Steve Teale <steve.teale britseyeview.com> writes:

for (; a<b; a++);

is illegal in D.

Doesn't this break a lot of C and C++ code?

Sergey Gromov <snake.scaly gmail.com> writes:

Thu, 19 Mar 2009 06:35:37 -0400, Steve Teale wrote:

 for (; a<b; a++);
 
 is illegal in D.
 
 Doesn't this break a lot of C and C++ code?

for (; a<b; a++) {}

is legal.  I don't think that an empty statement after for is used in "a
lot of code."

=?UTF-8?B?QWxleGFuZGVyIFDDoW5law==?= writes:

Sergey Gromov wrote:
 for (; a<b; a++) {}
 
 is legal.  I don't think that an empty statement after for is used in "a
 lot of code."

Only in Enterprise Software!

BCS <none anon.com> writes:

Hello Sergey,

 Thu, 19 Mar 2009 06:35:37 -0400, Steve Teale wrote:
 
 for (; a<b; a++);
 
 is illegal in D.
 
 Doesn't this break a lot of C and C++ code?
 

 for (; a<b; a++) {}
 
 is legal.  I don't think that an empty statement after for is used in
 "a lot of code."
 

it's a trivial fix and easy to find. Heck, you hardly need to think!

bearophile <bearophileHUGS lycos.com> writes:

BCS:
 it's a trivial fix and easy to find. Heck, you hardly need to think!

And it helps to avoid other kinds of bugs quite less easy to find. I have found
one of such bugs porting C code to D, the line after the for(); was meant to be
looped on :-)

Bye,
bearophile

Walter Bright <newshound1 digitalmars.com> writes:

BCS wrote:
 Thu, 19 Mar 2009 06:35:37 -0400, Steve Teale wrote:

 for (; a<b; a++);

 is illegal in D.

 Doesn't this break a lot of C and C++ code?

 for (; a<b; a++) {}

 is legal.  I don't think that an empty statement after for is used in
 "a lot of code."

 
 it's a trivial fix and easy to find. Heck, you hardly need to think!

No, it isn't easy to find. This is in D because a colleague of mine, who 
was an expert C programmer (the best in the company I was working for), 
came to me with:

for (xxx; i < 10; i++);
{
      ... code ...
}

and said he could not figure out why his loop executed only and exactly 
once. He'd fiddled with it for a whole afternoon. He said he must be 
missing something obvious. I said you've got an extra ; after the ). He 
smacked his head and about fell over backwards.

So it's illegal in D, along with:

    if (condition);

and similar constructs. Have to use a { } to indicate a blank statement.

"Denis Koroskin" <2korden gmail.com> writes:

On Thu, 19 Mar 2009 20:32:54 +0300, Walter Bright <newshound1 digitalmars.com>
wrote:

 BCS wrote:
 Thu, 19 Mar 2009 06:35:37 -0400, Steve Teale wrote:

 for (; a<b; a++);

 is illegal in D.

 Doesn't this break a lot of C and C++ code?

 for (; a<b; a++) {}

 is legal.  I don't think that an empty statement after for is used in
 "a lot of code."

  it's a trivial fix and easy to find. Heck, you hardly need to think!

 No, it isn't easy to find. This is in D because a colleague of mine, who  
 was an expert C programmer (the best in the company I was working for),  
 came to me with:

 for (xxx; i < 10; i++);
 {
       ... code ...
 }

 and said he could not figure out why his loop executed only and exactly  
 once. He'd fiddled with it for a whole afternoon. He said he must be  
 missing something obvious. I said you've got an extra ; after the ). He  
 smacked his head and about fell over backwards.

 So it's illegal in D, along with:

     if (condition);

 and similar constructs. Have to use a { } to indicate a blank statement.

Funny enough, or programming department chief posted the following question in
our corporate newsgroup:

Why the hell this function enters infinite loop?

void treeWalkWithoutRecursion( Node* head )
{
    Stack   s;
    s.push( head );
    while ( !s.empty() );
    {
        Node* tmp = s.pop();
        if ( !tmp->marked )
        {
            if ( tmp->right  )
                s.push( tmp->right );
            s.push( tmp );
            if ( tmp->left )
                s.push( tmp->left );
            tmp->marked = true;
        }
        else
            doSomeThing( tmp );
    }
}

"Denis Koroskin" <2korden gmail.com> writes:

On Thu, 19 Mar 2009 20:43:18 +0300, Denis Koroskin <2korden gmail.com> wrote:

 On Thu, 19 Mar 2009 20:32:54 +0300, Walter Bright  
 <newshound1 digitalmars.com> wrote:

 BCS wrote:
 Thu, 19 Mar 2009 06:35:37 -0400, Steve Teale wrote:

 for (; a<b; a++);

 is illegal in D.

