• bearophile (17/17) Aug 13 2013 Are situations like this, that are potential signs of
• monarch_dodra (5/22) Aug 13 2013 Arguably, D has the "unreachable code" warning, so an
• bearophile (8/13) Aug 13 2013 The D compiler gives a warning if you add code after those return
• Timon Gehr (4/21) Aug 13 2013 Well, the following is the most generic way to get the first element of
• bearophile (7/10) Aug 13 2013 I think I have not used that idiom even with opApply, but it's
• Brian Schott (8/8) Aug 13 2013 If you get bored:
• Jonathan M Davis (4/5) Aug 13 2013 With so much stuff to do for D, how could you ever get bored. ;)

"bearophile" <bearophileHUGS lycos.com> writes:

Are situations like this, that are potential signs of 
bugs/mistakes, worth reporting with warnings?


int foo() {
     // Unconditional 'break' within a loop:
     foreach (immutable _; 0 .. 10) {
         //...
         break;
     }

     // Unconditional 'return' within a loop:
     foreach (immutable _; 0 .. 10) {
         //...
         return 0;
     }

     assert(0);
}


Bye,
bearophile

"monarch_dodra" <monarchdodra gmail.com> writes:

On Tuesday, 13 August 2013 at 14:56:32 UTC, bearophile wrote:
 Are situations like this, that are potential signs of 
 bugs/mistakes, worth reporting with warnings?


 int foo() {
     // Unconditional 'break' within a loop:
     foreach (immutable _; 0 .. 10) {
         //...
         break;
     }

     // Unconditional 'return' within a loop:
     foreach (immutable _; 0 .. 10) {
         //...
         return 0;
     }

     assert(0);
 }


 Bye,
 bearophile

Arguably, D has the "unreachable code" warning, so an 
unconditional break would short circuit the incrementation code.

So I think there is no need for a "new" warning for this, but to 
make it detect that a certain amount of code is not reachable.

"bearophile" <bearophileHUGS lycos.com> writes:

monarch_dodra:

 Arguably, D has the "unreachable code" warning, so an 
 unconditional break would short circuit the incrementation code.

 So I think there is no need for a "new" warning for this, but 
 to make it detect that a certain amount of code is not 
 reachable.

The D compiler gives a warning if you add code after those return 
and break. So the missing warning is useful when those return and 
break are at the end of the loop body.

That assert(0) is needed because D doesn't deduce that return is 
always executed.

Bye,
bearophile

Timon Gehr <timon.gehr gmx.ch> writes:

On 08/13/2013 04:56 PM, bearophile wrote:
 Are situations like this, that are potential signs of bugs/mistakes,
 worth reporting with warnings?


 int foo() {
      // Unconditional 'break' within a loop:
      foreach (immutable _; 0 .. 10) {
          //...
          break;
      }

      // Unconditional 'return' within a loop:
      foreach (immutable _; 0 .. 10) {
          //...
          return 0;
      }

      assert(0);
 }


 Bye,
 bearophile

Well, the following is the most generic way to get the first element of 
some iterable:

foreach(x;s) return x;

"bearophile" <bearophileHUGS lycos.com> writes:

Timon Gehr:

 Well, the following is the most generic way to get the first 
 element of some iterable:

 foreach(x;s) return x;

I think I have not used that idiom even with opApply, but it's 
acceptable code. And perhaps someone will find a use case even 
for the unconditional loop break.

So I think this little idea-proposal is already closed :-)

Bye,
bearophile

"Brian Schott" <briancschott gmail.com> writes:

If you get bored:
1. Run "dscanner --ast" on some source code
2. Create an XPath expression to find the code you don't like
3. Create a tool that checks the expression against the AST
4. Enjoy your low-budget static code analysis tool.

(This idea shamelessly stolen from PMD)

https://github.com/Hackerpilot/Dscanner/
http://pmd.sourceforge.net/pmd-5.0.5/xpathruletutorial.html

"Jonathan M Davis" <jmdavisProg gmx.com> writes:

On Tuesday, August 13, 2013 19:58:28 Brian Schott wrote:
 If you get bored:

With so much stuff to do for D, how could you ever get bored. ;)

- Jonathan M Davis


P.S. Keep up the good work.