[Pawn 3-pg]

I'm unable to get this code from the Pawn Tutorial to compile:

PHP Code:

//Example of an range switch statement
switch (a)
{
    case 0 .. 50:
    {
       //This code will run if 0 <= a <= 50
    }
 
    case 51 .. 100:
    {
       //This code will run if 51 <= a <= 100
    }
 
    case 101 .. 200:
    {
       //This code will run if 101 <= a <= 200
    }
 
    default:
    {
       //This code will run if all other cases fail
    }
} 


// switch_test.sp(8) : error 001: expected token: ":", but found ".."
// switch_test.sp(8) : warning 215: expression has no effect
// switch_test.sp(8) : error 001: expected token: ";", but found ":"

Is the tutorial wrong?

[The JCS]

Sourcemod uses a modified version of the Pawn language, give a look on this wiki section:
http://wiki.alliedmods.net/Category:SourceMod_Scripting

Or go to the switch explanation directly.

[rhelgeby]

Since SourcePawn is based on Pawn, I wonder why we can't use ranges in switch statements then. It would be really useful in some cases.

[BAILOPAN]

rhelgeby: We removed it because the implementation is extremely bad. It essentially expands it to a series of "if" statements, and this can mislead people into doing something like "0..100" whereas this would be much better:

if (value >= 0 && value <= 100)

Since the ".." syntax would result in:

if (value == 0 || value == 1 || value == 2 || value == 3 || value == 4 || value == 5) ...

(We could re-optimize this at run-time, but it seems like the right idea is to use if statements anyway.)

[API]

I agree about using an if statement over a range, but why not do something like this?
case 123: // Since no upper/lower bound is defined: if(a==123)
case 123 .. 456: // Lower and upper bound found: if(a<=upperbound || a>=lowerbound)

[BAILOPAN]

That's not what the compiler was generating, and we opted to remove the syntax feature rather than fix the code generation.

We could always add it back, but it's kind of a non-trivial change to fix the problem, and extremely low priority.