 Doesn't this break a lot of C and C++ code?

 for (; a<b; a++) {}

 is legal.  I don't think that an empty statement after for is used in
 "a lot of code."

  it's a trivial fix and easy to find. Heck, you hardly need to think!

 No, it isn't easy to find. This is in D because a colleague of mine,  
 who was an expert C programmer (the best in the company I was working  
 for), came to me with:

 for (xxx; i < 10; i++);
 {
       ... code ...
 }

 and said he could not figure out why his loop executed only and exactly  
 once. He'd fiddled with it for a whole afternoon. He said he must be  
 missing something obvious. I said you've got an extra ; after the ). He  
 smacked his head and about fell over backwards.

 So it's illegal in D, along with:

     if (condition);

 and similar constructs. Have to use a { } to indicate a blank statement.

 Funny enough, or programming department chief posted the following  
 question in our corporate newsgroup:

 Why the hell this function enters infinite loop?

 void treeWalkWithoutRecursion( Node* head )
 {
     Stack   s;
     s.push( head );
     while ( !s.empty() );
     {
         Node* tmp = s.pop();
         if ( !tmp->marked )
         {
             if ( tmp->right  )
                 s.push( tmp->right );
             s.push( tmp );
             if ( tmp->left )
                 s.push( tmp->left );
             tmp->marked = true;
         }
         else
             doSomeThing( tmp );
     }
 }

That was less than a week ago. I'd say that this type of bugs will live as long
as C++ lives.

Walter Bright <newshound1 digitalmars.com> writes:

Denis Koroskin wrote:
 That was less than a week ago. I'd say that this type of bugs will live 
 as long as C++ lives.

The thing is, even if the programmer *intended* to put the ; there, it 
looks like a bug to the maintenance programmer, and he has to spend 
extra effort determining if it was intended or not.

I doubt anyone types { } by accident.

"Rioshin an'Harthen" <rharth75 hotmail.com> writes:

"Walter Bright" <newshound1 digitalmars.com> kirjoitti viestissä 
news:gpu1sn$sn2$1 digitalmars.com...
 Denis Koroskin wrote:
 That was less than a week ago. I'd say that this type of bugs will live 
 as long as C++ lives.

 The thing is, even if the programmer *intended* to put the ; there, it 
 looks like a bug to the maintenance programmer, and he has to spend extra 
 effort determining if it was intended or not.

 I doubt anyone types { } by accident.

I have a habit of indenting the semicolon on the following line, if I wanted 
a blank statement, like

for (...; ...; ...)
    ;

Much clearer in my opinion than having it on the same line as the for 
construct. 

Walter Bright <newshound1 digitalmars.com> writes:

Rioshin an'Harthen wrote:
 "Walter Bright" <newshound1 digitalmars.com> kirjoitti viestissä 
 I doubt anyone types { } by accident.

 
 I have a habit of indenting the semicolon on the following line, if I 
 wanted a blank statement, like
 
 for (...; ...; ...)
    ;
 
 Much clearer in my opinion than having it on the same line as the for 
 construct.

Yes, that's ok, too. The only issue with it as far as working it into 
the language goes is then the parser and lexer do not have a clean 
separation - whitespace has meaning in one case.

Sean Kelly <sean invisibleduck.org> writes:

== Quote from Walter Bright (newshound1 digitalmars.com)'s article
 Rioshin an'Harthen wrote:
 "Walter Bright" <newshound1 digitalmars.com> kirjoitti viestissä
 I doubt anyone types { } by accident.

 I have a habit of indenting the semicolon on the following line, if I
 wanted a blank statement, like

 for (...; ...; ...)
    ;

 Much clearer in my opinion than having it on the same line as the for
 construct.

 Yes, that's ok, too. The only issue with it as far as working it into
 the language goes is then the parser and lexer do not have a clean
 separation - whitespace has meaning in one case.

Sounds like HTTP/HTML.  The best I've come up with so far for parsing
that stuff is to have the lexer actually return tokens representing whitespace
in some instances.  It's totally ridiculous.

