Discussion 'new' return bug o.o'

[Laiev]

today, nothing to do.. So I search something to do and I found a Chinese forum.

In that forum I read (read? lol just what I can understand) some people talking about a 'new return bug'

So I just test and yes, there're other new return bug :nuts:
Don't know for what exactly it is but see the trigger:

function Int takes integer i returns integer
    return i
endfunction

function Unit takes unit u returns unit
    return u
endfunction

function I2UHelper takes integer i returns unit
    call Int(i)
    if false then
        return null
    endif
endfunction

function I2U takes integer i returns unit
    return Unit(I2UHelper(i))
endfunction

Yes, if you save the jasshelper give you a syntax error saying "Missing return" here:

function I2UHelper takes integer i returns unit
    call Int(i)
    if false then
        return null
    endif
endfunction

But you don't need other return... just Ok and press test button and...?

lol warcraft run without any problem and game start

I really don't get the reason for this return bug but here is the trigger test which come with the map:

function Trig_Init_Actions takes nothing returns nothing
    local unit u = CreateUnit(Player(0), 'hfoo', 0, 0, 0)
    local integer i = GetHandleId(u)
    local unit u2 = I2U(i)
    if u == u2 then
        call BJDebugMsg("same")
    else
        call BJDebugMsg("diff")
    endif
    call RemoveUnit(u2)
    set u = null
    set u2 = null
endfunction

//===========================================================================
function InitTrig_Init takes nothing returns nothing
    set gg_trg_Init = CreateTrigger(  )
    call TriggerAddAction( gg_trg_Init, function Trig_Init_Actions )
endfunction

opinion? thinks? ideas? anything?

 

[13lade619]

haven't tested yet.

but what happens if you put this code into a big map?
wont the JassHelper error stop it from 'compiling' your whole code properly?

 

[Weep]

Not new.

 

[Laiev]

Not new.

:banghead::banghead: I think I learn jass a bit late :thdown:

EDIT: at least someone can explain what it do? lol

 

[Darthfett]

:banghead::banghead: I think I learn jass a bit late :thdown:

EDIT: at least someone can explain what it do? lol

Is English your primary language? Just curious.

Read up on this:

http://wiki.thehelper.net/wc3/Return_Bug

 

[Executor]

The return bug is a way to typecast. You know GetHandleId(Unit)=Integer but the way back is not that easy. The return bug is a way to transform a handle back to a unit (or another handle type): I2U(Integer)=Unit.

A problem is, that I2U(Integer)=Unit is very unsafe. For example we save the ID of a unit via GetHandleId, remove the unit create a few new units and I2U(ID)= one of the new units. As the handles get recycled.

Fortunately we don't need the transformation of an integer to a handle type very often. The only situation you would need this, coming to my mind, is a struct which can save every type.

Example:

globals
   integer TYPE_INTEGER = 0
   integer TYPE_STRING  = 1
   integer TYPE_UNIT    = 2
endglobals

struct Data
   integer id
   integer type
   static method saveValue takes integer handle, integer type returns thistype
      local thistype this = thistype.allocate()
      set .id = handle
      set .type = type
   endmethod
   method getInteger takes nothing returns integer
      return .id
   endmethod
   method getUnit takes nothing returns unit
      return I2U(.id)
   endmethod
   method getString takes nothing returns string
      return I2S(.id)
   endmethod
endstruct

function someInit takes nothing returns nothing
   local Data d = Data.saveValue(someUnit,TYPE_UNIT)
   
   if d.type == TYPE_UNIT then
      set someUnit = d.getUnit()
   elseif d.type == TYPE_INTEGER then
      set someInt = d.getInteger()
   endif
endfunction

 

[Laiev]

> Is English your primary language? Just curious.

No and I know, I'm really bad with english

@Executor

thx for the explanation

 

[kingkingyyk3]

http://www.thehelper.net/forums/showthread.php?t=135583

This can replace it and it is safer. Your example is for code variable.

 

[Laiev]

http://www.thehelper.net/forums/showthread.php?t=135583

This can replace it and it is safer. Your example is for code variable.

Cool, now i can understand for what is that snipped by you

when you have posted it i just read, read and read and nothing lol lmao