Gearswap Help Thread!

[dlsmd]

I've run into several differences just today, particularly load() accepting only functions and not strings. You're an open-source guy, right?

load (chunk [, chunkname [, mode [, env]]])

Loads a chunk.
If chunk is a string, the chunk is this string. If chunk is a function, load calls it repeatedly to get the chunk pieces. Each call to chunk must return a string that concatenates with previous results. A return of an empty string, nil, or no value signals the end of the chunk.

there is also
loadstring()
loadfile()

[Jeanne Renault]

load (chunk [, chunkname [, mode [, env]]])

Loads a chunk.
If chunk is a string, the chunk is this string. If chunk is a function, load calls it repeatedly to get the chunk pieces. Each call to chunk must return a string that concatenates with previous results. A return of an empty string, nil, or no value signals the end of the chunk.

there is also
loadstring()
loadfile()

Except loadstring()--which is the one I need--no longer exists as of 5.2, nor does it exist in Luacore. I've tried calling it and it always fails, with the error message suggesting Luacore thinks it's a variable. Then again it probably wouldn't work right even if it did exist.

I figured out the problem with the sets, though. Instead of trying to assign oldSet or newSet to sets.engaged.Subtle or sets.engaged.Accurate (the possible values of oldValue/newValue) it's treating oldValue and newValue as part of the name. Unfortunately, without some way to convert strings to names, I can't fix it.

[dlsmd]

Except loadstring()--which is the one I need--no longer exists as of 5.2, nor does it exist in Luacore. I've tried calling it and it always fails, with the error message suggesting Luacore thinks it's a variable. Then again it probably wouldn't work right even if it did exist.

I figured out the problem with the sets, though. Instead of trying to assign oldSet or newSet to sets.engaged.Subtle or sets.engaged.Accurate (the possible values of oldValue/newValue) it's treating oldValue and newValue as part of the name. Unfortunately, without some way to convert strings to names, I can't fix it.

all loadstring() does is takes a string and decodes it to code
i.e.
loadstring("68656c6c6f") == "hello"

[Jeanne Renault]

all loadstring() does is takes a string and decodes it to code
i.e.
loadstring("68656c6c6f") == "hello"

That's the most useless thing I've ever heard of. Please tell me you're joking.

[dlsmd]

That's the most useless thing I've ever heard of. Please tell me you're joking.

you can do this
f = assert (loadstring ("print 'hello, world'"))
f () --> hello, world
but its slower then
function f() print('hello, world') end
f() --> hello, world

its the only way to encrypt your lua code in any way but yes thats all you can do with it

[Jeanne Renault]

its the only way to encrypt your lua code in any way but yes thats all you can do with it

The command reference for 5.1 said loadstring() would evaluate a string as code and even provided examples of using it for that. I figured it would do the same thing in 5.2 if it still existed.

This is the worst language since Ada.

[Byrthnoth]

It's possible that loadstring isn't exposed to the user environment in gearswap (because I missed it initially and no one requested it).

Lua is yet another high level scripting language. I don't find it that much more offensive than anything else I've tried. 5.1 has its issues, but 5.2 had some problems deeper in the code than we cared to dive.

[dlsmd]

It's possible that loadstring isn't exposed to the user environment in gearswap (because I missed it initially and no one requested it).

Lua is yet another high level scripting language. I don't find it that much more offensive than anything else I've tried. 5.1 has its issues, but 5.2 had some problems deeper in the code than we cared to dive.

and its way faster/eaiser the xml lol

[Jeanne Renault]

It's possible that loadstring isn't exposed to the user environment in gearswap (because I missed it initially and no one requested it).

Really? I'm the first person who asked about it? o.o

Lua is yet another high level scripting language. I don't find it that much more offensive than anything else I've tried. 5.1 has its issues, but 5.2 had some problems deeper in the code than we cared to dive.

Lua is the only "high level scripting language" without switch-case or eval functions that I've ever heard of. At what point do the Powers That Be finally have enough and say "Lua, you're full of crap, we're demoting you to mid-level"?

[dlsmd]

Lua is the only "high level scripting language" without switch-case or eval functions that I've ever heard of. At what point do the Powers That Be finally have enough and say "Lua, you're full of crap, we're demoting you to mid-level"?

but it does tho some things have to be built manualy

[Jeanne Renault]

but it does

You've just been trolling me this entire time, haven't you.

[dlsmd]

You've just been trolling me this entire time, haven't you.

no byrth would have called me out in a heart beat

[Jeanne Renault]

By the looks of things, I'm not gonna get anywhere on this problem unless Byrth adds eval or switch-case functions to Luacore. Or the god of technology replaces all instances of Luacore with a Python interpreter. Wish in one hand and crap in the other though.

But if you do add those, Byrth, I'll sing your praises from the gates of Castle Adoulin.

EDIT: Well crap, turns out the solution was to use "oldSet = sets.engaged[oldValue]" and "newSet = sets.engaged[newValue]" instead. Let's see if it does what I want it to now.

no byrth would have called me out in a heart beat

You said Lua is easier than XML. That's definitely trolling.

