Re: ubyte in for loops

[DBloke]

Hi,
The new code you supplied in other post works fine, but the code in the link in
this post does not, after first try, says I have 255 tries and goes infinite on
me, this must be a bug for 64 bit windows? If I cahnge the ubyte to uint works
fine, I guess this must be a 64 bit issue

Thanks for tips :)

Re: ubyte in for loops

[bearophile]

A different version of your code with some improvements:


import std.stdio, std.cstream, std.random;

void main() {
uint chosen = uniform(1, 21);

writeln("This is a guessing game");
writeln("I have chosen a number between 1 and 20" ~
" which you must guess");

int guess = 0;

foreach_reverse (i; 1 .. 4) {
writefln("You have %s tr%s left.", i, i == 1 ? "y" : "ies");
write("enter a guess: "); // prompt for a guess
scanf("%d", &guess); // Read a guess

// check if guess correct
if (guess == chosen) {
writefln("\nYou guessed it!");
return;
}

// Check for an invalid guess
if (guess < 1 || guess > 20) // you can add brackets here if you want
writeln("I said between 1 and 20.");
else
writefln("Sorry. %s is wrong.", guess);
}

writefln("You have had three tries and failed. The number was %s", chosen);

din.getc(); // useless?
}

Bye,
bearophile

Re: ubyte in for loops

[bearophile]

Your code works, here too:
http://ideone.com/Taq71

So maybe it's the 64 bit system that gives problems. Are you able to minimize 
your code, to show just the problem? So it will become a bug report for 
bugzilla.

By the way, the D.bugs group is not for general chat, use D.learn instead.

Bye,
bearophile

Re: ubyte in for loops

[DBloke]

Hmmm most strange, using same version of compiler as yours
2.047

I have attached the file for you to try, not sure if it makes
a difference that I am running on 64 bit win7?

I am not after help, just to confirm there maybe a bug with
either ubyte or == ?

Cheers
begin 644 main.d
M:6UP;W)T('-T9"YS=&1I;RP@6]U(&UU71E(&EC;W5N="`](#,[(&EC;W5N="`^(#`[("TM:6-O
M=6YT*0T*"7L-"@D)=W)I=&5F;&XH(EEO=2!H879E("5S('1R)7,@;&5F="XB
M+"!I8V]U;G0L(&EC;W5N="`]/2`Q(#\@(GDB(#H@(FEE6]U(&AA=F4@
M:&%D('1H

Re: ubyte in for loops

[bearophile]

DBloke:

> The code was
> for(ubyte cnt = 3; cnt > 0; --cnt)
> {
> ...
> code here
> }

This program:

import std.stdio: writeln;
void main() {
for (ubyte i = 3; i > 0; --i) {
writeln(i);
}
}

Prints with dmd 2.047:
3
2
1

It's better to use the D.learn newsgroup for such questions.

Bye,
bearophile

ubyte in for loops

[DBloke]

I declared a variable cnt of ubyte first as part of the for loop
initialiser to 3, then found it odd that the loop went infinite.

I ran through the debugger and first time through it correctly
decrements value and cnt = 2, the next time round it went to -1, this
did not happen when I declared the cnt to be an uint

I then initialised cnt outside the loop and got the same behaviour

The code was
for(ubyte cnt = 3; cnt > 0; --cnt)
{
...
code here
}