Walter Bright <newshound1 digitalmars.com> writes:

Sean Kelly wrote:
 Sounds like HTTP/HTML.  The best I've come up with so far for parsing
 that stuff is to have the lexer actually return tokens representing whitespace
 in some instances.  It's totally ridiculous.

When you see ad-hoc designs like that, it's obvious the designer has no 
experience with compilers. It's why every programmer should take a basic 
course in compiler design <g>.

Sean Kelly <sean invisibleduck.org> writes:

== Quote from Walter Bright (newshound1 digitalmars.com)'s article
 Sean Kelly wrote:
 Sounds like HTTP/HTML.  The best I've come up with so far for parsing
 that stuff is to have the lexer actually return tokens representing whitespace
 in some instances.  It's totally ridiculous.

 When you see ad-hoc designs like that, it's obvious the designer has no
 experience with compilers. It's why every programmer should take a basic
 course in compiler design <g>.

I very much agree.  In fact, I'd go so far as to say that my compiler design
course was the single most valuable CS course I took while in college.  It's
amazing how many problems I encounter have something to do with parsing
or language translation.  It's also amazing how many crappy parsers there
are out there for these same tasks.  Clearly, compiler design doesn't get
as much attention as it should in undergrad CS.

Walter Bright <newshound1 digitalmars.com> writes:

Sean Kelly wrote:
 I very much agree.  In fact, I'd go so far as to say that my compiler design
 course was the single most valuable CS course I took while in college.  It's
 amazing how many problems I encounter have something to do with parsing
 or language translation.  It's also amazing how many crappy parsers there
 are out there for these same tasks.  Clearly, compiler design doesn't get
 as much attention as it should in undergrad CS.

Reminds me of a metal shop class I heard about where for the first 
assignment each student was handed a chunk of metal and a file. His job 
was to file out an end wrench. The idea was to get a feel for working 
metal, besides developing an appreciation for what power tools do!

It also filtered out the impatient, slap-dash and careless people who 
should never be around metal milling machines.

In my high school wood shop, we were each handed a chunk of wood, a 
try-square, and a plane. Our job was to use the plane to create a 
perfectly square block. We weren't allowed to use any power tools until 
we passed that. I still remember the shrieks of agony from some of the 
students as the teacher would lay the square on it, point to a crack of 
light seeping under it, and pronounce "not square yet!"

Good times.

Georg Wrede <georg.wrede iki.fi> writes:

Sean Kelly wrote:
 == Quote from Walter Bright (newshound1 digitalmars.com)'s article
 Sean Kelly wrote:
 Sounds like HTTP/HTML.  The best I've come up with so far for parsing
 that stuff is to have the lexer actually return tokens representing whitespace
 in some instances.  It's totally ridiculous.

 When you see ad-hoc designs like that, it's obvious the designer has no
 experience with compilers. It's why every programmer should take a basic
 course in compiler design <g>.

 
 I very much agree.  In fact, I'd go so far as to say that my compiler design
 course was the single most valuable CS course I took while in college.  It's
 amazing how many problems I encounter have something to do with parsing
 or language translation.  It's also amazing how many crappy parsers there
 are out there for these same tasks.  Clearly, compiler design doesn't get
 as much attention as it should in undergrad CS.

Sometimes I need to have a command line UI in a program. Such programs 
usually have 5 to 10 commands, with their parameters. One command per line.

So far I have tested and split the command line with regular 
expressions, because using a parser generator has felt like shooting 
mosquitos with a shotgun.

What would your strategy be?

Walter Bright <newshound1 digitalmars.com> writes:

Georg Wrede wrote:
 Sometimes I need to have a command line UI in a program. Such programs 
 usually have 5 to 10 commands, with their parameters. One command per line.
 
 So far I have tested and split the command line with regular 
 expressions, because using a parser generator has felt like shooting 
 mosquitos with a shotgun.
 
 What would your strategy be?

If it's 5 or 10, you can get by with ad-hoc. But if you find yourself 
repeatedly fixing bugs in the parsing, it's time to consider a more 
principled approach.

Sean Kelly <sean invisibleduck.org> writes:

Walter Bright wrote:
 Georg Wrede wrote:
 Sometimes I need to have a command line UI in a program. Such programs 
 usually have 5 to 10 commands, with their parameters. One command per 
 line.

 So far I have tested and split the command line with regular 
 expressions, because using a parser generator has felt like shooting 
 mosquitos with a shotgun.

 What would your strategy be?

 
 If it's 5 or 10, you can get by with ad-hoc. But if you find yourself 
 repeatedly fixing bugs in the parsing, it's time to consider a more 
 principled approach.