[dlsmd]

By the looks of things, I'm not gonna get anywhere on this problem unless Byrth adds eval or switch-case functions to Luacore. Or the god of technology replaces all instances of Luacore with a Python interpreter. Wish in one hand and crap in the other though.

if your talking eval as checking to see if code works just do this
for
a=2
if a==1 then
just
print(a==1) -- will show false
and there are already way to switch the case of strings its in the strings lib
and as far as things like this
this is java
public class SwitchDemo {
public static void main(String[] args) {

int month = 8;
String monthString;
switch (month) {
case 1: monthString = "January";
break;
case 2: monthString = "February";
break;
--etc.
}
System.out.println(monthString);
}
}
this is lua
local month = 8
local monthString
if month = 1 then
monthString = "January"
elseif month == 2 then
monthString = "February"
--etc.
print(monthString)

and if you talking about converting from number to string
tostring()
or string to number
tonumber()

lua 5.2 also has goto

and there is a addon called eval to test code as well

[Jeanne Renault]

if your talking eval as checking to see if code works

I'm not. In most scripting languages nowadays there's an eval() function that takes a string and parses it as code. In Ruby, for example,

instructions = "5.times print 'odelay! '"
eval(instructions)

would yield:

odelay! odelay! odelay! odelay! odelay!

I'd still like to have it, since I could reduce job_state_change to one line and a table lookup if I did, but I can make do with if-chains.

The eval addon doesn't do what I'm talking about either, as far as I know, and I'm pretty sure it can't see GearSwap's variables.

"Switch-case" has nothing to do with upper- or lower-case letters, either. In most languages, instead of doing:

if fu == "bar" then
    print("Fucked up beyond all recognition, sir!")
elseif fu == "sna" then
    print("Situation normal--all fucked up, sir!")
elseif fu == "kung" then
    print("That cat was fast as lightning, sir!")
else
    print("I don't have a joke for this one, sir!")
end

you can just do (another Ruby example--Python inexplicably doesn't have one either)

case fu
when "bar"
    print("Fucked up beyond all recognition, sir!")
when "sna"
    print("Situation normal--all fucked up, sir!")
when "kung"
    print("That cat was fast as lightning, sir!")
else
    print("I don't have a joke for this one, sir!")
end

You may think these are the same, except with if-elseif chains, you're testing the same condition multiple times, which reduces performance dramatically--especially if you perform further tests inside. With a switch-case, you test the same condition exactly once.

Bro, do you even code?

[dlsmd]

this explains it more
http://lua-users.org/wiki/SwitchStatement

eval (what lua ver im not sure)
http://redis.io/commands/EVAL
but this exists in the eval addon i think

[Jeanne Renault]

this explains it more
http://lua-users.org/wiki/SwitchStatement

Yeah, I was looking at that earlier today while I worked on my substitute. None of the examples in there are remotely practical.

Note that this works, but trashes the gc with a function closure each time the switch is used (as do most of the examples on this page). Still, i like the way it works. Just don't use it in real life --PeterPrade

eval
http://redis.io/commands/EVAL

Redis is a database thing with its own Lua interpreter. EVAL and eval() are two completely different ideas, and I've never understood why databases are so loud.

[Byrthnoth]

First off, Lua and XML aren't directly comparable because Lua is an actual scripting language and XML is a format for data. When comparing structures to structures, XML is unarguably less complex than a Lua table. It's only possible to convert a fairly small subset of Lua tables to XML, but you can convert all standard XML documents to Lua Tables.

So...
* Are Lua Tables simpler than XML? No.

* Is it easier to write functioning code in Lua than to code in a purpose-made language that uses non-standard XML formatting as a basis? Probably, unless you already know the purpose-made language and it doesn't bother you how terribly inefficient it is.

As for switch: http://lua-users.org/wiki/SwitchStatement


I'll expose LoadString when I get home and fix one other bug on the -dev client. Also, ftr, "//gs debugmode" opens up the "//gs eval ___" command, which will be executed in the top-level environment (not your user environment). Also, the eval addon exists if you're just interested in testing out general Lua things.

[Jeanne Renault]

First off, Lua and XML aren't directly comparable because Lua is an actual scripting language and XML is a format for data. When comparing structures to structures, XML is unarguably less complex than a Lua table. It's only possible to convert a fairly small subset of Lua tables to XML, but you can convert all standard XML documents to Lua Tables.

So...
* Are Lua Tables simpler than XML? No.

* Is it easier to write functioning code in Lua than to code in a purpose-made language that uses non-standard XML formatting as a basis? Probably, unless you already know the purpose-made language and it doesn't bother you how terribly inefficient it is.

If you don't know either, it's easier to pick up XML. Although I'm kind of glad I finally switched from macros to GearSwap, all things considered, because it's nice to code again.

As for switch: http://lua-users.org/wiki/SwitchStatement

Already read through that. Aside from a few pointers in the right direction, it's almost all just proof-of-concept stuff.

I'll expose LoadString when I get home and fix one other bug on the -dev client. Also, ftr, "//gs debugmode" opens up the "//gs eval ___" command, which will be executed in the top-level environment (not your user environment).

Thanks. I'd rather not run it in debug mode on a daily basis though. I'll start writing your song in the meantime.

Also, the eval addon exists if you're just interested in testing out general Lua things.

Actually planning to use tables with the lines of code I want to execute stored as strings within them. That way it doesn't cause trouble the way storing functions in a table--like on that entry--would.

[Byrthnoth]

Honestly, we aren't on Pentium IIIs with 128MB of RAM anymore. Your Lua code is almost guaranteed to be so lightweight that inefficiency in it is negligible. I suspect that what GearSwap does before and after your code is going to take the vast majority of the processing time during every event until you approach an infinite loop in your code (which some people do).


When I'm looking for Switches with a static set of outcomes, I typically just use the "table o' functions" approach. You can see this implemented around line 1770 of addons/libs/extdata.lua