Lua noob: What am i doing wrong ?

[Buzzer1977]

Hi,

I'm a absolute lua noob and i don't know why the table 'retval' that i'm filling with key(unit name), value (distance) pairs remains empty.
I've added a counter and some debug output, so adding the unit to the table get's called, but the table remains empty.
What am i doing wrong ? I'd guess its something trivial i just can't see because i'm new to lua.

Any help would be appreciated

Regards Buzzer
 

function units_in_range(position, range, filter, matches )     	
    retval = {}
    units = mist.getUnitsByAttribute(filter,matches,false)			
    local count = 0
    for id, unit_name in pairs(units) do	          	
        local unit = Unit.getByName(unit_name)			
        if unit ~= nil then
            local unit_position = unit:getPosition().p			
            local distance = mist.utils.get3DDist(unit_position, position )  		    
            if ( distance < range ) then                
                retval[unit_name] = distance	
                count = count + 1
                dbg("UIR: added [" .. unit_name .. "] = " .. distance .. " len: " .. #retval)		        
            end
        end
    end			
    dbg("UIR added count: " .. count .. " of units: " .. #units .. " but #retval is: " .. #retval)
    return retval
end

2022-03-20 15:06:56.176 INFO    SCRIPTING: UIR: added [BLU_GE-TBILISI-LOCHINI-GND-1-9] = 552.78357821229 len: 0
2022-03-20 15:06:56.176 INFO    SCRIPTING: UIR: added [BLU_GE-TBILISI-LOCHINI-GND-1-7] = 180.60067457258 len: 0
2022-03-20 15:06:56.177 INFO    SCRIPTING: UIR: added [BLU_GE-TBILISI-LOCHINI-GND-1-5] = 1521.1784022833 len: 0
2022-03-20 15:06:56.177 INFO    SCRIPTING: UIR: added [BLU_GE-TBILISI-LOCHINI-GND-1-10] = 618.28916828517 len: 0
2022-03-20 15:06:56.177 INFO    SCRIPTING: UIR: added [BLU_GE-TBILISI-LOCHINI-GND-1-3] = 1314.4743733626 len: 0
2022-03-20 15:06:56.177 INFO    SCRIPTING: UIR: added [BLU_GE-TBILISI-LOCHINI-GND-1-1] = 1245.1431009738 len: 0
2022-03-20 15:06:56.177 INFO    SCRIPTING: UIR: added [BLU_GE-TBILISI-LOCHINI-GND-1-4] = 1113.1370216443 len: 0
2022-03-20 15:06:56.177 INFO    SCRIPTING: UIR: added [BLU_GE-TBILISI-LOCHINI-GND-1-8] = 1874.3983142877 len: 0
2022-03-20 15:06:56.177 INFO    SCRIPTING: UIR: added [BLU_GE-TBILISI-LOCHINI-GND-1-12] = 1547.6561564401 len: 0
2022-03-20 15:06:56.177 INFO    SCRIPTING: UIR: added [BLU_GE-TBILISI-LOCHINI-GND-1-2] = 879.63989188534 len: 0
2022-03-20 15:06:56.177 INFO    SCRIPTING: UIR added count: 10 of units: 183 but #retval is: 0

[Buzzer1977]

Learned it the hard way ... LUA '#' operator won't work on key,value tables.
Is there a way to add a size() method to the table type ?
This doesn't work ...

function table.size(Table)
   local count = 0
   for k,v in pairs( Table ) do
       count = count + 1
   end 
   return count
end

[toutenglisse]

1 hour ago, Buzzer1977 said:

...Any help would be appreciated...

Hi, I don't think you can index table's entry with strings but I can be wrong. You can index it with dynamic values like unit's ID number (and have for example 2 entries : retval[1] and retval[14]). In your example I think the easiest way is (I replaced dbg by trigger.action.outText to test on screen directly) :

Spoiler

function units_in_range(position, range, filter, matches )     	
    retval = {}
    units = mist.getUnitsByAttribute(filter,matches,false)			
    local count = 0
    for id, unit_name in pairs(units) do	          	
        local unit = Unit.getByName(unit_name)			
        if unit ~= nil then
            local unit_position = unit:getPosition().p			
            local distance = mist.utils.get3DDist(unit_position, position )  		    
            if ( distance < range ) then                
                table.insert(retval, {["name"] = unit_name, ["distance"] = distance})
                count = count + 1
                trigger.action.outText("UIR: added [" .. retval[count]["name"] .. "] = " .. retval[count]["distance"] .. " len: " .. #retval, 10)		        
            end
        end
    end			
    trigger.action.outText("UIR added count: " .. count .. " of units: " .. #units .. " but #retval is: " .. #retval, 10)	
    return retval
end
units_in_range(Unit.getByName('Unité Sol-1-1'):getPoint(), 3000, {coalition = "red"}, 1)

 

[Buzzer1977]

31 minutes ago, toutenglisse said:

Hi, I don't think you can index table's entry with strings but I can be wrong. You can index it with dynamic values like unit's ID number (and have for example 2 entries : retval[1] and retval[14]). In your example I think the easiest way is (I replaced dbg by trigger.action.outText to test on screen directly) :

 

Well, indexing with all kind of values works. It just doesn't work to get the table size with '#'. A standalone function to get the size like this works:
function tsize(Table)
   local count = 0
   for k,v in pairs( Table ) do
       count = count + 1
   end 
   return count
end

n = tsize(table)

What doesn't work is to add the function to the table type.
function table.size(Table)
   local count = 0
   for k,v in pairs( Table ) do
       count = count + 1
   end 
   return count
end

n = tab.size()

The fun part is, adding functions to the string type works quite well ...

function string.starts(String,Start)
   return string.sub(String,1,string.len(Start))==Start
end
foo = 'bar'
if ( bar.starts('B')) then ....

-- to upper and replace '-' with '_'
function string.unify(String)
    return string.gsub(String:upper(), "-", "_")
end 

foo = "Red_CAP-Unit-4_3"
foo.unify() -- RED_CAP_UNIT_4_3

[ADHS]

ALA = {"A","B","C","D"}

for i = 1, #ALA do

 if ALA[i] == "B" then
    print("OK")
 else
    print("NO")
 end

end

Edited March 21, 2022 by ADHS