I've found that once I created one lexer it could be re-used pretty 
easily for other languages too.  And recursive descent parsers are 
trivial to write.  It may be overkill for command-line parameters, but 
for anything remotely structured it's generally worth using.

Walter Bright <newshound1 digitalmars.com> writes:

Sean Kelly wrote:
 I've found that once I created one lexer it could be re-used pretty 
 easily for other languages too.  And recursive descent parsers are 
 trivial to write.  It may be overkill for command-line parameters, but 
 for anything remotely structured it's generally worth using.

When I was looking into parsing date strings, I thought it would be much 
easier if I adopted a lex/parse style approach. The result is in 
std.dateparse. The payoff is I've had very little trouble with it.

Georg Wrede <georg.wrede iki.fi> writes:

Walter Bright wrote:
 Sean Kelly wrote:
 I've found that once I created one lexer it could be re-used pretty 
 easily for other languages too.  And recursive descent parsers are 
 trivial to write.  It may be overkill for command-line parameters, but 
 for anything remotely structured it's generally worth using.

 
 When I was looking into parsing date strings, I thought it would be much 
 easier if I adopted a lex/parse style approach. The result is in 
 std.dateparse. The payoff is I've had very little trouble with it.

Ah, seems you can't parse dates in Nepal.

Read dateparse.d, and found this in line 81:

         if (
             year == year.init ||
             (month < 1 || month > 12) ||
             (day < 1 || day > 31) ||
             (hours < 0 || hours > 23) ||
             (minutes < 0 || minutes > 59) ||
             (seconds < 0 || seconds > 59) ||
             (tzcorrection != int.min &&
              ((tzcorrection < -2300 || tzcorrection > 2300) ||
               (tzcorrection % 10)))
             )

The last line here causes timezones that are not at full 10 minutes, to 
fail.

Kathmandu, Nepal is UTC+5:45, according to Wikipedia TimeZone.

Georg Wrede <georg.wrede iki.fi> writes:

Walter Bright wrote:
 Sean Kelly wrote:
 I've found that once I created one lexer it could be re-used pretty 
 easily for other languages too.  And recursive descent parsers are 
 trivial to write.  It may be overkill for command-line parameters, but 
 for anything remotely structured it's generally worth using.

 
 When I was looking into parsing date strings, I thought it would be much 
 easier if I adopted a lex/parse style approach. The result is in 
 std.dateparse. The payoff is I've had very little trouble with it.

It's a shame that this kind of lexing/parsing seems to need gotos. I 
always feel guilty if I put a goto in my code. (Guess I've had too stern 
teachers, or something...)

Georg Wrede <georg.wrede iki.fi> writes:

Georg Wrede wrote:
 Walter Bright wrote:
 (Guess I've had too stern teachers, or something...)

But then in those times, when somebody said "Michael Jackson", everybody 
thought of structured programming, not pop-icon tragedies.

Robert Fraser <fraserofthenight gmail.com> writes:

Sean Kelly wrote:
 The best I've come up with so far for parsing
 that stuff is to have the lexer actually return tokens representing whitespace
 in some instances.  It's totally ridiculous.

The Descent port of the DMDFE lexer does this for formatting source 
code. It's a neat trick for formatting, but shouldn't be necessary for 
compilation.

Also, was there ever a consensus on whether whitespace has meaning in XML?

BCS <ao pathlink.com> writes:

Reply to Walter,

 BCS wrote:
 
 Thu, 19 Mar 2009 06:35:37 -0400, Steve Teale wrote:
 
 for (; a<b; a++);
 
 is illegal in D.
 
 Doesn't this break a lot of C and C++ code?
 

 for (; a<b; a++) {}
 
 is legal.  I don't think that an empty statement after for is used
 in "a lot of code."
 

 it's a trivial fix and easy to find. Heck, you hardly need to think!
 

 No, it isn't easy to find. This is in D because a colleague of mine,
 who was an expert C programmer (the best in the company I was working
 for), came to me with:
 

Um, that's not what I was referring to. The problem the OP referenced seems 
trivial enough to me: I try to compile my translated code and get a nice 
error

Line 3: use '{ }' for an empty statement, not a ';'

I jump to that line, figure out if it was a bug in the original C code or 
if it is supposed to be that way and and fix it

Steve Teale <steve.teale britseyeview.com> writes:

Walter Bright Wrote:

 BCS wrote:
 Thu, 19 Mar 2009 06:35:37 -0400, Steve Teale wrote:

 for (; a<b; a++);

 is illegal in D.

