[JW Lua] Automatic float to integer conversion ... Lua 5.3 ?!

[Jan Angermüller]

Probably this is due to a change in Lua 5.3:
the chapter on integer/float conversion is new ( 
http://www.lua.org/manual/5.3/manual.html#3.4.3 ) and didn't exist for 
Lua 5.2.
It states:
"The conversion from float to integer checks whether the float has an 
*exact *representation as an integer (that is, the float has an integral 
value and it is in the range of integer representation). If it does, 
that representation is the result. Otherwise, the conversion *fails*."

Lesson learned:
*Don't assign float types to properties that expect integers in Lua 5.3.* *
They will not be automatically converted to integers anymore.*

This document gives a good overview of the new integer/float handling in 
Lua 5.3:
http://www.lua.org/wshop14/Ierusalimschy.pdf

So it seems that I will have a lot of fails now...
Bad luck then ... at least it leads to a cleaner code in the end.

Jan

Am 10.11.2015 um 11:08 schrieb Jan Angermüller:
> Jari,
>
> I am trying to make my scripts compatible with v.40/v.42 and get lots 
> of bad argument errors as Charles described some days ago ("Strange 
> Error Message"-thread), although with different descriptions, for example:
> bad argument #2 to '?' (number has no integer representation)
> And in my case*these errors have not occured when running the scripts 
> in previous versions of JW Lua.*
>
> For example:
> (a is an FCArticulationDef)
> a.MainHandleVerticalOffset=a.MainHandleVerticalOffset+vertoffset
> It used to work fine for any vertoffset value, even with vertoffset 
> being a float type.
> Now it throws the error message above WITHOUT the code line and 
> requires an explicit integer conversion to work:
> a.MainHandleVerticalOffset=a.MainHandleVerticalOffset+math.floor(vertoffset)
>
> Although the error message is technically correct (a float is not an 
> integer), the automatic type conversion used to work fine.
> That will be probably be days of work to fix in more than 30.000 lines 
> of code if you have to track down every error without a debugger.
>
> What's the reason for the new error message ? Is it a stricter parser 
> or Lua 5.3 or anything else ?
> Do you see any chance of solving that without having to rewrite all 
> the code.
> Or at least add the code line when a "Bad Argument" error is thrown ?
>
> All the best,
> Jan
>
> Am 28.10.2015 um 22:40 schrieb Charles O. Lawrence:
>>
>> Jari,
>>
>> Sometimes when running a script I get an error message like this.  
>> There is no line number nor is there a red marker at any source 
>> line.  It makes locating the problem rather difficult in a large 
>> script.  Any ideas? Beta 0.42
>>
>> bad argument #2 to '?' (number expected, got boolean)
>>
>> Thanks,Charles
>>
>> Sorry, I left off the subject
>>
>>
>>
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>
>
>
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