[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Volker suggested: how about extending path syntax? a/5:10 How about these two alternatives: a/5-10 a/5..10 ? Both use reasonably common indicators which mean missing something out, which is very obvious. Andrew J Martin ICQ: 26227169 http://www.rebol.it/Valley/ http://valley.orcon.net.nz/ http://Valley.150m.com/ -- -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
As Max wrote: I love philosophy so, nothing here is personal... :-) Volker suggested: how about extending path syntax? a/5:10 How about these two alternatives: a/5-10 a/5..10 ? Both use reasonably common indicators which mean missing something out, which is very obvious. Paths are a series of values - each value in the series having a datatype. So is a/5..10 one path of length two - the second value (5..10) being a new datatype? Something like a pair? But if it is a new datatype we would want to store them in a block a: [1..3 5..10] a/5..10...oh oh. Or is a/5..10 meaning that .. is an operator with the necessary whitespace missing in which case it should be written a/5 .. 10 or perhaps even .. a/5 10 Hmm... I don't doubt that REBOL can be improved, but I've don't think I've seen any compelling suggestion on this thread yet - though I do admit, lots of innovation! :^) Then again, I still occasionally lament the removal of aggressively evaluated paths so who am I to comment?! (-: Brett. -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Hi Brett, On Monday, October 20, 2003, 8:29:41 AM, you wrote: BH So is a/5..10 one path of length two - the second value (5..10) being a new BH datatype? Something like a pair? There are two issues here that people seem to forget. First of all, REBOL is based on values, not on operators. So we are not talking about adding a new operator, we are talking about adding a new type of value, or at least adding new semantics for some existing datatype when encountered by the function interpreter. Second, there's something I don't like in the kind of semantics we are talking about: we are hiding under some kind of syntactic sugar an operation that is going to require an amount of computation that is not evident by looking at the notation itself. This is in part the case for paths too, so I'm not saying a firm no, but I'm very afraid of this kind of syntactic sugar. Regards, Gabriele. -- Gabriele Santilli [EMAIL PROTECTED] -- REBOL Programmer Amiga Group Italia sez. L'Aquila --- SOON: http://www.rebol.it/ -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
On 20-Oct-03, Brett Handley wrote: As Max wrote: I love philosophy so, nothing here is personal... :-) Volker suggested: how about extending path syntax? a/5:10 How about these two alternatives: a/5-10 a/5..10 ? Both use reasonably common indicators which mean missing something out, which is very obvious. Paths are a series of values - each value in the series having a datatype. So is a/5..10 one path of length two - the second value (5..10) being a new datatype? Something like a pair? Curiously, 5..10 is already a valid datatype... 5..10 == 5.0.10 5-10 isn't though... 5-10 ** Syntax Error: Invalid date -- 5-10 ** Near: (line 1) 5-10 If a new datatype, it'd be called range! I guess. But how to indicate first or last? Maybe... 5-10 *-10 5-* or some alternative to an asterix, though not a colon, as it'd be much too confusing in a path. But if it is a new datatype we would want to store them in a block a: [1..3 5..10] a/5..10...oh oh. Or is a/5..10 meaning that .. is an operator with the necessary whitespace missing in which case it should be written a/5 .. 10 or perhaps even .. a/5 10 Hmm... I don't doubt that REBOL can be improved, but I've don't think I've seen any compelling suggestion on this thread yet - though I do admit, lots of innovation! :^) Then again, I still occasionally lament the removal of aggressively evaluated paths so who am I to comment?! (-: Brett. -- Carl Read -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
I thought of a range datatype too, and it would pobably have its uses, but
my intent was not to promote a new type so much as to indicate a position
far more elegantly and precisely described by Gabriele.
Regards,
Brett.
- Original Message -
From: Carl Read [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Monday, October 20, 2003 8:33 PM
Subject: [REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol
versions?
On 20-Oct-03, Brett Handley wrote:
As Max wrote:
I love philosophy so, nothing here is personal... :-)
Volker suggested:
how about extending path syntax?
a/5:10
How about these two alternatives:
a/5-10
a/5..10
?
Both use reasonably common indicators which mean missing
something out,
which is very obvious.
Paths are a series of values - each value in the series having a
datatype.
So is a/5..10 one path of length two - the second value (5..10)
being a new datatype? Something like a pair?
Curiously, 5..10 is already a valid datatype...
5..10
== 5.0.10
5-10 isn't though...
5-10
** Syntax Error: Invalid date -- 5-10
** Near: (line 1) 5-10
If a new datatype, it'd be called range! I guess. But how to indicate
first or last? Maybe...
5-10
*-10
5-*
or some alternative to an asterix, though not a colon, as it'd be much
too confusing in a path.
But if it is a new datatype we would want to store them in a block
a: [1..3 5..10]
a/5..10...oh oh.
