World: r3wp

http://www.tretbase.com/forum/viewtopic.php?f=8&t=30&p=141#p141

as-lit-word?: make function! [  

    "Returns logic on whether the val argument is as a lit-word! type"
    val
    ][
    not error? try [= :val make lit-word! :val]
]

You're using the wrong operator, your should be using == instead 
of = to test for datatype equality.

not error? try [== :val make lit-word! :val]

You can use that also Doc and it still works.

I have already used both in my function.

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.

>> a: 'test
== test
>> :a == make lit-word! :a
== false
>> :a = make lit-word! :a
== true

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.

>> as-lit-word? 'test
== true

See doc - that is with the strict equal.

What does mean the resulting value of as-lit-word? That no error 
happened? What's the point?

gotta call in for unemployment be back in awhile depending on when 
i get thru on the phone.

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.

Paul, your LIT-WORD? function returns true if passed a word! value, 
which breaks it.

>> 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.

LIT-WORD? needs to return false for values of other word types. That 
is its job.

Agree.

And that is what it does, right? So no problem there?

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.

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.

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.

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)

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?

BrianH, what exactly does the :value do in function header? What 
is passed?

isn't make logic! enough?

Yes, you need TRUE?. Make logic! isn't the same thing.

Tell me how they are different.

looking at TRUE?, it seems to have been added for readability. I 
missed it sometimes in R2.

>> make logic! 0
== false
>> true? 0
== true

I used make logic! mostely for the TRUE? effect in R2.

I use TRUE?. That was copied from R2.

Yeah but I don't need True? in that case if I have make logic!

BrianH, interesting. Why is there difference? (sorry for all the 
questions)

it was copied from r2?

make logic! works like C code.

I've backported most of R3 to R2.

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.

TRUE? is very useful in case of PICK.

make logic! works in pick also

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.