table.insert and string.gsub

Posted by Mahony on Tue 23 Sep 2014 12:46 PM — 6 posts, 22,013 views.

Mahony Tue 23 Sep 2014 12:46 PM #0

I'm trying to insert a string that I need to adjust before entering.


%1 is amulet aardwolf                            |

t = {}
table.insert(t, "string.gsub("%1","( +)|","")")

I get error
[string "Trigger: "]:2: ')' expected near 'amulet'

I read lue table details and help for lua tables and searched forum...

When I do it this way


%1 is amulet aardwolf                            |
aaa = string.gsub("%1","( +)|","")
t = {}
table.insert(t, "aaa")

it works. But I don't want to use another variable and I think it must work the first way... somehow

Fiendish USA Global Moderator Tue 23 Sep 2014 01:22 PM #1

Quote:
But I don't want to use another variable

That is a bad reason.

Anyway, in your first attempt you should change

table.insert(t, "string.gsub("%1","( +)|","")")

table.insert(t, string.gsub("%1","( +)|",""))

Also, your second attempt doesn't actually work.
You want

table.insert(t, aaa)

not

table.insert(t, "aaa")

Mahony Tue 23 Sep 2014 01:43 PM #2

here is what i get if I omit the quotes


table.insert(t, string.gsub("%1","( +)|",""))

Run-time error
World: Aardwolf
Immediate execution
[string "Trigger: "]:6: bad argument #2 to 'insert' (number expected, got string)
stack traceback:
        [C]: in function 'insert'
        [string "Trigger: "]:6: in main chunk

I played with all sorts of quotes and didn't get the result.. :(
You are right with the second part


table.insert(t, aaa)

is correct and works.

Fiendish USA Global Moderator Tue 23 Sep 2014 06:46 PM #3

Mahony said:

here is what i get if I omit the quotes


table.insert(t, string.gsub("%1","( +)|",""))

Run-time error
World: Aardwolf
Immediate execution
[string "Trigger: "]:6: bad argument #2 to 'insert' (number expected, got string)
stack traceback:
        [C]: in function 'insert'
        [string "Trigger: "]:6: in main chunk

Ah...of course. Sorry, I wasn't thinking. gsub returns multiple values. So you can't directly pass it to table.insert. What the second one is doing is implicitly dropping the second return value from gsub.

Nick Gammon Australia Forum Administrator Tue 23 Sep 2014 08:33 PM #4

~~What's your regexp doing? You can't use the "|" in Lua regexps (unless you are looking for "|"). In PCRE regexeps the "|" symbol means "or".~~


foo = "amulet          aardwolf"

t = {}
table.insert(t, (string.gsub(foo," +"," ")))

require "tprint"
tprint (t)

That example removes the spaces in foo. The brackets around string.gsub forces the return of the first result only.

[EDIT] Ah I see now. Try this:


foo = "amulet aardwolf                            |"

t = {}
table.insert(t, (string.gsub(foo," +|","")))

tprint (t)

Replace foo by "%1" and it should work, eg.


t = {}
table.insert(t, (string.gsub("%1"," +|","")))

Mahony Tue 23 Sep 2014 09:41 PM #5

It works! :) Thank you Nick