Or is a/5..10 meaning that .. is an operator with the necessary
whitespace missing in which case it should be written
a/5 .. 10
or perhaps even
.. a/5 10
Hmm...
I don't doubt that REBOL can be improved, but I've don't think I've
seen any compelling suggestion on this thread yet - though I do
admit, lots of innovation! :^)
Then again, I still occasionally lament the removal of aggressively
evaluated paths so who am I to comment?! (-:
Brett.
--
Carl Read
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[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Hi Max, MOA I love philosophy so, nothing here is personal... :-) Yes, same here. MOA a lot of the code I see from MOA the guru is hard to read for me, simply because it uses tricks I have not MOA stumbled on yet... The words are all similar, but when looking at them, they MOA seem to have no meaning. MOA have you tried going through all the view code... there is much to learn, but MOA darn some of it is almost impossible to grasp. This is one of the mindset changes I still struggle with. I used to design and code so that things were as generically-understandable as possible, at the expense of elegance. What I think about more and more with REBOL is how to make things as clear as possible to a subset of people--people that I want to communicate with. This is tough with things like reusable modules and functions that could have a wide audience and be put to use in many contexts. Rather than writing for drop-in usage everywhere, I'll allow myself to make assumptions and know that people will modify things to suit their needs. It's a whole different view, and not an easy change for me. But when I look at Carl's code in many places, that's how I interpret what he has done. Really advanced REBOL is a different language than very basic REBOL; a dialect if you will. :) MOA nothing is clear in rebol, until you've programmed in it a few months. I can only speak for myself, but I *think* programmers coming from other languages may have the hardest time with things. Even after two years, I still don't always think of things how I know I should in REBOL. One of the best tricks I have found for myself is a twist on the idea of playing turtle in Logo. I play interpreter by reading my code as a series of values and stepping through it mentally. It's fun. :) MOA My guess is that RT can make sure that if they found a path value MOA with a block in it, they'd simply understand it as a range MOA instead... isn't that what a dialect is? context specific code? ... MOA it isnt really a change, its more of an addition, but I guess you mean that MOA people creating dialects and expecting paths, would have to handle range MOA notations too, then you are right, that it causes some mishaps. But then most of MOA the code I get from this list already isn't supported in older versions of MOA rebol... especially view v1.2.3 Yes, but I guess I see it as a more sweeping change than that, because it's adding a dialect to a datatype, which has a specific lexical form, so if you do it for paths: do you do it for other datatypes; is it only valid as a complete path element; are they aggressively evaluated; does it cause other side effects; how does COMPOSE work with it (i.e. block flattening); can they be nested; do we go as far as the concept of generators in Icon, and what would that mean, etc. Maybe I just worry too much. :) Could I do stuff like this? start: 2 stop: 12 foreach ip 192.168.[1:10].1 [ ; time! values as range boundaries? foreach data read join http:// [ip /dat[(00:00):(4:30)].html] [ foreach addr data-monitor-[#a:#f[EMAIL PROTECTED] [ send addr data/[:start::stop] ; ??? syntax ] ] ] And what would be the cost in time, effort, and complexity, versus what we gain, maybe compared with writing a RANGE function that knows how to handle this stuff, but makes it an explicit dialected function? MOA don't want to look picky but MOA a: 1 MOA b: 5 MOA excerpt b [a to b] MOA I know someone will say do this: MOA excerpt b compose [(a) to (b)] Wouldn't a range notation have the same issue? A dialect is a dialect (no matter how small :). How would a range notation handle it? b/[a:b] ; aggressively evaluated. Only integer! boundaries OK? b/:[a:b] ; per current path evaluation syntax b/[:a::b] ; with a twist compose b/[(a:b)]; COMPOSE has to know about range notation compose b/[(a):(b)] ; COMPOSE doesn't know about range notation Thanks for the conversation on this! -- Gregg -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Hi Volker, VN Intersting: 'b/1:2/1:2 VN == b/1:02/1:02 VN a valid path. with time-values. VN now when i do a spreadsheed-dialect i could use rebol-syntax directly. VN with up to 60 columns :) I do kind of like the idea for a spreadsheet dialect. Have to think about how you could catch out-of-range errors. By extending the time! values to use minutes, you have a 3-D worksheet. :) -- Gregg -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Hi Volker, VN Gregg, cool . but how about parse? b: [1 2 3 4 5 6 7 8 9 10 11 12 13 14] VN == [1 2 3 4 5 6 7 8 9 10 11 12 13 14] parse b[ 4 skip copy v 2 skip] VN == false v VN == [5 6] That would work well for a single slice, but I'd still wrap it in a function to make the meaning clearer. For multiple slices, it would get ugly real fast I think. -- Gregg -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
