1. Structures are NOT a new datatype
First of all, structures are already implemented. We just call them
sequences now are able to change their *structure* all the time. But I dont
want to change the structure. This involves a long type check, which checks
the lengh and type and possibly the sub-type of every element in the
sequence. This all to avoid some silly mistakes. Result: nobody writes such
type checks, and just debugs through print statements and the tracer, since
the actual origin of the problem has not been found. (a wrong value in a
type, normally, would show up much later in the program, totally unrelated
to where the 'bug' is, while with a type check, the bug is caught where it
occurs, rather than where it first brakes your code ). So what _do_ I do
want ?
Two things:
* constants declared local to a sequence for slicing only.
* the ability to define a structure at once, without the need of
building it up using dynamic routines and to assign a type to each element
of a sequence. So, not a new language element. But a new feature. A new
syntax rather. A new way of doing something we already can. Why ? More
readable. Better maintainable.
The same goes for arrays. They already exist in the form of sequences. I
just want the interpreter to be so smart to read this:
type byte (integer x)
return x >= 0 and x < 256
end type
byte namespace[20] = ' '
..... to read that as...
type specific_type_for_ns (sequence s)
if length(s) != 20 then
return 0
end if
for index = 1 to 20 do
if not byte (s[index]) then
return 0
end if
end for
end type
specific_type_for_ns ns
ns = repeat (' ', 20)
----- Well, let me guess, you purist Euphorians......
You thought the second example was more readable and can be much better
optimized!
Why is there a repeat function in Euphoria, while you could just do:
sequence ms
ms = ""
for index = 1 to 20
ms = append(ms, ' ')
end for
Well, for two reasons:
- better readable (repeat (' ', 20) is much more logical)
- it can be optimized enormously.
And for the same two reasons I want arrays & structures, yet now these
arguments are considered insufficent!
Or is the real difference, that C does not have a repeat statement ?
What the hell does C got to do with the discussion anyway ?
Ralf
