efficiency help

[Spawnova]

I have an addon and one thing it does is check to see if my public note has changed and if so change it back, the only way I can think to do this is register guild roster update event and check every time it fires

I'm curious if there isn't a better way to do it that is neater here's what I have, which works fine

if event=="GUILD_ROSTER_UPDATE" then
local pt = {"Spawnova", "Shin"}
    for i=1 , GetNumGuildMembers() do --loop through all
    local name,_,_,_,_,_,Note=GetGuildRosterInfo(i)  --get name at index
        for _, value in pairs(pt) do --test name for any in list
            if name==value and Note~=SGDB[name].note then --if contains name and note is not saved note
                GuildRosterSetPublicNote(i,SGDB[name].note) --change back to old note
            end
        end
    end
end

I'm always trying to learn new/better ways to do thing if anyone sees anything that could be more effecient let me know!

[Dridzt]

API-wise nothing comes to mind but you can get rid of a for ... end loop by changing your table from array to hash.
You should also probably avoid creating a new table with your names every time the event fires.

local pt = {Spawnova=true, Shin=true}
if event=="GUILD_ROSTER_UPDATE" then
  for i=1, GetNumGuildMembers() do -- loop through all
    local name,_,_,_,_,_,Note=GetGuildRosterInfo(i)  -- get name at index
    if pt[name] and Note~=SGDB[name].note then -- if contains name and note is not saved note
       GuildRosterSetPublicNote(i,SGDB[name].note) -- change back to old note
    end
  end
end

[Spawnova]

Thanks I totally forgot about that, and setting the variable at the start of the addon rather than on the event is a good idea thank you

[Vlad]

Just some comments on the code above:

- The table can be like {["Spawnôvá"]=1,Spanky=1,["Shìn"]=1} for those special characters, otherwise you'll get an error about syntax error. [] simply lets you use anything as key.

- "Note" is should be "note" for consistency but it doesn't really matter.

- In the event that SGDB[name] is nil you will get an error for looking up "nil.note" so it would be wise to first check that SGDB[name] exists before doing the .note on it.

- In lua's boolean logic the "if ... then" the dots can be anything, true/false is the old school way, the new way is also using nil and anything else (usually 1). For example "if DB[name] then" if the DB doesn't contain the entry with the key name, it will be nil, in other words the block of code assigned after "then" will not be executed. In the case like above, if pt[name] returns nil it's basically same as the boolean "false" and if it returns anything at all then it is "true", it can be a table, a number, string, doesn't matter. As long it isn't specifically a boolean true/false, those always supersede.

That's all I had to say.

[SDPhantom]

Originally Posted by Vlad - In lua's boolean logic the "if ... then" the dots can be anything, true/false is the old school way, the new way is also using nil and anything else (usually 1). For example "if DB[name] then" if the DB doesn't contain the entry with the key name, it will be nil, in other words the block of code assigned after "then" will not be executed. In the case like above, if pt[name] returns nil it's basically same as the boolean "false" and if it returns anything at all then it is "true", it can be a table, a number, string, doesn't matter. As long it isn't specifically a boolean true/false, those always supersede.

In short, nil and boolean false are the only values that will return a false condition. All other values return a true condition. This also means unlike some other languages, Lua considers a numerical zero and empty strings/tables as true values.