before I start, I don't want you to know that I agree to most of what you say in theory, I'm just trying to see if there isn't a way to extend the base syntax in a way that code is shorter, and easier to read. Since we are in email, the tone gets perceived by the reader, not sent by the writter... I've had bad past experience in this kind of on-going discussions before (but not on this list :-) I love philosophy so, nothing here is personal... :-) - Original Message - From: Gregg Irwin It may be clear to programmers that are familiar with that notation, [ start : end ] Seemed clear to me, the first time I read it. a month. ago (I'm not a python expert, believe me... I generaly hate it) I even tought it used similar rebolish syntax... advanced features get used by advanced users... a lot of the code I see from the guru is hard to read for me, simply because it uses tricks I have not stumbled on yet... The words are all similar, but when looking at them, they seem to have no meaning. have you tried going through all the view code... there is much to learn, but darn some of it is almost impossible to grasp. another example is the series/:index notation I mean, really that wasn't obvious, although logical. Eventually, when a programmer gets to a point where he needs that notation, he jumps on the list and gets the answer... I've seen it already a few times this year... people are in-between and would understand the basic range notation, but would have to learn any extensions to it). nothing is clear in rebol, until you've programmed in it a few months. words not being variables, for example, is the basic thing in rebol which goes unnoticed until some weird thing happens in your code... its happened to all experienced reboler (unless they where already well versed in lisp speak, I guess). The n:m notation would conflict with time! values as well. My guess is that RT can make sure that if they found a path value with a block in it, they'd simply understand it as a range instead... isn't that what a dialect is? context specific code? General clarity aside, my gut reaction to the path/block/slice notation isn't positive. I don't think it buys us anything in the long run, and it could have a pretty serious impact on things if included as a base syntactical change it isnt really a change, its more of an addition, but I guess you mean that people creating dialects and expecting paths, would have to handle range notations too, then you are right, that it causes some mishaps. But then most of the code I get from this list already isn't supported in older versions of rebol... especially view v1.2.3 excerpt: func [ [...] ] cool func !! don't want to look picky but a: 1 b: 5 excerpt b [a to b] I know someone will say do this: excerpt b compose [(a) to (b)] but then, the idea behind the discussion starts loosing most of its sense. The idea I find, is that sometimes, lines of code get sooo long when a simple new notation could address them. cheers! -MAx -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Hi Maxim, Maxim Olivier-Adlhoch wrote: ... advanced features get used by advanced users... a lot of the code I see from the guru is hard to read for me, simply because it uses tricks I have not stumbled on yet... The words are all similar, but when looking at them, they seem to have no meaning. Yup, been there, done that, but didn't even get the T-Shirt ;-) have you tried going through all the view code... there is much to learn, but darn some of it is almost impossible to grasp. Right again. ... excerpt: func [ [...] ] cool func !! don't want to look picky but a: 1 b: 5 excerpt b [a to b] ... It's no problem to write the dialect to understand this (at least, once you understand how the 'layout dialect works (which, incidentally, I don't)). Any takers? Ingo -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
a[ 5 : 10 ] instead of copy/part skip a 5 skip a 10 ? how about extending path syntax? a/5:10 ? a/(5 + 7 + 29 + 3) is hard to read IMHO. the / is very hidden now. how about something spreadsheet-oriented? could even be a whole datatype. i would like to position inside a matrix, so having a: [ [1 2 3 4] [5 6 7 8] [9 A B C] ] b: skip-matrix a 2 2 ;fictional ! b/1/1 == 6 ! b/2/1 == A ! b/1:2/1:2 == [ [6 7] [A B] ] Half spreadsheet :) Intersting: 'b/1:2/1:2 == b/1:02/1:02 a valid path. with time-values. now when i do a spreadsheed-dialect i could use rebol-syntax directly. with up to 60 columns :) -Volker Am Sonntag, 19. Oktober 2003 21:29 schrieb Maxim Olivier-Adlhoch: before I start, I don't want you to know that I agree to most of what you say in theory, I'm just trying to see if there isn't a way to extend the base syntax in a way that code is shorter, and easier to read. Since we are in email, the tone gets perceived by the reader, not sent by the writter... I've had bad past experience in this kind of on-going discussions before (but not on this list :-) I love philosophy so, nothing here is personal... :-) - Original Message - From: Gregg Irwin It may be clear to programmers that are familiar with that notation, [ start : end ] Seemed clear to me, the first time I read it. a month. ago (I'm not a python expert, believe me... I generaly hate it) I even tought it used similar rebolish syntax... advanced features get used by advanced users... a lot of the code I see from the guru is hard to read for me, simply because it uses tricks I have not stumbled on yet... The words are all similar, but when looking at them, they seem to have no meaning. have you tried going through all the view code... there is much to learn, but darn some of it is almost impossible to grasp. another example is the series/:index notation I mean, really that wasn't obvious, although logical. Eventually, when a programmer gets to a point where he needs that notation, he jumps on the list and gets the answer... I've seen it already a few times this year... people are in-between and would understand the basic range notation, but would have