World: r3wp
[Core] Discuss core issues
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[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. |
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