OpenEuphoria

Re: Source changes

• Posted by Derek Parnell <ddparnell at bigpond.co?> Jul 02, 2007
• 622 views

Alan Oxley wrote:
> 
> Derek wrote ..
> This set will attempt to convert the text to the requested format, but if
> they are unable to they do not fail, instead they return zero.
> 
> Derek, how about always returning a sequence with the first atom being
> the return code? Otherwise I would not know the difference if the data to
> be evaluated resolved to zero, and a function failure.

I've catered for this too in that all the 'to_xxx' routines will have an
equivalent 'conv_xxx' routine. The 'to_xxx' is designed to always return a number
because there are situations in which this is acceptable to do, and the
'conv_xxx' returns a sequence if it fails and a number if it succeeds.

The usage of 'conv_xxx' depends on what the application expects to be in the
text. For example...

   object result
   sequence inp

   inp = getField(fldCosting) --> "$123.45 per Item"
   result = conv_atom(inp)    --> {123.45,8} 
   if sequence(result) then
        cost = result[1]
        description = inp[result[2]..$]
   else
        cost = result
        description = ""
   end if

And in another usage it might be more like ...

   result = {}
   while sequence(result) do
     inp = ask_user("Enter your age") --> "I'm 19 years old"
     result = conv_integer(inp)    --> {0,1} 
     if sequence(result) then
        msg("You must enter your age as a simple number (of years)")
     else
        user_age = result
     end if
   end while

or using the 'to_xxx' routine:
   result = 0
   while result < 1 or result > 99 do
     inp = ask_user("Enter your age") --> "I'm 19 years old"
     result = to_number(inp)    --> 0
     if result < 1 or result > 99 then
        msg("You must enter your age as a simple number between 1 and 99")
     else
        user_age = result
     end if
   end while

But note that to_digits() would have returned 19 because it discards all
non-digits.

-- 
Derek Parnell
Melbourne, Australia
Skype name: derek.j.parnell