Factorio Forums

bobingabout wrote:Riiiiiight.... it shouldn't, because in theory if you do it as I did in the example, you're checking to see if .gui exists, so it should just return nil.

Zanthra wrote:In Lua it is not an error to access an undefined variable. It will simply be a "nil" value. The issue is when you try to access keys in a nil value.

Zanthra wrote:I see now, interesting. How expensive is pcall as far as performance goes compared to directly calling a function? I have been warned away from using errors as control flow, but in this case it may be your best option.

I did some quick tests, and pcall with an error seems to take about 40 microseconds, and whithout an error, it has very little performance impact. So as long as you don't end up with more than 10 errors per tick, the performance impact should be fairly low.

quyxkh wrote:ugly but efficient hack: lua strings are atoms, equality testing is just pointer testing, test the help() string.

Code: Select all

    if entity.help() == stored_player_help then 

Trying that in x=1,1000 loops says it's dirt cheap.

Nexela wrote:

quyxkh wrote:ugly but efficient hack: lua strings are atoms, equality testing is just pointer testing, test the help() string.

Code: Select all

    if entity.help() == stored_player_help then 

Trying that in x=1,1000 loops says it's dirt cheap.

This hack wins the interwebs :)

eradicator wrote:Try one of the function types, e.g. get_quickbar() as those explicitily should return nil when failing.

eradicator wrote:Is that the same cost as testing for nil?

eradicator wrote:Try one of the function types, e.g. get_quickbar() as those explicitily should return nil when failing.

quyxkh wrote:

eradicator wrote:Is that the same cost as testing for nil?

eradicator wrote:Try one of the function types, e.g. get_quickbar() as those explicitily should return nil when failing.

Nope, it's not, testing says doing `do x=1,1e6 if unsub.get_quickbar()==nil then end end` is cheaper than `…unsub.help()==saved_player_help…`no matter what the unsub is, the only downside is, it won't distinguish a LuaPlayer from a player's LuaEntity.

Earendel wrote:A: Player: A LuaPlayer
B: Player Character: A LuaEntity of the "player", but is the player.character.
C: Non-player character: A LuaEntity of the type "player" but one spawned via script and has no associated player.
D: Some other LuaEntity, like a stone furnace or a piece of wall.

eradicator wrote:if .get_quickbar() returns nil on all of BCD (you just confirmed B) then wouldn't that still be the optimal solution? It makes sense btw that characters don't have quickbars, as god controllers can have a quickbar too.

/c --[[ handy table meta, htm(t) allows t:insert(1) and for k,v in t ]]
htm = setmetatable(
    {__index=table,__call=function(s,_,k) return next(s,k) end},
    {__call=function(s,t) return setmetatable(t,s) end})

psd={comment=false,nocode=true}
function psl(p,k) return print(serpent.line(p,k or psd)) end
function psb(p,k) return print(serpent.block(p,k or psd)) end
function gpsl(p,k) return game.player.print(serpent.line(p,k or psd)) end

--[[ /c locos=fef'locomotive' ]]
--[[ /c for _,l in locos do l.insert'rocket-fuel' end ]]
function fef(t,e)
    if not t then t={} end
    if type(t)=='string' then t={name=t} end
    if type(t[1])=='string' then t.name=t[1] t[1]=nil end
    if not t.name and not t.type and e then t.name=e.name end
    if not t.hop then
        return htm((e and e.surface or game.surfaces[1]) .
                                        find_entities_filtered(t))
        end
    end

quyxkh wrote:The problem is, unless my coffee has worn off it doesn't: in my tests it returns the quickbar in case B.

Here, paste this into your console:

console paste

Code: Select all

/c --[[ handy table meta, htm(t) allows t:insert(1) and for k,v in t ]]
htm = setmetatable(
    {__index=table,__call=function(s,_,k) return next(s,k) end},
    {__call=function(s,t) return setmetatable(t,s) end})

psd={comment=false,nocode=true}
function psl(p,k) return print(serpent.line(p,k or psd)) end
function psb(p,k) return print(serpent.block(p,k or psd)) end
function gpsl(p,k) return game.player.print(serpent.line(p,k or psd)) end

--[[ /c locos=fef'locomotive' ]]
--[[ /c for _,l in locos do l.insert'rocket-fuel' end ]]
function fef(t,e)
    if not t then t={} end
    if type(t)=='string' then t={name=t} end
    if type(t[1])=='string' then t.name=t[1] t[1]=nil end
    if not t.name and not t.type and e then t.name=e.name end
    if not t.hop then
        return htm((e and e.surface or game.surfaces[1]) .
                                        find_entities_filtered(t))
        end
    end

and then `/c x=fef'player'[1] gpsl{x.type,x.get_quickbar()}`.

/c

data = { [game.player.help()] = {'player'} }

for k,v in pairs(game.entity_prototypes) do
  --[[I tried spawning stuff in first, but half of it fails, and the others were all the same]]
  local hlp = v.help()
  data[hlp] = data[hlp] or {}
  table.insert(data[hlp],k)
  end
  
local i = 1
for k,v in pairs(data) do
  print('Group '..i..':\n')
  i = i+1
  print(serpent.block(v))
  end

eradicator wrote: @OP:
Btw, how do you even end up in a situation where you get arbitrary entity data ?