Base.

    101:B for example

Just a thought,
Chris Campbell

Re: Binary value

[Marin David Condic]

Here's a trick that might not have occurred to you: You want to set a
"default base" and let the user type in a number like that without having to
put in all the dingleberries around the digits. (Digits in this case is a
misnomer. What is the word I want?)

Prefix    : constant String := "16#" ;
Suffix    : constant String := "#" ;
....
Text_IO.Get_Line (Some_String, Last) ;
....
Integer_Text_IO.Get (
    From => Prefix & Some_String (1..Last) & Suffix,
    Item => Some_Integer,
    Last => Last) ;
....

Naturally, you can do some setup with the prefix & suffix strings to make
them selectable by the user at runtime. In the end, you probably want to
read numbers in as strings anyway because you will want to create more
forgiving editing than you customarily get immediately from Ada. (Quite
often a response can be a number of things besides a number. Picture in your
mind: "Enter the number or type 'Exit' to go back or 'Quit' to
terminate...")

Just another way of removing the epidermis from the household feline.

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/


"Phaedrus" <phaedrusalt@hotmail.com> wrote in message
news:2GLx6.16115$aP5.1507862@newsread2.prod.itd.earthlink.net...
> I've often thought that the "default base" in text_io should allow you to
set
> the default INPUT base, too, so that users of it could just specify that
they
> wanted the user to be able to plug in a number in a certain base without
> using the base and pound signs.  Unfortunately, it doesn't work that way.
>
> > To convert an inputted binary number to base ten, simply enter it as a
> > binary number.  If the program says "Get(N)", you can legally provide
> > 38, 2#1001#, 16#DEADBEEF#, etc.
>
> True, and it works great, except that the base and pound signs are
> sort of a pain.  If you were going to enter, say, 30 or 40 binary numbers,
> each consisting of 8 or more digits, orif you're writing a utility
> to be used by less-than-advanced users, who might balk at writing the
> base and the pound signs, or to convert binary data that is input as an
> ASCII stream by an external device.... I can think of many situations
where the
> user might object to typing in the base and pound signs.  (For instance,
> what if the calculator in windows required you to put the base and pounds
> around a number?  Who'd use it?)
> In that case, you're pretty much left with using a loop to get the number.
And
> once you've got it, it's kind of cool to be able to convert it without any
> calculation.
> I really love the look on people's faces when they ask to see the
algorithm
> for verification!  "There isn't one" isn't an answer they're used to
hearing.
>

Re: Binary value

[Jeffrey Carter]

"chris.danx" wrote:
> 
> > I see... that answers half of my question. This presumes I wanna convert
> > from binary to Integer. But is it possible to "convert" a Integer value to
> > binary.
> 
> Suppose you have the value 123 in binary.  To convert to binary you need to
> follow this algorithm.
> 

[incorrect algorithm deleted]

Ignoring the question of what the correct algorithm is, why would you
want to implement this (specific to binary) algorithm, when Text_IO
already provides this capability for any base from 2 to 16? It's much
easier and more flexible to use Text_IO.Integer_IO.Put and extract the
part of the result between the '#'s.

Jeffrey Carter

Re: Binary value

[chris.danx]

> [incorrect algorithm deleted]

one mistake made in haste!  I appologise!

> Ignoring the question of what the correct algorithm is, why would you
> want to implement this (specific to binary) algorithm, when Text_IO
> already provides this capability for any base from 2 to 16? It's much
> easier and more flexible to use Text_IO.Integer_IO.Put and extract the
> part of the result between the '#'s.

Guess it's just me.  This is how we done conversions in school and it was
the first thing that popped into my head.  You're right i should provide a 2
to 16 base feature which would just be slight modification (with added
complications for base > 10).

Chris

Re: Binary value

[Robert A Duff]

"chris.danx" <chris.danx@ntlworld.com> writes:

> one mistake made in haste!  I appologise!

Don't apologize -- it was very instructive.  You made Jeffrey Carter's
point quite nicely, which was that you should use existing code that
works, if you can.  ;-) ;-)

- Bob

Re: Binary value

[Robert A Duff]

Jeffrey Carter <jeffrey.carter@boeing.com> writes:

> Ignoring the question of what the correct algorithm is, why would you
> want to implement this (specific to binary) algorithm, when Text_IO
> already provides this capability for any base from 2 to 16? It's much
> easier and more flexible to use Text_IO.Integer_IO.Put and extract the
> part of the result between the '#'s.

Good point, but I can think of a couple of reasons why someone might
want to avoid using Text_IO at all: it's big (which matters if you care
about space, and don't have a clever linker), and it's not pragma-Pure.

I'd recommend 'Image and 'Value rather than Text_IO, even though they
have their faults, too.

- Bob

Re: Binary value

[Larry Hazel]

Bob Gratton wrote:
> 
> Ok... now I know how to use bitwise operators... I'd like to know also how
> to convert an integer value to its equivalent in binary.
> 
> e.g.: 123 => 1111011
> 
> Thanx again!
> 
> Bob

To write a binary constant use 2#1111011#, if I remember correctly.

Larry