to learn any extensions to it). nothing is clear in rebol, until you've programmed in it a few months. words not being variables, for example, is the basic thing in rebol which goes unnoticed until some weird thing happens in your code... its happened to all experienced reboler (unless they where already well versed in lisp speak, I guess). The n:m notation would conflict with time! values as well. My guess is that RT can make sure that if they found a path value with a block in it, they'd simply understand it as a range instead... isn't that what a dialect is? context specific code? General clarity aside, my gut reaction to the path/block/slice notation isn't positive. I don't think it buys us anything in the long run, and it could have a pretty serious impact on things if included as a base syntactical change it isnt really a change, its more of an addition, but I guess you mean that people creating dialects and expecting paths, would have to handle range notations too, then you are right, that it causes some mishaps. But then most of the code I get from this list already isn't supported in older versions of rebol... especially view v1.2.3 excerpt: func [ [...] ] cool func !! don't want to look picky but a: 1 b: 5 excerpt b [a to b] I know someone will say do this: excerpt b compose [(a) to (b)] but then, the idea behind the discussion starts loosing most of its sense. The idea I find, is that sometimes, lines of code get sooo long when a simple new notation could address them. cheers! -MAx -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
On 18-Oct-03, Maxim Olivier-Adlhoch wrote:
-Original Message- From: Carl Read
[mailto:[EMAIL PROTECTED] Sent: Friday, October 17, 2003 2:02
AM To: [EMAIL PROTECTED] Subject: [REBOL] Re: Cunning use of [],
() {} in R# and in future? Rebol versions?
On 17-Oct-03, Andrew Martin wrote:
Earlier I wrote:
X[2]
== b
It looks like I'm solving problems which not yet exist.
But it got me thinking anyway, so would this be useful...
blk: [a b c d e]
== [a b c d e]
blk/[1 4 5]
== [a d e]
now you're talking
it even looks rebolish... add python's list notation which is nice
(I must admit, and is missing altogether in rebol).
examples (with equivalent rebol line after):
series[5:10] - return a series starting at 5 ending at 10
copy/part at series 5 at series 10
series[5] - return element 5 series/5 (I'd rather keep series/5 and
add /[5] which returns a block with only the fifth element in it
series[:10] - return everything up to element 10
copy/part series at series 10
series[5:] - return everything starting a element 5
at series 5
you can even use negative indexes to reverse the direction...
so:
series[-5:-10]
reverse at series (length? series - 10) at series (length? series -
5)
the advantage of the python notation is that it is much more
unified. It is also often much shorter and more visual
I'm not saying scrap the current system (we needs its versatility
and oppeness), just adding some equivalent to the python method in
the way Carl just wrote it. We'd all benefit from shorter, often,
more redeable scripts.
I know we can write a function for it... but that adds a word in the
source which really isn't needed if its supported in the base
syntax. Only RT can do that.
the way carl just describes it, added with added range notation does
not break any current rebol syntax I can remember, yet it makes our
lives much simpler.
What do you all think?
I'm not sure how best to impliment it in a REBOL way, but it would be
nice. For selecting ranges within a series, perhaps parens could be
used something like this...
blk: [a b c d e f g]
== [a b c d e f g]
blk/[1 (3 5)]
== [a c d e]
blk/[(first 2) (5 last)]
== [a b e f g]
But, should it also work like this...
blk/[(first 2) (5 last)]/3
== e
?
--
Carl Read
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[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
That looks like a new range selection dialect. I can imagine a range-pick function perhaps: range-pick: func [series dialect][...] blk: [a b c d e f g] range-pick blk [1 (3 5)] ;== [a c d e] That would be similar to Andrew's picks function. Anton. I'm not sure how best to impliment it in a REBOL way, but it would be nice. For selecting ranges within a series, perhaps parens could be used something like this... blk: [a b c d e f g] == [a b c d e f g] blk/[1 (3 5)] == [a c d e] blk/[(first 2) (5 last)] == [a b e f g] But, should it also work like this... blk/[(first 2) (5 last)]/3 == e ? -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
That looks like a new range selection dialect. I can imagine a range-pick function perhaps: range-pick: func [series dialect][...] blk: [a b c d e f g] range-pick blk [1 (3 5)] ;== [a c d e] but now you can't leave the start and end infinite unless we do something like: blk/[ 1 (3 *)] I still prefer this type of syntax: blk/[1 3:5] it is clear, and uses the least typing each space defines a block to extract it also looks most like spreadsheets syntax when specifying ranges . we could even add the ~ or ! (not ) operator blk/[ 5: ~10 ] ; everything starting at 5 but not the tenth element. because the colon is already used, maybe we could simply use another character: -MAx -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Gregg, cool . but how about parse?
b: [1 2 3 4 5 6 7 8 9 10 11 12 13 14]
== [1 2 3 4 5 6 7 8 9 10 11 12 13 14]
parse b[ 4 skip copy v 2 skip]
== false
v
== [5 6]
-Volker
Am Samstag, 18. Oktober 2003 21:02 schrieb Gregg Irwin:
Max et al,
I agree that something more concise than raw REBOL (copy/part
at...) would be great, but the slice notation as used in Python and
Ruby isn't grabbing me--not for general use anyway.
