OpenEuphoria

Danger! Type-checking & the translator

• Posted by Andy Serpa <ac at onehorseshy.com> Jan 27, 2003
• 527 views

Hello,

I know that translated programs don't do type-checking, but I assumed 
this was for built-in Euphoria types, not user-specifed types.  
Apparently I was wrong.  Take the following program:

integer z
z = 0

type test(object x)
	z = 1
	return 1
end type
test y

y = 4
? z

Now every time y is assigned a value, it has the side effect of assining 
a value to z.  Run with the interpreter, and the output is:

1

Translated, the output is 0 -- the type code is never called.


Unless I'm just doing something stupid, this is major.  Anything that 
depends on custom-types for exception handling or these type of side 
effects won't work when translated.  This breaks *LOTS* of code when 
translating, including major libraries like Mike Nelson's Diamond.  Why 
isn't this in the docs?  The translator docs say:

"Note: The translator assumes that your program has no run-time errors 
in it that would be caught by the interpreter. The translator does not 
check for: subscript out of bounds, variable not initialized, assigning 
the wrong type of data to a variable, etc. "

This goes way beyond debugging.  It should say, "You can't use custom 
types in translated programs, period."

Please tell me I'm wrong about this...