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World: r3wp

[Core] Discuss core issues

BrianH
8-Oct-2011
[2362]
Well, you can't use % in SQL and can't use ? in English (and some 
other european languages). If we want to code to be more flexible, 
an escape char option would have low overhead for a lot of benefit.
GrahamC
8-Oct-2011
[2363]
substitute/with
BrianH
8-Oct-2011
[2364]
That would be in keeping with how /with is used in other functions.
Ladislav
8-Oct-2011
[2365x2]
I suggested the #"%" character as an escape, but, Cyphre is right, 
that it is, in fact, not needed.
For example, if the #"%" were handled as an escape character, you 
could write

["%%"]


to obtain the "%" string, but the current version allows you to write 
just 

["%"]
GrahamC
8-Oct-2011
[2367]
So, how do you prevent %1 from being substituted?
Ladislav
8-Oct-2011
[2368]
I do not need to, if I want to obtain %1 somewhere, I can write:

["this is a string containing '%1'" "%1"]

, and I get it (although substituted)
BrianH
8-Oct-2011
[2369x2]
Yup, it's only needed if you want SUBSTITUTE to be used for more 
than just translated strings. And something like SUBSTITUTE using 
? is only needed for SQL dialects that we implement ourselves, not 
for server access where they do their own parsing of prepared statements.
I'm OK with not having a /with, but I'm sold on having an APPLY-style 
/only option.
GrahamC
8-Oct-2011
[2371]
That sounds tricky ... if you're reading two input streams .. to 
substitute ... you need to know when a %n is intended not to be replaced
BrianH
8-Oct-2011
[2372]
What if "%%" was always interpreted as "%"? Then the way that you 
signify %n as not being a replacement is to write it as %%n.
GrahamC
8-Oct-2011
[2373x2]
This is what happens in MS dos
shell
BrianH
8-Oct-2011
[2375x2]
Yup.
The main advantage to APPLY reducing its argument is that it doesn't 
necessarily have to allocate an intermediate block. This might be 
tricky though if you want to implement SUBSTITUTE as a command. Can 
you DO/next in a command?
GrahamC
8-Oct-2011
[2377]
And I guess my next question is, do you really need "n" ?  Why not 
prepare the arguments in order and just use them as in SQL dialect?
Ladislav
8-Oct-2011
[2378]
The current proposal allows me to write:

["%%1" "%1"]


to obtain the "%%1" string. With your proposal I would need to write 
it as

["%%%%1"]

, so, I do not think I gain any advantage.
GrahamC
8-Oct-2011
[2379]
Yes, it's more flexible
Ladislav
8-Oct-2011
[2380]
Why not prepare the arguments in order
 - that is not suitable for translation
BrianH
8-Oct-2011
[2381]
Graham, the %n method supports switching template strings between 
languages with different sentence ordering.
Ladislav
8-Oct-2011
[2382]
(thranslation should be able to adjust the order according to the 
language requirements)
GrahamC
8-Oct-2011
[2383]
Sounds then the cases are quite different and should have different 
functions
BrianH
8-Oct-2011
[2384x3]
Ladislav, the advantage would be that you don't have to allocate 
a substitution argument for that % escaping, especially if some of 
your template strings might need a %1 in them and others might not.
I am thinking of the code-generation posibilities, where instead 
of Russian you are generating ASP or something.
Or RSP if you like.
Ladislav
8-Oct-2011
[2387]
the advantage would be that you don't have to allocate a substitution 
argument for that % escaping

 - yes, understood, I was originally for that alternative, but, Cyphre 
 convinced me, that for human writers, actualy the substitution is 
 more readable
BrianH
8-Oct-2011
[2388]
Ah, sticking to the natural language translation usage model, even 
though you are allocating a more generally applicable name to the 
function.
GrahamC
8-Oct-2011
[2389]
substitute ( "%1" "translate" )
Ladislav
8-Oct-2011
[2390x2]
Well, yes, the name may be conflicting, sure
But, "translate" is not a good name, since the translation is what 
is being performed as well, besides the substitution
BrianH
8-Oct-2011
[2392]
Well, given my current business needs I would use SUBSTITUTE more 
for code generation than for translation, but it would be useful 
for generating English as well.
Ladislav
9-Oct-2011
[2393x3]
Sure, I expect there *are* other uses. As for the %% case, I am still 
not sure, it might be intersting to know what would Robert prefer.
In general, I do not expect the #"%" character to be contained in 
the texts being followed by a digit. At least not frequently enough 
to normally matter.
But, sure, in strings that are not meant to communicate something 
to humans, the frequency of "%" may be higher.
Ladislav
10-Oct-2011
[2396x3]
Hi, I found the following text part in the Replacement article: "ENLINE 
any-block!,". Forgive my ignorance, please. What exactly is ENLINE 
meant to do in case its SERIES argument is a block?
I am especially curious, if it really qualifies as non-modifying 
function in that case.
aha, nevermind, I just used some tests to find out what it does
BrianH
10-Oct-2011
[2399]
I really wish the ENLINE/with ticket would be implemented. I could 
use this function daily.
Ladislav
12-Oct-2011
[2400x2]
In R3 we have got the

    system/state/last-error


, which is great for convenience. Is there a corresponding variable 
in R2?
If it does not, it would be great to have this feature backported...
Geomol
12-Oct-2011
[2402]
Today's Moment of REBOL Zen:

>> s: "A"
== "A"
>> lowercase s
== "a"
>> s
== "a"
>> c: #"A"
== #"A"
>> lowercase c
== #"a"
>> c
== #"A"
Ladislav
12-Oct-2011
[2403x2]
:-)
I hope you know why?
Geomol
12-Oct-2011
[2405]
Yes, I do.

And I'm thinking, if it would be an idea to let functions like that 
take word arguments handling them like call-by-reference. Then it 
would be possible to change chars too.
Endo
12-Oct-2011
[2406]
You mean also
>> i: 5
== 5
>> multiply i 4
== 20
>> i
== 20 (?)
Geomol
12-Oct-2011
[2407x2]
That would be
	multiply 'i 4

then. Maybe not too useful in that case. Or though, the ++ operation 
(function) could use this too. Which then reminds me, that NEXT should 
be used for what ++ does. :)
There was a discusson in Carl's blog about this long time ago.
Endo
12-Oct-2011
[2409x2]
move-next 'series
 looks ok but multiply looks weird.
but ++ already works for series as you say.
++ : "Increment an integer or series index."
Geomol
12-Oct-2011
[2411]
Has anyone said the following before?

call-by-word