MOA I still prefer this type of syntax:
MOA blk/[1 3:5]
MOA it is clear, and uses the least typing each space defines a block to
MOA extract it also looks most like spreadsheets syntax when specifying
MOA ranges.
...
MOA blk/[ 5: ~10 ] ; everything starting at 5 but not the tenth
element.
It may be clear to programmers that are familiar with that notation,
but I'm not sure it would be clear to normal people (spreadsheet
people are in-between and would understand the basic range notation,
but would have to learn any extensions to it).
The n:m notation would conflict with time! values as well.
General clarity aside, my gut reaction to the path/block/slice
notation isn't positive. I don't think it buys us anything in the long
run, and it could have a pretty serious impact on things if included
as a base syntactical change (particularly if it doesn't fit within
REBOL's current lexicon).
MOA because the colon is already used, maybe we could simply use another
MOA character:
If you simply use another character, then you: a) lose what I see as
the most positive aspect of it--that it's a known range notation for
some people, and b) fall into a what fits approach, rather than
designing for clear meaning and intent.
Now, since I disagree, it's only fair that I offer up a solution. :)
At the end of this message is a function called EXCERPT, that uses a
simple dialect. I originally called it CUT (as in the *nix utility
that does the same kind of thing), which also maps closely to the
slice concept in other languages. The problem I saw was that we're
not really cutting anything out, we're copying things out, so it isn't
really an accurate name (IIRC, Python and Ruby have different
semantics for slicing). COPY, SELECT, and PICK are already taken, as
is EXTRACT; though EXTRACT is a mezzanine that we could enhance, which
might be a better bet. EXCERPT implies the correct meaning to me, but
it isn't grabbing me as a great word so far. :)
Let me know what you think.
-- Gregg
; The dialect allows you to use commas in the block, but how they
; are interpreted is not how you might think. Coming after a number,
; they are a valid lexical form, but they denote a decimal! rather
; than being seen as a separator, which means you can't use them too
; flexibly.
excerpt: func [
{Returns the specified items and/or ranges from the series.}
series [series!]
offsets [block!] {Offsets of the items to extract; dialected.}
/only return sub-block ranges as blocks
/local
emit emit-range rules
from* to* index*; parse vars
result
][
emit: func [value] [
either only [append/only result value][append result value]
]
emit-range: func [start end] [
start: to integer! start
if number? end [end: to integer! end - start + 1]
emit either end = 'end [copy at series start][
copy/part at series start end
]
]
rules: [
some [
opt 'from set from* number! 'to set to* number! (
emit-range from* to*
)
| opt 'from set from* number! 'to 'end (emit-range from* 'end)
| 'to set to* number! (emit-range 1 to*)
| set index* number! (emit pick series index*)
| into rules
]
]
; Return a block. Easy enough for them to REJOIN if they want.
result: make block! length? series
parse offsets rules
result
]
b: [1 2 3 4 5 6 7 8 9 10 11 12 13 14]
excerpt b [1 3 5]
excerpt b [1 3 to 6 8]
excerpt/only b [1, 3 to 6, 8]
excerpt b [1 [5 to 7] 8]
excerpt/only b [1 (from 5 to 7) 8]
excerpt b [(to 2) [4 to 6] 8, 10, from 12 to end]
excerpt/only b [to 2, 4 to 6, 8, 10, (12 to end)]
; Can't use a comma after 'end
excerpt/only b [to 2 to 6 8 10 to end 12 to end]
excerpt/only b [to 2, to 6, 8 [10 to end] 12 to end]
excerpt/only trim {
REBOL is my favorite language
} [
to 5, 10 to 11, 13, 14, 15, 22 to end
]
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[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
On 17-Oct-03, Andrew Martin wrote: Earlier I wrote: X[2] == b It looks like I'm solving problems which not yet exist. But it got me thinking anyway, so would this be useful... blk: [a b c d e] == [a b c d e] blk/[1 4 5] == [a d e] ? -- Carl Read -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Carl Read wrote: Earlier I wrote: X[2] == b It looks like I'm solving problems which not yet exist. But it got me thinking anyway, so would this be useful... blk: [a b c d e] == [a b c d e] blk/[1 4 5] == [a d e] blk: [a b c d e] == [a b c d e] picks blk [1 4 5] == [a d e] :) Andrew J Martin Grail Jedi ICQ: 26227169 http://www.rebol.it/Valley/ http://valley.orcon.net.nz/ http://Valley.150m.com/ -- -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
On 17-Oct-03, A J Martin wrote: Carl Read wrote: Earlier I wrote: X[2] == b It looks like I'm solving problems which not yet exist. But it got me thinking anyway, so would this be useful... blk: [a b c d e] == [a b c d e] blk/[1 4 5] == [a d e] blk: [a b c d e] == [a b c d e] picks blk [1 4 5] == [a d e] :) ? picks No information on picks (word has no value) ? (Tried in View up to 1.2.10) -- Carl Read -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Carl Read wrote:
? picks
No information on picks (word has no value)
Hmmm, seems to work OK for me: :-)
source picks
picks: func [
[catch throw]
{Returns the values at the specified positions in the series.}
Series [series! pair! event! money! date! time! object! port! tuple!
