cJass display syntax error because it process textmacros like #define instruction - you cannot use in textmacros or defines unclossed library or scope (and also closed, but unopened, in cJass you may use private define, so it must process scope and library before define and textmacro).

Try it:

Скопировать в буфер

//! textmacro itemstacking takes itemA, itemB, type
scope stack$type$ initializer I
// ...

Or it:

Скопировать в буфер

scope stacka initializer I
//! runtextmacro itemstacking("'desc'","'I007'")
endscope // remove endscope instruction in textmacro

How it look in cJass style:

Скопировать в буфер

#define itemstacking (itemA, itemB, id) = {
    scope stack##id initializer Init {
        private boolean f () {
            unit mu = GetManipulatingUnit()
            integer inve = 0 // GetInventoryHero(mu, itemB)
            item itm = null
            if inve != 6 {
                itm = null //GetItemHero(mu, itemB)
                SetItemCharges(itm, GetItemCharges(itm)+1)
            } else {
                UnitAddItemById(mu, itemB)
            }
            mu = null
            return false
        }
        
        private nothing Init () {
            // GT_AddItemAcquiredAction(function f, itemA)
        }
    }
}

itemstacking ('desc', 'I007', a)
itemstacking ('desc', 'I007', b)

It compiled as

function stacka___f takes nothing returns boolean
local unit mu=GetManipulatingUnit()
local integer inve=0
local item itm=null
if inve!=6 then
set itm=null
call SetItemCharges(itm,GetItemCharges(itm)+1)
else
call UnitAddItemById(mu,0x49303037)
endif
set mu=null
return false
endfunction
function stacka___Init takes nothing returns nothing
endfunction
function stackb___f takes nothing returns boolean
local unit mu=GetManipulatingUnit()
local integer inve=0
local item itm=null
if inve!=6 then
set itm=null
call SetItemCharges(itm,GetItemCharges(itm)+1)
else
call UnitAddItemById(mu,0x49303037)
endif
set mu=null
return false
endfunction
function stackb___Init takes nothing returns nothing
endfunction

• Fixed bugs with "flush locals" instruction.
• Fixed removing unused globals.

• Исправлены баги с инструкцией "flush locals".
• Исправлено удаление неиспользуемых переменных.