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digitalmars.D.learn - Concat or add ~. Is this a bug?

reply jicman <jicman_member pathlink.com> writes:
Should this compile?  it should, at least, gives me warnings.

<code>
01. import std.stdio;
02. void TurnToMonDigit(char[] mon)
03. {
04.   char[] mm;
05.   mm = "I am trying to see if this also breaks" ~ mon ~ " more \n" ~
06.   "because this broke for me" ~
07.   "yep it did" ~
08.   "of course, new lines are needed\n";
09.   "new lines also\n";
10.   "this should not compile" ~
11.   " no it should not ";
12.   writefln(mm);
13. 
14. }
15. void main (char[][] args)
16. {
17.   TurnToMonDigit("JUU");
18. }
</code>

Note line 08 and 09.  They have no variable assignment.  It's just an empty

"";
"";

but what causes me more trouble is what follows,

"..." ~
"..." ~
"..." ~
"...";

a concatenation to nothing.  Well, this was a bug in my program. :-)  So, I
wasn't testing or anything. :-)

any ideas why this should compile?

thanks,

josť
Mar 21 2005
parent reply "Regan Heath" <regan netwin.co.nz> writes:
On Mon, 21 Mar 2005 22:51:29 +0000 (UTC), jicman  
<jicman_member pathlink.com> wrote:
 Should this compile?

No. IIRC a statement that is pointless or has no effect is an error. I can't, however, seem to find the part of the spec that says this, so I might be imagining it.
 <code>
 01. import std.stdio;
 02. void TurnToMonDigit(char[] mon)
 03. {
 04.   char[] mm;
 05.   mm = "I am trying to see if this also breaks" ~ mon ~ " more \n" ~
 06.   "because this broke for me" ~
 07.   "yep it did" ~
 08.   "of course, new lines are needed\n";
 09.   "new lines also\n";
 10.   "this should not compile" ~
 11.   " no it should not ";
 12.   writefln(mm);
 13.
 14. }
 15. void main (char[][] args)
 16. {
 17.   TurnToMonDigit("JUU");
 18. }
 </code>

Lines 8, 9, and 10 + 11 are pointless statements and should be errors.
 but what causes me more trouble is what follows,

 "..." ~
 "..." ~
 "..." ~
 "...";

 a concatenation to nothing.

That's another pointless statement and should be an error. Regan
Mar 21 2005
parent reply jicman <jicman_member pathlink.com> writes:
Well, it does...

Plus, I kept thinking that Windows has memory problems (which I know it does,
but this was no way to prove it. :-))  I kept looking as to why I was missing
half of my prints!  And couldn't understand why.  Then I reaaaaaaally looked at
the code and saw the bug.  So... anyway, perhaps it should be fixed.

josť

Regan Heath says...
On Mon, 21 Mar 2005 22:51:29 +0000 (UTC), jicman  
<jicman_member pathlink.com> wrote:
 Should this compile?

No. IIRC a statement that is pointless or has no effect is an error. I can't, however, seem to find the part of the spec that says this, so I might be imagining it.
 <code>
 01. import std.stdio;
 02. void TurnToMonDigit(char[] mon)
 03. {
 04.   char[] mm;
 05.   mm = "I am trying to see if this also breaks" ~ mon ~ " more \n" ~
 06.   "because this broke for me" ~
 07.   "yep it did" ~
 08.   "of course, new lines are needed\n";
 09.   "new lines also\n";
 10.   "this should not compile" ~
 11.   " no it should not ";
 12.   writefln(mm);
 13.
 14. }
 15. void main (char[][] args)
 16. {
 17.   TurnToMonDigit("JUU");
 18. }
 </code>

Lines 8, 9, and 10 + 11 are pointless statements and should be errors.
 but what causes me more trouble is what follows,

 "..." ~
 "..." ~
 "..." ~
 "...";

 a concatenation to nothing.

That's another pointless statement and should be an error. Regan

Mar 21 2005
parent reply "Regan Heath" <regan netwin.co.nz> writes:
On Mon, 21 Mar 2005 23:58:32 +0000 (UTC), jicman  
<jicman_member pathlink.com> wrote:
 Well, it does...

 Plus, I kept thinking that Windows has memory problems (which I know it  
 does,
 but this was no way to prove it. :-))  I kept looking as to why I was  
 missing
 half of my prints!  And couldn't understand why.  Then I reaaaaaaally  
 looked at
 the code and saw the bug.  So... anyway, perhaps it should be fixed.

Indeed. I'm cross-posting this to digitalmars.D.bugs so Walter will see it. Regan
 josť

 Regan Heath says...
 On Mon, 21 Mar 2005 22:51:29 +0000 (UTC), jicman
 <jicman_member pathlink.com> wrote:
 Should this compile?

No. IIRC a statement that is pointless or has no effect is an error. I can't, however, seem to find the part of the spec that says this, so I might be imagining it.
 <code>
 01. import std.stdio;
 02. void TurnToMonDigit(char[] mon)
 03. {
 04.   char[] mm;
 05.   mm = "I am trying to see if this also breaks" ~ mon ~ " more \n"  
 ~
 06.   "because this broke for me" ~
 07.   "yep it did" ~
 08.   "of course, new lines are needed\n";
 09.   "new lines also\n";
 10.   "this should not compile" ~
 11.   " no it should not ";
 12.   writefln(mm);
 13.
 14. }
 15. void main (char[][] args)
 16. {
 17.   TurnToMonDigit("JUU");
 18. }
 </code>

Lines 8, 9, and 10 + 11 are pointless statements and should be errors.
 but what causes me more trouble is what follows,

 "..." ~
 "..." ~
 "..." ~
 "...";

 a concatenation to nothing.

That's another pointless statement and should be an error. Regan


Mar 21 2005
parent Thomas Kuehne <thomas-dloop kuehne.thisisspam.cn> writes:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Regan Heath schrieb am Tue, 22 Mar 2005 12:15:25 +1200:
 On Mon, 21 Mar 2005 23:58:32 +0000 (UTC), jicman  
<jicman_member pathlink.com> wrote:
 No. IIRC a statement that is pointless or has no effect is an error. I
 can't, however, seem to find the part of the spec that says this, so I
 might be imagining it.

 <code>
 01. import std.stdio;
 02. void TurnToMonDigit(char[] mon)
 03. {
 04.   char[] mm;
 05.   mm = "I am trying to see if this also breaks" ~ mon ~ " more \n"  
 ~
 06.   "because this broke for me" ~
 07.   "yep it did" ~
 08.   "of course, new lines are needed\n";
 09.   "new lines also\n";
 10.   "this should not compile" ~
 11.   " no it should not ";
 12.   writefln(mm);
 13.
 14. }
 15. void main (char[][] args)
 16. {
 17.   TurnToMonDigit("JUU");
 18. }
 </code>




Added to DStress as http://dstress.kuehne.cn/nocompile/double_quoted_string_19.d http://dstress.kuehne.cn/nocompile/double_quoted_string_20.d Thomas -----BEGIN PGP SIGNATURE----- iD8DBQFCP7503w+/yD4P9tIRAuP7AJ9Cw8BYee44RxR3LJ9VBKfTWb6BYQCfcK2m FOIeQVHUtyCD2D2aYV2IaTs= =eCiF -----END PGP SIGNATURE-----
Mar 22 2005