OpenEuphoria

Re: From a newbie

• Posted by Ralf Nieuwenhuijsen <nieuwen at XS4ALL.NL> Sep 20, 1998
• 627 views

>Hi,
>I am a very newbie to Euphoria - I tried it since I need free data
structure in my project. Euphoria succeeded! I've written working Code
Generator Genarator within a day.


Welcome,

>1. Conditional expressions are fully evaluated. Is it an Euphoria bug?
>I never use this language "feature". I know that it is optional in Borland
Pascal/Delphi and in Java but I prefer (and don't know anybody who don't)
shortcut evaluation. It's faster and more usable. For example if you run
this in Euphoria:

Euphoria 2 will short-circuit, and give a warning message with those
programs where it could led to a problem, when the programmer is not
consider the short-circuiting..

>2. Is there any possibility to change value of non-global variable (e.g. an
argument) inside function/procedure?

Thankfully not at all, its much cleaner this way.
The only way to do this is to use the return value, thankfully you can just
make a sequence out of it:

function myfunc (sequence s, integer x)
    s = s + x
    x = x * 2
    return {s, x}
end function


Its the only way, however, if you use David Cuny's new preproccesor you can
use dots for this use:

So you could make a function call like this one:

function myfunc (sequence s, integer x)
    .. bla bla bla..
    return s
end function

my_seq = myfunc (my_seq, 45)

Look like this:

my seq.myfunc (45)

>Euphoria language extension suggestions:
>
>1. If answer for Q2 is "No" make it possible - in/out arguments.
>in - argument is an input (default)
>out - argument is an output
>in out - both as input and output

I disagree, the programmer using the function wouldnt preciously know which
variables could or could not have been altered.
However, a very nice replacement trick for this is: (something I would like
to see added)

{ name, addres, phone } = lookup_db (name)

See ? Here the programmer does see what is altered, yet he doesnt have to
split the sequence himself like:

temp = lookup_db (name)
name = temp[1]
addres = temp[2]
phone = temp[3]


Which I agree is a bit ugly..

>2. Structured gotos (as in Java) and exceptions implementation.


I find them a bit scary.. but there are cases they are handy..

What about this one, Robert ?

exit (3) -- jump out three levels

Too often, do I need to use a flag variable to mark that Im jumping out of
more than one loop.

>3. "dot" operator. For example:
>const
>  fX = 1,
>  fY = 2
>sequence p
>p.fX = 0 -- means p[fX] = 0
>p.fY = 0 -- means p[fY] = 0
>-- It makes code more readable.


Structures are under consideration, I suspect. many people want this, and no
one is against them.

>4. All preprocessor's (pp) extensions.


Agree with you on that. However, the two dot-notations would make a bit of
confusement.
Actually, the dot preproccesor is not clean enough for euphoria I think.
But the for each in.. is brilliant..and allows great clean optimizing..

So, Robert, had a nice vacation ?
A serieus suggestion list here, any one any implentation suggestions ?

Ralf Nieuwenhuijsen
nieuwen at xs4all.nl