 Doesn't this break a lot of C and C++ code?

 for (; a<b; a++) {}

 is legal.  I don't think that an empty statement after for is used in
 "a lot of code."

 
 it's a trivial fix and easy to find. Heck, you hardly need to think!

 
 No, it isn't easy to find. This is in D because a colleague of mine, who 
 was an expert C programmer (the best in the company I was working for), 
 came to me with:
 
 for (xxx; i < 10; i++);
 {
       ... code ...
 }
 
 and said he could not figure out why his loop executed only and exactly 
 once. He'd fiddled with it for a whole afternoon. He said he must be 
 missing something obvious. I said you've got an extra ; after the ). He 
 smacked his head and about fell over backwards.
 
 So it's illegal in D, along with:
 
     if (condition);
 
 and similar constructs. Have to use a { } to indicate a blank statement.

I just find this scary, because although it says at the top of the page "most
of this will be familiar to C/C++ programmers" this little fact means I have to
go through all of the familiar constructs with a fine tooth comb.

Also, nobody is answering the question. I can work out the alternatives, but
I'd just prefer it if existing code worked. I used to use the idiom I quote all
the time.

Walter Bright <newshound1 digitalmars.com> writes:

Steve Teale wrote:
 I just find this scary, because although it says at the top of the
 page "most of this will be familiar to C/C++ programmers" this little
 fact means I have to go through all of the familiar constructs with a
 fine tooth comb.

It shouldn't be scary, because the idea is if some common C struct is 
not acceptable in D, one gets a decent compiler error message. A scary 
thing would be if the code was silently accepted but did something 
different.

 Also, nobody is answering the question. I can work out the
 alternatives, but I'd just prefer it if existing code worked. I used
 to use the idiom I quote all the time.

I'm not understanding your question, then.

"Denis Koroskin" <2korden gmail.com> writes:

On Thu, 19 Mar 2009 22:05:21 +0300, Walter Bright <newshound1 digitalmars.com>
wrote:

 Steve Teale wrote:
 I just find this scary, because although it says at the top of the
 page "most of this will be familiar to C/C++ programmers" this little
 fact means I have to go through all of the familiar constructs with a
 fine tooth comb.

 It shouldn't be scary, because the idea is if some common C struct is  
 not acceptable in D, one gets a decent compiler error message. A scary  
 thing would be if the code was silently accepted but did something  
 different.

 Also, nobody is answering the question. I can work out the
 alternatives, but I'd just prefer it if existing code worked. I used
 to use the idiom I quote all the time.

 I'm not understanding your question, then.

I believe he is asking for a way to force that code to compile (a compiler
switch or have it enabled by default).

Gide Nwawudu <gide btinternet.com> writes:

On Thu, 19 Mar 2009 14:16:25 -0400, Steve Teale
<steve.teale britseyeview.com> wrote:

Walter Bright Wrote:

 BCS wrote:
 Thu, 19 Mar 2009 06:35:37 -0400, Steve Teale wrote:

 for (; a<b; a++);

 is illegal in D.

 Doesn't this break a lot of C and C++ code?

 for (; a<b; a++) {}

 is legal.  I don't think that an empty statement after for is used in
 "a lot of code."

 
 it's a trivial fix and easy to find. Heck, you hardly need to think!

 
 No, it isn't easy to find. This is in D because a colleague of mine, who 
 was an expert C programmer (the best in the company I was working for), 
 came to me with:
 
 for (xxx; i < 10; i++);
 {
       ... code ...
 }
 
 and said he could not figure out why his loop executed only and exactly 
 once. He'd fiddled with it for a whole afternoon. He said he must be 
 missing something obvious. I said you've got an extra ; after the ). He 
 smacked his head and about fell over backwards.
 
 So it's illegal in D, along with:
 
     if (condition);
 
 and similar constructs. Have to use a { } to indicate a blank statement.

I just find this scary, because although it says at the top of the page "most
of this will be familiar to C/C++ programmers" this little fact means I have to
go through all of the familiar constructs with a fine tooth comb.

Also, nobody is answering the question. I can work out the alternatives, but
I'd just prefer it if existing code worked. I used to use the idiom I quote all
the time.


 ... but I'd just prefer it if existing code worked ...

What D is saying, is that the existing code is likely to be wrong, and
should be altered before it compiles. Besides C!=D so I don't see the
problem.

