[Unity] very strange lua return values

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Escaped Ape

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Posted: 30th Mar 2007 18:57 Edited at: 30th Mar 2007 20:19

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well, the following code-snippet produces an output of:
0
1.10000002384
1

+ Code Snippet

err=lua execute("function test() return 1,1.1,'test' end")
lua set function "test",0,3
lua call
print lua return int()
print lua return float()
print lua return string()
wait key

i tried to put the function in a lua file, but it's the same.
i fiddled around with the return values and everything - allways very strange results.
My copy of the lua dll is the newst v. 3.0 and i got 1.063 update of dbpro.

EDIT: When i only return one value it returns the correct result (1)
The problem only seems to occur with multiple return values

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Torrey

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Posted: 31st Mar 2007 02:27 Edited at: 31st Mar 2007 02:28

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This isn't a bug from what I can see. Think of the multiple return like a stack of papers. In your example code you have 3 papers. You put down 1 first, then lay 1.1 on top of the first one, and then lastly you put "test" on top of the last one. Now when you go to remove those items from the stack, you start with the top most one, and that would be "test".

I guess a term for that method would be LIFO (last in first out). So for your example just do this:

+ Code Snippet

err=lua execute("function test() return 1,1.1,'test' end")
lua set function "test",0,3
lua call
print lua return string()
print lua return float()
print lua return int()
wait key

Then everything should come out alright. Doesn't it?

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Escaped Ape

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Posted: 31st Mar 2007 02:52 Edited at: 31st Mar 2007 04:28

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Sadly no.

I also thought about the stack thing, but the manual describes it like the way i wrote the code above.
Your code returns
test
0
1

EDIT: when i only use one variable type to return (3 times a string or 3 times an int) the values are correct...

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Posted: 31st Mar 2007 18:24

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any other unity user who experience this problem as well?
please don't tell me that my case is hopeless...

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Posted: 1st Apr 2007 18:08

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i hate multi-postings, but i really need somebodys help here..please.
this problem is not a tiny thing i can go round, it keeps me from using unity

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dark coder

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Posted: 2nd Apr 2007 15:04

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This is correct, because floats aren't stored like Integers or Dwords, they are fractions and so you cannot have exactly 1.1 or so I'm told, some values like 1.5 may work, however things like your 1.1 or 5.4817 will not display exactly the same, also this is faster than having accurate floats as floats are probably the most used data type in game programming so I see no problems.

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Escaped Ape

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Posted: 2nd Apr 2007 16:56 Edited at: 2nd Apr 2007 17:30

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well i don't know if you got my problem.
my problem is not the 1.10000002384 instead of 1.1, my problem is that this

+ Code Snippet

 
0
1.10000002384
1

is displayed instead of

+ Code Snippet

test
1.10000002384
1

this.
this IS a problem, because the string i wanted to return is 0.
or in torreys snippet

+ Code Snippet

test
0
1

instead of

+ Code Snippet

test
1.1
1

EDIT: I have attached a little test program, which simply calls the function "test()" of the included lua file and prints its results.
It would be very cool, if some of you could test it and post the results here.

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David T

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Posted: 6th Apr 2007 23:29

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Quote: "EDIT: when i only use one variable type to return (3 times a string or 3 times an int) the values are correct..."

Indicated that there isn't something wrong with the code that fetches strings / ints / floats from the stack. Good.

Try something like this:

+ Code Snippet

(call function)

while lua next()
print "I: ";lua return int()
endwhile

(call function again)

while lua next()
print "F: ";lua return float()
endwhile

(call function again)

while lua next()
print "S: ";lua return string()
endwhile

See what sort of data comes out, whether all the data comes out, and what order it is. You should get something like (assuming you return 1,1.1,"test")

0
1
1

0.000000
1.100001
1.000001

test
0
0

Post what you get.

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Escaped Ape

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Posted: 7th Apr 2007 00:02 Edited at: 7th Apr 2007 00:11

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first of all using the command "lua next()" to return the stack values produces no output in my case.
I used the following code:

+ Code Snippet

err=lua execute("function test() return 1,1.1,'test' end")
lua set function "test",0,3
lua call

for x=1 to 3
print "I: ";lua return int()
next x


lua set function "test",0,3
lua call

for x=1 to 3
print "F: ";lua return float()
next x

lua set function "test",0,3
lua call

for x=1 to 3
print "S: ";lua return string()
next x

wait key

and got the results:
0
1
1

0
1.1
1

test
test
test

And this is what works:

+ Code Snippet

err=lua execute("function test() return 1.1,1.2,1.3 end")
lua set function "test",0,3
lua call
print lua return float()
print lua return float()
print lua return float()
wait key

output:
1.3
1.2
1.1

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Posted: 9th Apr 2007 13:10

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So? Anything I can do?

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Escaped Ape

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Posted: 12th Apr 2007 00:53

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another bump..i really want to use that set of commands

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Bug Reports / [Unity] very strange lua return values