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World: r3wp

[Core] Discuss core issues

[unknown: 5]
23-Feb-2009
[12647x2]
A gave the link because the one on my computer actually has the == 
symbol  instead.
I will probably update the website one later.  Still testing some 
other modifications to the function.
Dockimbel
23-Feb-2009
[12649]
>> a: 'test
== test
>> :a == make lit-word! :a
== false
>> :a = make lit-word! :a
== true
Henrik
23-Feb-2009
[12650]
Doc, the problem is that Paul never actually passes a lit-word to 
the function, so he can't test for strict-equal?. It just happens 
to work the way he wants for lit-words.
[unknown: 5]
23-Feb-2009
[12651x2]
>> as-lit-word? 'test
== true
See doc - that is with the strict equal.
Dockimbel
23-Feb-2009
[12653]
What does mean the resulting value of as-lit-word? That no error 
happened? What's the point?
[unknown: 5]
23-Feb-2009
[12654]
gotta call in for unemployment be back in awhile depending on when 
i get thru on the phone.
Dockimbel
23-Feb-2009
[12655x2]
Henrik: yeah I see now what's he is doing. The function just returns 
true for word! values passed as argument. I still don't see the point...looks 
like Paul is chasing windmills.
Paul, in your examples : as-lit-word? test is equal to : as-lit-word? 
1. Functions arguments are evaluated before the function is called 
 except if the functions arguments are defined as lit-word! in the 
specification block.
BrianH
23-Feb-2009
[12657]
Paul, your LIT-WORD? function returns true if passed a word! value, 
which breaks it.
Geomol
23-Feb-2009
[12658]
>> a: 'test
== test
>> type? a
== word!
>> type? :a
== word!
>> a: to lit-word! 'test
== 'test
>> type? a              
== word!
>> type? :a             
== lit-word!

As I see it, 'test gets evaluated to a word.
BrianH
23-Feb-2009
[12659]
LIT-WORD? needs to return false for values of other word types. That 
is its job.
Geomol
23-Feb-2009
[12660x2]
Agree.
And that is what it does, right? So no problem there?
[unknown: 5]
23-Feb-2009
[12662x5]
back.  ok it only took like 35 redial attempts to get through the 
Illinois unemployment claims service this week - unbelievable.
Ok, let me check it out
Doc, I'm testing to see if a word behaves like a lit-word.
That is all my function does.
BrianH, it doesn't break.  My function is not a replacement for lit-word? 
function.
BrianH
23-Feb-2009
[12667]
Nice to hear. Interestingly enough, you can write code in R3 without 
lit-word!, get-word! or set-word! values in the code. Not R2 though.
[unknown: 5]
23-Feb-2009
[12668x2]
Doc, the reason in the example above that mine returned true was 
because it matched the error.  But that is what I want because it 
still indicates that the word behaved in a manner of a lit-word.
That is why the function is called as-lit-word.  I changed it yesterday 
to get rid of this idea that it is matching a lit-word.
BrianH
23-Feb-2009
[12670x2]
Just add one function:


quote: func [
	"Returns the value passed to it without evaluation."
	:value [any-type!]
] [
	:value
]


And you can pretend that there are no lit-word!, get-word! or set-word! 
types. It needs R3's get-word! parameter semantics though.
(sorry for the formatting of that last message)
[unknown: 5]
23-Feb-2009
[12672x2]
I'll look into that Brian.  I don't do much with R3 right now.
Since were talking about R3, do you really need a true? function?
Henrik
23-Feb-2009
[12674]
BrianH, what exactly does the :value do in function header? What 
is passed?
[unknown: 5]
23-Feb-2009
[12675]
isn't make logic! enough?
BrianH
23-Feb-2009
[12676]
Yes, you need TRUE?. Make logic! isn't the same thing.
[unknown: 5]
23-Feb-2009
[12677]
Tell me how they are different.
Henrik
23-Feb-2009
[12678]
looking at TRUE?, it seems to have been added for readability. I 
missed it sometimes in R2.
BrianH
23-Feb-2009
[12679]
>> make logic! 0
== false
>> true? 0
== true
[unknown: 5]
23-Feb-2009
[12680]
I used make logic! mostely for the TRUE? effect in R2.
BrianH
23-Feb-2009
[12681]
I use TRUE?. That was copied from R2.
[unknown: 5]
23-Feb-2009
[12682]
Yeah but I don't need True? in that case if I have make logic!
Henrik
23-Feb-2009
[12683]
BrianH, interesting. Why is there difference? (sorry for all the 
questions)
[unknown: 5]
23-Feb-2009
[12684x2]
it was copied from r2?
make logic! works like C code.
BrianH
23-Feb-2009
[12686]
I've backported most of R3 to R2.
[unknown: 5]
23-Feb-2009
[12687x2]
I guess, I see the need for true? to be extremely limited.
I only bring it up because these are things I'm concerned about in 
R3.
Henrik
23-Feb-2009
[12689]
TRUE? is very useful in case of PICK.
[unknown: 5]
23-Feb-2009
[12690]
make logic! works in pick also
BrianH
23-Feb-2009
[12691x2]
Paul, you have answered Henrik's question: make logic! works like 
C code, returning true when C would. TRUE? returns true when REBOL 
would treat it as true, not C. TRUE? is useful for AND, OR and XOR 
as well.
It was Carl's function, and he *needs* it for his code, so TRUE? 
will definitely be a mezzanine, not a library function.
Geomol
23-Feb-2009
[12693]
So in R3, zero is true and other than zero is false? I remember something 
about this. Why was it made this way?
BrianH
23-Feb-2009
[12694]
Because 0 being false only makes sense for languages without a boolean 
type (logic! in REBOL).
Henrik
23-Feb-2009
[12695]
I think TRUE? provides equivalent evaluation to TRUE or FALSE in 
the case for IF and EITHER. Often you won't need to convert some 
type to logic! in order to evaluate it with IF or EITHER, but TRUE? 
allows you to display what IF and EITHER would evaluate to and it's 
necessary for PICK. I did not know it was different from make logic!, 
but to me it this difference just makes TRUE? more valid and important 
in general.
[unknown: 5]
23-Feb-2009
[12696]
So essentially true? only reports false when it meets a an actual 
false.