How to get last unit of a group

[eskimojoe_66]

Hi, in JASS, you can use 'FirstOfGroup(<Groupname>) to get the unit that was added to a unit group most recently. I was wondering how you would be able to get the unit that added last to a unit group, i.e. 'LastOfGroup'. Now, 'LastOfGroup' doesn't exist... how could i do this?

 

[BRUTAL]

Uhm, maybe you could do something like

local unit u=null
local group unitgroup=CreateGroup()
...Do stuff with the group..
loop
    call GroupRemoveUnit(unitgroup,u)
    set u=FirstOfGroup(unitgroup)
exitwhen CountUnitsInGroup(unitgroup)==1
endloop

 

[Rushhour]

Don't believe that FirstOfGroup gives you the unit that was first added, or said in another way: You never know for sure which unit WAS added first.
I read some threads where people checked this, it depends on the position some say, some say it depends on the handle id (but there you get problems if a unit is removed and/or another one created with a "lower" number,...)

Or did anyone find the holy grail of group enumerations?

 

[Azlier]

Why do you need to get the last unit added to a group?!

 

[Komaqtion]

Ok, I did a little test on this, and here is the function:

function InitTrig_Last_in_Group takes nothing returns nothing
    local group g = CreateGroup()
    
    call GroupAddUnit( g, gg_unit_hpea_0006 )
    call BJDebugMsg( "gg_unit_hpea_0006: " + I2S( GetHandleId( gg_unit_hpea_0006 ) ) )
    call GroupAddUnit( g, gg_unit_hpea_0007 )
    call BJDebugMsg( "gg_unit_hpea_0007: " + I2S( GetHandleId( gg_unit_hpea_0007 ) ) )
    call GroupAddUnit( g, gg_unit_Hpal_0003 )
    call BJDebugMsg( "gg_unit_Hpal_0003: " + I2S( GetHandleId( gg_unit_Hpal_0003 ) ) )
    
    loop
        exitwhen FirstOfGroup( g ) == null
        call BJDebugMsg( GetUnitName( FirstOfGroup( g ) ) )
        call BJDebugMsg( I2S( GetHandleId( FirstOfGroup( g ) ) ) )
        call GroupRemoveUnit( g, FirstOfGroup( g ) )
    endloop
endfunction

As you can see I have added 2 peasants and one palading to the group in the order:
Peasant
Peasant
Paladin

And, the first section the displays this:
gg_unit_hpea_0006: 1048604
gg_unit_hpea_0007: 1048605
gg_unit_Hpal_0003: 1048603

And then the loop displayed this:
Paladin
1048603
Peasant
1048604
Peasant
1048605

And that seems very wierd to me :S

Anyways, here I have made a small snippet for LastOfGroup

library LastOfGroup
    
    globals
        public group ENUM = CreateGroup()
        
        private integer Number = 0
    endglobals
    
    private function AddGroupToGroup takes nothing returns nothing
        local unit u = GetEnumUnit()
        
        call GroupAddUnit( ENUM, u )
        
        set u = null
    endfunction
    
    private function SetNumberOfUnits takes nothing returns nothing
        set Number = Number + 1
    endfunction

    function LastOfGroup takes group g returns unit
        local integer i = 0
        local unit u
        
        call GroupClear( ENUM )
        call ForGroup( g, function AddGroupToGroup )
        
        set u = FirstOfGroup( ENUM )
        
        if u != null then
        
            loop
                set Number = 0
                
                call GroupRemoveUnit( ENUM, u )
                call ForGroup( ENUM, function SetNumberOfUnits )
                
                set u = FirstOfGroup( ENUM )
                exitwhen Number == 1
            endloop
            
        endif
        
        return u
    endfunction

endlibrary

 

[Jesus4Lyf]

You all know FirstOfGroup is deprecated.

globals
    unit EnumLast
endglobals
function LastOfGroupEnum takes nothing returns nothing
    set EnumLast=GetEnumUnit()
endfunction
function LastOfGroup takes group g returns unit
    set EnumLast=null
    call ForGroup(g,function LastOfGroupEnum)
    return EnumLast
endfunction

Try that.

But if you use this or need this at all, you're doing something poorly.

 

[Komaqtion]

Well, any1 have any comments on the results of my small "test" ? :S
I'm kinda dazzled by them XD

 

[Jesus4Lyf]

Groups are confusing, we don't know how they are implemented internally. I have a hunch that it is with a BTree - that would explain everything, I think.

 

[ZugZugZealot]

I thought he just wanted the last added to the group, not the last in the group, but the more I read the thread, the more confusing which is meant was.

If you need the last enumerated 4LyfClover's deal would work

You all know FirstOfGroup is deprecated.

globals
    unit EnumLast
endglobals
function LastOfGroupEnum takes nothing returns nothing
    set EnumLast=GetEnumUnit()
endfunction
function LastOfGroup takes group g returns unit
    set EnumLast=null
    call ForGroup(g,function LastOfGroupEnum)
    return EnumLast
endfunction

Try that.

But if you use this or need this at all, you're doing something poorly.

If you need the unit you did [ljass]call GroupAddUnit(group, unit)[/ljass] to, then just designate a global unit variable to unit where you have this...

call GroupAddUnit( bukkake, theUnit )
set lastAdded2Bukkake = theUnit

Wherever you add to group and just use "lastAdded2<group>" to get the last added to a group.

-
Anyways, the whole enumeration order is an interesting topic. I made sandbox map to try and figure out how the order works. There is a method to their madness, but I haven't figured it out.

Where you have an enum order of units such as...
0, 1, 2, 3, 4
if you remove 0: 1 becomes 0; 2 becomes 1; 3 becomes 2; 4 becomes 3
if you remove 4: the others remain the same.
However, what decides their order is beyond me.

I had it display enumeration order, group added order, unit handle id, and even in desperation coordinates.

Anyways, if anyone wants to play around with it, the map I made for it makes it fairly easy to. Also, if you wish to edit the map and add more values, change layout, go ahead.

Here's the map...