OpenEuphoria

Re: "OF" in types...

• Posted by Pete Lomax <petelomax at blueyonder.co.uk> Jun 02, 2004
• 503 views

On Thu, 03 Jun 2004 08:23:18 +1000, Patrick Barnes
<mistertrik at hotmail.com> wrote:

>Any comments on this yet?
>------------------------------------------------------------------------
>magnae clunes mihi placent, nec possum de hac re mentiri.
Martin Clunes ate my placenta, therefore I became retarded?
>------------------------------------------------------------------------

>>http://users.secsme.org.au/~prbarnes/misc/oth/type_of.txt  <-- Draft spec 
>>Please comment.
>The 'of' declaration is ONLY allowed within a type declaration, 
Any particular reason why?
type x(sequence of z)
	return 1
end type
On a previous post you said that a simple return 1 could be ignored.
That would make x y and sequence of z y exactly the same.

4/4a. I think you are on the right path there, needs a bit more
clarification, and dare I suggest examples of good and invalid?
It shouldn't be "disallow"; it should issue warnings (unless without
warning is in force around the type definition) and not be "fast" type
checking.

5.2 if assigned to a literal and {}. You are wrong there. a literal is
an object, it always needs full type checking (and it is often more
important than run-time type checking, to make sure you start off on
the right foot).
5.3 Ditto, functions only ever return an object. Of course a function
can return anything, you can easily write a function that (randomly)
returns an integer, float, or a sequence: you just *have* to treat
function returns as type object, life gets too difficult otherwise.
5.4 not a logical operation but a concat()?

6. I retract this. There is no way to make badly written types fast.
Instead, I want to be told how to write fast type checking.
You can, of course (by enclosing in "without warning") still write
slow type checking, I want to know how to write type checking which
can be left on in production code, ie that does not kill performance.
Eg a type which maintains a sum is "badly written".

7. Derek quashed this?

I am slightly worried you are overly concerned with checking the
"base", in my mind checking fewer elements is the key? The more I
think on this, everything should be done _via_ the base, just passing
the minimum number of elements...
Also, for nested types, and subscript assignments, invoking the type
checking "at the right level and no higher".

Pete