OpenEuphoria

Re: Comparing Sequences

• Posted by David Cuny <dcuny at LANSET.COM> Oct 06, 2000
• 698 views

Lewis Townsend wrote:

> I use '=' on sequences  rather often and
> not just for graphics.

With all these warnings that lots of code would break, I decided to take an
entirely unscientific sampling of some Euphoria code. First, since you said
you use '=' on sequence "rather often", I decided to take a look at your
submissions to see what I was missing:

    BALEN
    FNS
    LAGUI
    LEWISART
    LOOP

Of these, the construct occurs twice. In BALEN/GAMES.E/make_screen:

        dude2 = (dude = 0)

this appears to build a mask of a bitmap. In FNS/FNS.EX/fall:

          s = rand (2)
          i = (((s=1) * -1) + (s=2))

which appears to intialize a sequence to random values.

Slightly emboldened, I took a look at include files that come with Euphoria:

    DLL.E
    FILE.E
    GET.E
    GRAPHICS.E
    IMAGE.E
    MACHINE.E
    MISC.E
    MOUSE.E
    MSGBOX.E
    SAFE.E
    SORT.E
    WILDCARD.E

Of these, the idom only appears in WILDCARD.E, in lower and upper. Robert
has already submitted these as an example of the '=' operation on sequences:

    -- wildcard.e
    global function lower(object x)
    -- convert atom or sequence to lower case
        return x + (x >= 'A' and x <= 'Z') * TO_LOWER
    end function

    global function upper(object x)
    -- convert atom or sequence to upper case
        return x - (x >= 'a' and x <= 'z') * TO_LOWER
    end function

I agree with Robert's conclusion that code would break if he implemented my
suggestions. However, after looking through the code, I'm now even less
convinced that using '=' on sequences is a significant idiom in Euphoria.

-- David Cuny