Run Lua code from the command line

[Vadi]

Small alias to execute lua code from the input line - import in, and do lua echo ("hi") for example. Can also display things with lua display(mytable) or lua mytable.

Note: this script is included by default with Mudlet now, you can use it as-is without installing!

[eraldo]

Nice...
Thank you for this great piece of code!

[Vadi]

Alias improved, now auto-displays if the function returned any results.

[Vadi]

Fixed v2.

[Vadi]

Updated to v4 - if a function returns 'false' as a result, it'll be displayed properly.

[Phoenix]

I use the following code - it's basically the same, except it allows multiple returns. IE, if you did lua getMainWindowSize(), this would return both the first and second values.

Code: [show] | [select all] lua

local f,e = loadstring("return "..matches[2]) 
if not f then
	f,e = assert(loadstring(matches[2])) end   
local a,b,c = f()
if a ~= nil then echo ("A:  ") display(a,nil,1) end
if b ~= nil then echo ("B:  ") display(b,nil,1) end
if c ~= nil then echo ("C:  ") display(c,nil,1) end
if e ~= nil then echo ("Er: ") display(e,nil,1) end

The reason for the exotic use of display is to tell it that it's already started... it's not at '0'. This allows it to display the first line on the same line as the A: or B: etc.

lua getMainWindowSize()
A: 1280
B: 633

[Golem]

Don't know if this will be of any use, but a more universal solution would be something like this:

Code: [show] | [select all] lua

local f,e = loadstring("return "..matches[2])
if not f then
	f,e = assert(loadstring(matches[2]))
end

local pack = function(...)
	return arg
end

local r = pack(f())
if #r == 1 then
 display(r[1]) 
elseif #r > 1 then
 echo("Multiple returns: ")
 display(r)
end

[Phoenix]

Interesting - what is the pack() function doing with f()? Would not r = {f()} be more simple? I've long since modified my lua code alias to do that, just never updated this post...

[Golem]

Truth be told, it probably is. pack() was just a mental exercise in creating an inverse function to the unpack() function.

[Phoenix]

... I see. pack() is interesting, looks like it basically just wraps {} around the arguments, and throws in a key of 'n' equal to the number of arguments. I wonder how it compares speedwise to r = {f()}...