Different types of "for" statement

Now new betas of AdicHelper has: (scope behavior not shown)

1: for(code1;code2;code3){ /* actions */ }
-> code1; while (code2) { /* actions */; code3}

2: forp (code1;code2;code3) { /* actions */}
-> code1; do { /* actions */; code3} while (code2)

3: for (unit u; UnitsIn...(Args)) { /* actions */ }
-> globals
        group cjgrfgn_00000000=CreateGroup()
    endglobals
    call GroupEnumUnitsIn...(cjgrfgn_00000000,Args,null)
    loop
        set u=FirstOfGroup(cjgrfgn_00000000)
        exitwhen       u==null
        call GroupRemoveUnit(cjgrfgn_00000000,u)
        /* actions */
    endloop

4: for (unit u; UnitsIn...(Args) use g) { /* actions */ }
->  call GroupEnumUnitsIn...(g,Args,null)
    loop
       set u=FirstOfGroup(g)
        exitwhen       u==null
        call GroupRemoveUnit(g,u)
        /* actions */
    endloop

5: for(unit u; UnitsInGroup(g)) { /* actions */ }
-> Cycle with copying group (sorry, no code)

6: for(unit u; UnitsInGroup(g); GroupRemovePickedUnit()) { /* actions */ }
-> loop
       set u=FirstOfGroup(g)
       exitwhen u==null
       call GroupRemoveUnit(g,u)
        /* actions */
    endloop

Problems are (IMHO):

Syntax 6 use two pseudofunctions, and one of them in a special place. In this 
form group for has three pseudoarguments, and it make this form too similar 
with form 1. GroupRemovePickedUnit() is not needed if UnitsInGroup(g) would 
substituted by UnitsFromGroup(g). It will be shorter, clearer, not bug 
friendly. 
So I suggest "for(unit u; UnitsFromGroup(g)) { /* actions */ }" instead of it.

Syntax 3 use global, so vulnerable to recursive use. It may lead to subtle 
bugs, which would be hard to find. Using local group is slower, but more 
foolproof.
So I suggest to use "forg" for group for using global group, "for" - local 
group:
forg (unit u; UnitsIn...(Args)) { /* actions */ } //creates global group to 
cycle
for (unit u; UnitsIn...(Args)) { /* actions */ }  //creates local group to cycle

Syntax 4 implement new keyword "use". It is bad for so low use.
If you want a specific group, which you use already, write:
    call GroupEnumUnitsIn...(g,Args,null)
    for (unit u; UnitsFromGroup(g)) { /* actions */ } //or syntax 6 if you think "UnitsFromGroup" is bad
If you want just a use of local group, look slightly above to more clear code.

So what I really want is elimination not really needed keywords ("use" and 
"GroupRemovePickedUnit()") and second ";" in group for.

Vote, please. We need your opinions.
Original issue reported on code.google.com by sbratchi...@gmail.com on 13 Aug 2011 at 10:04
olety / cjass

Different types of "for" statement #24