Gide

Ary Borenszweig <ary esperanto.org.ar> writes:

BCS wrote:
 Hello Sergey,
 
 Thu, 19 Mar 2009 06:35:37 -0400, Steve Teale wrote:

 for (; a<b; a++);

 is illegal in D.

 Doesn't this break a lot of C and C++ code?

 for (; a<b; a++) {}

 is legal.  I don't think that an empty statement after for is used in
 "a lot of code."

 
 it's a trivial fix and easy to find. Heck, you hardly need to think!

It's not easy to find. I didn't understand why that "for" was illegal 
until I saw Alexander Pánek's second answer and noticed there was a 
semicolon. I didn't understand why "for (; a<b; a++)" was wrong. :-P

BCS <ao pathlink.com> writes:

Reply to Ary,

 It's not easy to find.
 

See my reply to walter

Don <nospam nospam.com> writes:

Steve Teale wrote:
 for (; a<b; a++);
 
 is illegal in D.
 
 Doesn't this break a lot of C and C++ code?

It breaks a lot of broken C and C++ code.

Steve Teale <steve.teale britseyeview.com> writes:

Don Wrote:

 Steve Teale wrote:
 for (; a<b; a++);
 
 is illegal in D.
 
 Doesn't this break a lot of C and C++ code?

 
 It breaks a lot of broken C and C++ code.

OK, that's possibly the case, but you know that among C programmers in
particular there was an absolute prohibition on typing more characters than
necessary.

=?UTF-8?B?QWxleGFuZGVyIFDDoW5law==?= writes:

Steve Teale wrote:
 Don Wrote:
 
 Steve Teale wrote:
 for (; a<b; a++);

 is illegal in D.

 Doesn't this break a lot of C and C++ code?

 It breaks a lot of broken C and C++ code.

 
 OK, that's possibly the case, but you know that among C programmers in
particular there was an absolute prohibition on typing more characters than
necessary.

It’s just one character more in D. Really just the closing curly bracket 
that adds up.

for(;;); vs. for(;;){}

"Denis Koroskin" <2korden gmail.com> writes:

On Thu, 19 Mar 2009 19:58:48 +0300, Alexander Pánek
<alexander.panek brainsware.org> wrote:

 Steve Teale wrote:
 Don Wrote:

 Steve Teale wrote:
 for (; a<b; a++);

 is illegal in D.

 Doesn't this break a lot of C and C++ code?

 It breaks a lot of broken C and C++ code.

  OK, that's possibly the case, but you know that among C programmers in  
 particular there was an absolute prohibition on typing more characters  
 than necessary.

 It’s just one character more in D. Really just the closing curly bracket  
 that adds up.

 for(;;); vs. for(;;){}

In D, you can for(;){} :p

BCS <ao pathlink.com> writes:

Reply to Denis,

 On Thu, 19 Mar 2009 19:58:48 +0300, Alexander Pánek
 <alexander.panek brainsware.org> wrote:
 
 Steve Teale wrote:
 
 Don Wrote:
 
 Steve Teale wrote:
 
 for (; a<b; a++);
 
 is illegal in D.
 
 Doesn't this break a lot of C and C++ code?
 

 It breaks a lot of broken C and C++ code.
 

 OK, that's possibly the case, but you know that among C programmers
 in  particular there was an absolute prohibition on typing more
 characters  than necessary.
 

 It's just one character more in D. Really just the closing curly
 bracket  that adds up.
 
 for(;;); vs. for(;;){}
 

 In D, you can for(;){} :p
 

or

int i;
for(if(i%2) i++; i< 10; i++) {}

Robert Fraser <fraserofthenight gmail.com> writes:

Steve Teale wrote:
 for (; a<b; a++);
 
 is illegal in D.
 
 Doesn't this break a lot of C and C++ code?

Among my top 10 D features! This has caught more bugs in my code than 
any "warning"s have in any other language (I do that a lot...).

bearophile <bearophileHUGS lycos.com> writes:

Denis Koroskin:
I'd say that this type of bugs will live as long as C++ lives.<

Such people may even start using warnings and some lint tool. And if no lint
tool that currently exists is able to warn about those bugs (and I seriously
doubt this) then it's time to fix/create a C++ lint able to do this too.

On the other hand what you say suggests me that the usage of lint tools isn't
so widespread, so it may be good to add the D compiler/language some of the
basic lint-like functionality I was talking for. I'll keep asking for some of
such features.

Bye,
bearophile