Inconsistencies ( return values )

[JustBreathe]

It is said that an 'if clause' should return true if the evaluation within isn't false.

PHP Code:

function onCreated()
  {
  // eval function: return ( var ? true : false );
  // evalFIX function: return ( var != false );

  eval( new TStaticVar() ); // returns false
  evalFIX( new TStaticVar() ); // returns true

  eval( false ); // returns false
  evalFIX( false ); // returns false

  eval( "" ); // returns false
  evalFIX( "" ); // returns false

  eval( null ); // returns false
  evalFIX( null ); // returns false

  eval( "false" ); // returns false
  evalFIX( "false" ); // returns false

  eval( {"stuff", "Things"} ); // returns false
  evalFIX( {"stuff", "Things"} ); // returns true

  eval( "stuff,Things" ); // returns true
  evalFIX( "stuff,Things" ); // returns true

  eval( true ); // returns true
  evalFIX( true ); // returns true

  eval( "Stuff" ); // returns true
  evalFIX( "Stuff" ); // returns true

  }

function eval( var )
  {
  return ( var ? true : false );
  }

function evalFIX( var )
  {
  return (var != false);
  } 


As shown:

Objects return false in an if clause... obj != false, returns true.

"string,var" returns true, while {"string","var"} returns false. ( string representation of array, and array )...


I believe it would be better having the evalFix, rather than the eval as return... This would allow flexability as such:

PHP Code:

  if ( pl = getPlayer("JustBreathe") )
    {
    pl.stuff;
    } else {
    return false;
    } 


[Rick]

Okay, nevermind, I jumped the gun there by misreading your post... I'll re-edit this post later.



Okay, I've looked at this problem in detail.


evalFIX() works properly, yes.
eval() - the problem may or may not be a problem.


arg ? true : false

arg before it does ?: gets cast to a float -- Objects / arrays get cast to 0.0 obviously, which is why that logic fails with them.

[JustBreathe]

Originally Posted by Rick

Okay, nevermind, I jumped the gun there by misreading your post... I'll re-edit this post later.



Okay, I've looked at this problem in detail.


evalFIX() works properly, yes.
eval() - the problem may or may not be a problem.


arg ? true : false

arg before it does ?: gets cast to a float -- Objects / arrays get cast to 0.0 obviously, which is why that logic fails with them.

Mhmm... Replace eval() by...

PHP Code:

if ( var ) return true;
else return false; 


... It does the same as arg ? true: false;

It casts the variable, yes... But that's where the problem is. It should only return false when it is false ("", null, false, "false" ), and in every other occasion, return true ( -1, "foo", {"stuff"}, new Object() ).

[Admins]

I don't know if the behaviour should be changed. The only thing that seems to be different is the check if an object is not null, and return true in that case. You can check that yourself though, with "if (obj==NULL)". For optimization it is currently doing "float(condition)!=false" instead of "condition!=false".

[JustBreathe]

Stefan: Seems like your post was deleted.

( talked about converting to float and bool )

Couldn't you work it out with type() ?

PHP Code:

function eval( var )
  {
  switch( var.type() )
    {
    case 0:
      return var != false;
    case 1:
      return var != "";
    case 2:
      return var != null;
    case 3:
      return true; // ... Just saying it has a type array means it exists!
    }
  } 


[Admins]

I have deleted and created a new post. It is doing such a check when you compare like 'condition!=false', but for optimization it is doing 'float(condition)!=0'