any-function!]
Indexes [block!]
][
foreach Index Indexes collect/full/only [
if not number? Index [
throw make error! reduce ['script 'expect-arg 'Picks 'Indexes
mold [any number!]]
]
pick Series Index
]
]
Of course, you'll need the source for 'collect as well:
source collect
collect: func [
Collects the results of block evaluations.
Block [block!] The block to 'do.
/Only Inserts the result as a series.
/Full Don't ignore none! values.
/Initial Type [series! datatype!] Specifies the type of the result.
][
use [Break Result Results] [
Break: func [
Breaks out of the 'Collect.
/Return Forces the loop function to return a Value.
Value [any-type!]
] [
system/words/break/return either Return [
Value
] [
Results
]
]
Results: any [
all [
datatype? Type
make Type 0
]
Type
copy []
]
compose/deep [
if not any [
unset? set/any 'Result do [(bind Block 'Break)]
(pick [[none? :Result] []] not Full)
] [
(pick [insert insert/only] not Only) tail Results :Result
Results
]
Results
]
]
]
Enjoy!
Andrew J Martin
Grail Jedi
ICQ: 26227169
http://www.rebol.it/Valley/
http://valley.orcon.net.nz/
http://Valley.150m.com/
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[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
-Original Message-
From: Carl Read [mailto:[EMAIL PROTECTED]
Sent: Friday, October 17, 2003 2:02 AM
To: [EMAIL PROTECTED]
Subject: [REBOL] Re: Cunning use of [], () {} in R# and in future?
Rebol versions?
On 17-Oct-03, Andrew Martin wrote:
Earlier I wrote:
X[2]
== b
It looks like I'm solving problems which not yet exist.
But it got me thinking anyway, so would this be useful...
blk: [a b c d e]
== [a b c d e]
blk/[1 4 5]
== [a d e]
now you're talking
it even looks rebolish... add python's list notation which is nice (I must admit, and
is missing altogether in rebol).
examples (with equivalent rebol line after):
series[5:10] - return a series starting at 5 ending at 10
copy/part at series 5 at series 10
series[5]- return element 5
series/5 (I'd rather keep series/5 and add /[5] which returns a block with only the
fifth element in it
series[:10] - return everything up to element 10
copy/part series at series 10
series[5:] - return everything starting a element 5
at series 5
you can even use negative indexes to reverse the direction...
so:
series[-5:-10]
reverse at series (length? series - 10) at series (length? series - 5)
the advantage of the python notation is that it is much more unified. It is also often
much shorter and more visual
I'm not saying scrap the current system (we needs its versatility and oppeness), just
adding some equivalent to the python method in the way Carl just wrote it. We'd all
benefit from shorter, often, more redeable scripts.
I know we can write a function for it... but that adds a word in the source which
really isn't needed if its supported in the base syntax. Only RT can do that.
the way carl just describes it, added with added range notation does not break any
current rebol syntax I can remember, yet it makes our lives much simpler.
What do you all think?
