OpenEuphoria

Re: Stupid Newbie-sounding question.

• Posted by "Patrick Barnes" <mistertrik at hotmail.com> Jun 01, 2004
• 578 views

>From: Robert Craig <guest at RapidEuphoria.com>
>Subject: Re: Stupid Newbie-sounding question.
>This idea has come up before.
>I haven't ruled it out.
>I was quite interested in this a few years ago.
>As I recall, the thing that made me lose some
>interest was the fear that few people
>would use it, and it wouldn't provide a great deal
>of benefit to those who did use it. It would
>also make the language more complicated,
>not to mention verbose.
>
>In other languages, you need types in order to
>define the layout of your data in memory.
>In Euphoria, a type is just a documentation
>and debugging aid, and few people seem to
>bother defining them.
>
Um, that's like saying "I don't need to replace the broken bicycle, no one 
is using it"...

The main issue with Euphoria's sequences is that they're so damn flexible 
that it can be confusing!
Issue #1:
function myFunc(sequence r1, sequence r2, sequence r3)

Okay Rob... What sort of structure do these sequences have to have? I don't 
know! If we had the ability to use stronger typing, then function 
myFunc(text_picture r1, string r2, flag_list r3) would make a lot more 
sense. I could go and look at the type declaration, and figure out what to 
pass to the function.
People don't use the types like this at the moment because it's so damn 
computationally expensive for sequences.

Issue #2:
Run-time slicing and sequence errors are my main cause of problems. The 
primary error I make is missing a set of braces around a concatenation 
command....
type vector(sequence s)
   return length(s) = 2 and atom(s[1]) and atom(s[2])
end type
type vector_list(sequence of vector s)
   return 1
end type
vector_list vectors
vectors = getVectors()
Say I wanted to add a vector to that list (and I'm not quite paying enough 
attention)
vectors &= NewVector(30, 20)

Hmm... Unbeknownst to me, the last two elements of vector are now 30 and 
20... not the last element being {30,20} like i'd hoped.

Unfortunately, I only find out when I try to reference it, which may be a 
long way from this error. At least with differential checking, an error 
would show up at that point of error, and I can fix it quicker.




While we're talking about types, it would be nice if:
Should the checked variable be an incompatible type with the parameter, it 
will just return 0, not crash the interpreter:
type myStruct (sequence s)
    if -------- return 1
    else return 0
end type

object x
...
x = 0
...
if myStruct(x) then return 1 end if
...
This crashes.

That would actually help "of"s case.

I think that having types like this would make the language *easier* to 
understand, not more complex. Especially, it would make someone elses code 
easier to read.
MrTrick