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World: r4wp

[Rebol School] REBOL School

MarcS
12-Oct-2012
[1372]
ladislav: i meant when not binding inside a block
Ladislav
12-Oct-2012
[1373x2]
What does it have in common with "binding"?
BTW, the examples both use binding in a way
MarcS
12-Oct-2012
[1375]
i just mean assigment
Ladislav
12-Oct-2012
[1376]
actually, you cannot use assignment "outside of a block" in REBOL
MarcS
12-Oct-2012
[1377]
henrik: but - http://pastebin.com/3s30AxY4
Ladislav
12-Oct-2012
[1378]
(there is always a block somewhere)
MarcS
12-Oct-2012
[1379x2]
ladislav: sorry, i'm using terminology sloppily
i guess: assigning to a word in the global (system?) context
Ladislav
12-Oct-2012
[1381x2]
that is what both the examples above do
(the 'A word is not local)
MarcS
12-Oct-2012
[1383]
yes, but the other part was: not inside a(nother literal) block
Ladislav
12-Oct-2012
[1384]
That cannot be done.
MarcS
12-Oct-2012
[1385]
okay, not inside another explicit literal block
Henrik
12-Oct-2012
[1386]
MarcS, yes, now you are in X and Y pointing at the same context.
Ladislav
12-Oct-2012
[1387]
In REBOL, there is always a block somewhere
MarcS
12-Oct-2012
[1388x2]
henrik: oh, right
ladislav: yes, okay - i'm just saying that i understand the pitfalls 
of not copying when you're re-entering a block (be it a loop, function, 
etc. body)
Ladislav
12-Oct-2012
[1390]
for example, something like:

do "a: []"

first "converts" the string to a block
MarcS
12-Oct-2012
[1391]
but where i'm assigning to a "global" (which i understand is just 
another context) outside of an explicit (one i write myself) literal 
block, are there pitfalls in not using copy
Henrik
12-Oct-2012
[1392]
yes, if you are running the same script several times in the same 
console.
MarcS
12-Oct-2012
[1393x4]
also, i get that x: [ append [] 1 ] then 'do x do x' differs from 
x: [ append copy [] 1 ] 'do x do x'
henrik: so if i load the script, then do it, rather than doing the 
file?
makes sense, hadn't considered that
so: best practice is to consider everything to be inside a block, 
and hence copy even toplevel literals?
Henrik
12-Oct-2012
[1397]
not even needed. you may DO the same script several times for the 
same effect.
Ladislav
12-Oct-2012
[1398x2]
in the

    a: []


it is so, that if you do not "reuse" the literal block then it does 
not matter whether you copy or not
by "reuse" I mean if you do not keep the code and reevaluate it once 
again
MarcS
12-Oct-2012
[1400x4]
right
but of course,
>> x: load %foo.r 
== [
    foo: [] 
    append foo 1
]
>> do x
== [1]
>> do x
== [1 1]
>> foo
== [1 1]
which was henrik's point
Henrik
12-Oct-2012
[1404]
actually not
MarcS
12-Oct-2012
[1405]
oh!
Ladislav
12-Oct-2012
[1406]
and by "keep the code" I mean "keep the code as a block", if you 
keep it as a string then it does not matter
Henrik
12-Oct-2012
[1407]
do %foo.r
do %foo.r

will produce something you may not intend.
MarcS
12-Oct-2012
[1408x4]
well, if there are side effects, sure
but with the above, i get the anticipated result,
>> do %foo.r
Script: "Untitled" (none)
== [1]
>> do %foo.r
Script: "Untitled" (none)
== [1]
>> foo
== [1]
ladislav: yep, understood
Henrik
12-Oct-2012
[1412]
sorry, MarcS. you are right again. I better take a nap...
MarcS
12-Oct-2012
[1413x2]
so to get back to pitfall vs. stylistic - i notice that carl's scripts 
(makedoc, blog) tend not to copy 'global' literals
whereas, for example, the source for vanilla does
Ladislav
12-Oct-2012
[1415]
However, when writing something like:

a: []


into a file, you may not be totally sure that somebody does not LOAD 
your code and try to evaluate it twice....
MarcS
12-Oct-2012
[1416x2]
yep
so unless you're certain (!) that that won't occur, better to be 
safe and copy?
Ladislav
12-Oct-2012
[1418]
Yes, copy looks safer....
MarcS
12-Oct-2012
[1419]
thanks for the help
Endo
17-Oct-2012
[1420x2]
Henrik: I've registered on http://hmkdesign.dkBugs database (curecode), 
I got an error when I create a new account but I think it created 
my user. Can you check it please?
My username is "endo".
I've setup a new Cheyenne (r179) with html-008.r included, playing 
with html dialect.