-MAx
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[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Hi all - This thread reminds me of some of the very nice MATLAB notation for referencing matrix or array elements: A(1:10) - elements 1 thru 10 A(:,5:10) - all rows, only columns 5 thru 10 A(5:10,:) - all columns, only rows 5 thru 10 A(:) - all elements A'- all elements transposed (cols switched with rows) dimension r x c becomes c x r It might be nice to accommodate the two dimensional idea as an enhancement; n-dimensional referencing might be nice too... A REBOL shorthand for block or series referencing in this flavor might be very helpful -- at least I think it would. On the other hand, I've got a long way to go before I appreciate the subtleties of REBOL ... Mike SNIP now you're talking it even looks rebolish... add python's list notation which is nice (I must admit, and is missing altogether in rebol). examples (with equivalent rebol line after): series[5:10] - return a series starting at 5 ending at 10 copy/part at series 5 at series 10 series[5]- return element 5 series/5 (I'd rather keep series/5 and add /[5] which returns a block with only the fifth element in it series[:10] - return everything up to element 10 copy/part series at series 10 series[5:] - return everything starting a element 5 at series 5 you can even use negative indexes to reverse the direction... so: series[-5:-10] reverse at series (length? series - 10) at series (length? series - 5) the advantage of the python notation is that it is much more unified. It is also often much shorter and more visual I'm not saying scrap the current system (we needs its versatility and oppeness), just adding some equivalent to the python method in the way Carl just wrote it. We'd all benefit from shorter, often, more redeable scripts. I know we can write a function for it... but that adds a word in the source which really isn't needed if its supported in the base syntax. Only RT can do that. the way carl just describes it, added with added range notation does not break any current rebol syntax I can remember, yet it makes our lives much simpler. What do you all think? -MAx -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject. -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Andrew Martin wrote:
It occurred to me as I was writing Rebol code, that it's possible to
re-use these characters [], () {}, in useful ways. I've
noticed that
when I'm writing block!, paren! string values, I leave white space
before and after the [], () {} characters. It would be
nice to have:
X: [a b c]
== [a b c]
X[2]
== b
more liquely [EMAIL PROTECTED], X#2, X2, X\2, X.2, X|2, X,2
one would equate to
at X 2
[b c]
another to
at head X 2
this breaks no current rules (it might collide with mail datatype though?) and is a
logical complement for the X/2 which we all use. If a specific datatype does not
usually return a block (like a tuple), then it would have to do so.
print [my 0.02 (locale/currency)]
-MAx
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[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Hum. If this magic-char-thread is serious, could i borrow someone my
perl-interpreter? ;)
-Volker
Am Donnerstag, 16. Oktober 2003 15:06 schrieb Maxim Olivier-Adlhoch:
Andrew Martin wrote:
It occurred to me as I was writing Rebol code, that it's possible to
re-use these characters [], () {}, in useful ways. I've
noticed that
when I'm writing block!, paren! string values, I leave white space
before and after the [], () {} characters. It would be
nice to have:
X: [a b c]
== [a b c]
X[2]
== b
more liquely [EMAIL PROTECTED], X#2, X2, X\2, X.2, X|2, X,2
one would equate to
at X 2
[b c]
another to
at head X 2
this breaks no current rules (it might collide with mail datatype though?)
and is a logical complement for the X/2 which we all use. If a specific
datatype does not usually return a block (like a tuple), then it would have
to do so.
print [my 0.02 (locale/currency)]
-MAx
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[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Volker wrote: Hum. If this magic-char-thread is serious, could I borrow someone my perl-interpreter? ;) With Rebol, my words mean what I want them to mean. :) :-/ But if I want to be understood and want to understand others, it's best that we all agree on what Rebol or R# words mean to all of us! :) Andrew J Martin Attendance Officer, Grail Jedi, Knight of Lucidity destroyer of gibberish! Colenso High School Arnold Street, Napier. Tel: 64-6-8310180 ext 826 Fax: 64-6-8336759 http://colenso.net/scripts/Wiki.r?AJM http://www.colenso.school.nz/ DISCLAIMER: Colenso High School and its Board of Trustees is not responsible (or legally liable) for materials distributed to or acquired from user e-mail accounts. You can report any misuse of an e-mail account to our ICT Manager and the complaint will be investigated. (Misuse can come in many forms, but can be viewed as any material sent/received that indicate or suggest pornography, unethical or illegal solicitation, racism, sexism, inappropriate language and/or other issues described in our Acceptable Use Policy.) All outgoing messages are certified virus-free by McAfee GroupShield Exchange 5.10.285.0 Phone: +64 6 843 5095 or Fax: +64 6 833 6759 or E-mail: [EMAIL PROTECTED] -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Hi Andrew,
AM It occurred to me as I was writing Rebol code, that it's possible to
AM re-use these characters [], () {}, in useful ways. I've noticed that
AM when I'm writing block!, paren! string values, I leave white space
AM before and after the [], () {} characters. It would be nice to have:
X: [a b c]
AM == [a b c]
X[2]
AM == b
AM In other words, by running the block hard against the word, it's like:
AM pick X 2
I'd stick with standard notations. I like the idea that blocks are
blocks and not used as another notation. As others have pointed out,
we have path notation (which is even more concise than the C/C# notation
for accessing array elements).
