OpenEuphoria

QBasic Stuff/Wish List

• Posted by "Cuny, David at DSS" <David.Cuny at DSS.CA.GOV> Sep 11, 2000
• 423 views

I finally converted my web page generator and sent it off to Robert. As
usual, it took more time to convert than I guessed it would. The code is
pretty awful, but there are some goodies I've added in to make it easier to
convert from QBasic.

[ eof ]

I've never gotten used to Euphoria sometimes returning a string, and
sometimes returning a numeric code. It's jarring, and the resulting code
moves the logic from the top of the 'while' loop and into the loop body:

   while 1 do

      o = gets( handle )
      if integer(o) then
         exit
      end if

      ...

   end while

I've coded a pair of functions to support the QBasic way of doing things:

   while not eof( handle ) do
      s = line_input( handle )
   end while

eof() is used to check for an end of file. line_input() is guaranteed to
return a sequence from the file. If it's the end of the file, it returns an
empty sequence. It would be nice (for me, anyway) if Euphoria's built-in
file routines worked with eof(). Robert wouldn't need to change their
defined behaviors, either - they could still return -1 on EOF.

[ string functions ]

I've complained a lot about Euphoria choking if a string is sliced wrong,
mainly because I'm used to how QBasic handles strings. So I coded the QBasic
string routines mid(), left() and right(). They are guaranteed to return a
sequence (if only an empty sequence). For example:

   left("12345",2) --> "12"
   left("12345",12) -> "12345"
   left("12345",0) --> ""

This makes comparisons with strings safe:

   -- check for a comment
   if equal(left(s,2), "--") then

(although writing:

   if left(s,2) = "--" then

would be even simpler!)

Finally, inspired by Python, left() and right() allow negative indexes. So
you can write:

   -- return string, less 1 character off right side
   s = left(s,-1)

instead of:

   s = s[1..length(s)-1)]


[wishlist]

I know that it might be considered bloat, but it would be Real Convenient if
Euphoria allowed C++ style comments:

   // like this

in addition to "classic" comments

  -- like this


-- David Cuny