-- Gregg
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[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Earlier I wrote: X[2] == b It looks like I'm solving problems which not yet exist. Andrew J Martin Attendance Officer Grail Jedi, fighting with laser swords... Colenso High School Arnold Street, Napier. Tel: 64-6-8310180 ext 826 Fax: 64-6-8336759 http://colenso.net/scripts/Wiki.r?AJM http://www.colenso.school.nz/ DISCLAIMER: Colenso High School and its Board of Trustees is not responsible (or legally liable) for materials distributed to or acquired from user e-mail accounts. You can report any misuse of an e-mail account to our ICT Manager and the complaint will be investigated. (Misuse can come in many forms, but can be viewed as any material sent/received that indicate or suggest pornography, unethical or illegal solicitation, racism, sexism, inappropriate language and/or other issues described in our Acceptable Use Policy.) All outgoing messages are certified virus-free by McAfee GroupShield Exchange 5.10.285.0 Phone: +64 6 843 5095 or Fax: +64 6 833 6759 or E-mail: [EMAIL PROTECTED] -- To unsubscribe from this list, just send an email to [EMAIL PROTECTED] with unsubscribe as the subject.
[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Andrew,
That would break some existing Rebol scripts. Right now, someone might
have some Rebol code written like:
x: true
either X[2][3]
This would break with your implementation.
Why not use X/2 ? It's shorter anyway.
Bohdan Bo Lechnowsky
Lechnowsky Technical Consulting
At 05:05 PM 10/16/03 +1300, you wrote:
It occurred to me as I was writing Rebol code, that it's possible to
re-use these characters [], () {}, in useful ways. I've noticed that
when I'm writing block!, paren! string values, I leave white space
before and after the [], () {} characters. It would be nice to have:
X: [a b c]
== [a b c]
X[2]
== b
In other words, by running the block hard against the word, it's like:
pick X 2
I don't know what use () and {} could have, though. What's your
thoughts?
Andrew J Martin
Attendance Officer
Grail Jedi who is tapping on the dungeon wall with Rebol...
Colenso High School
Arnold Street, Napier.
Tel: 64-6-8310180 ext 826
Fax: 64-6-8336759
http://colenso.net/scripts/Wiki.r?AJM
http://www.colenso.school.nz/
DISCLAIMER: Colenso High School and its Board of Trustees is not
responsible (or legally
liable) for materials distributed to or acquired from user e-mail
accounts. You can report any
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investigated.
(Misuse can come in many forms, but can be viewed as any material
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[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
X: [a b c]
== [a b c]
X[2]
== b
In other words, by running the block hard against the word, it's like:
pick X 2
Why not simply use path (x/2 in the example above) notation, it saves a
character at least. ;)
As for finding other uses for [], () {}, if it makes sense in a
certain context then great, but I suspect it could lead to subtle and hard
to find errors (especially of the mismatched number of opening / closing
xxx type).
Regards,
Ashley
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[REBOL] Re: Cunning use of [], () {} in R# and in future? Rebol versions?
Hi Andrew.
You wrote:
I've noticed that when I'm writing block!, paren!
string values, I leave white space before and after
the [], () {} characters.
After puzzling over your intro briefly, it appears to me that you see
the additional space as being significant in distinguishing between your
two examples:
(1) With space
X: [a b c]
== [a b c]
and (2) without space
X[2]
== b
Notice, however, that the colon is also missing in example 2. I.e., even
if you were not to supply the extra space in example 1, i.e.
X:[a b c] ;- example 3
you would still have the significant distinction to example 2 in that
in example 3 you again have the colon separating the X from the block ,
whereas in example (i.e. X[2]) there is no such colon.
Andrew Martin wrote:
It occurred to me as I was writing Rebol code, that it's possible to
re-use these characters [], () {}, in useful ways. I've noticed that
when I'm writing block!, paren! string values, I leave white space
before and after the [], () {} characters. It would be nice to have:
X: [a b c]
== [a b c]
X[2]
== b
In other words, by running the block hard against the word, it's like:
pick X 2
I don't know what use () and {} could have, though. What's your
thoughts?
Andrew J Martin
Attendance Officer
Grail Jedi who is tapping on the dungeon wall with Rebol...
Colenso High School
Arnold Street, Napier.
Tel: 64-6-8310180 ext 826
Fax: 64-6-8336759
http://colenso.net/scripts/Wiki.r?AJM
http://www.colenso.school.nz/
DISCLAIMER: Colenso High School and its Board of Trustees is not responsible (or
legally
liable) for materials distributed to or acquired from user e-mail accounts. You can
report any
misuse of an e-mail account to our ICT Manager and the complaint will be
investigated.
(Misuse can come in many forms, but can be viewed as any material sent/received that
indicate or suggest pornography, unethical or illegal solicitation, racism, sexism,
inappropriate
language and/or other issues described in our Acceptable Use Policy.)
All outgoing messages are certified virus-free by McAfee GroupShield Exchange
5.10.285.0
Phone: +64 6 843 5095 or Fax: +64 6 833 6759 or E-mail: [EMAIL PROTECTED]
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