[REBOL] shifting characters in rejoin Re:(2)
Hi, Chris, Actually, it depends on which Lisp... According to the LISP 1.5 Programmer's Manual, page 60, Table Building and Table Reference Functions pair[x;y] : SUBR The function pair has as value the list of pairs of corresponding elements of the lists x and y. The arguments x and y must be lists of the same number of elements. ... Of course, that manual has serious grey hair! The preface is dated 17 Aug 1962 (although my copy is from the 6th printing, April 1972). Actually, if I were going to go by that ancient manual, I'd have to call the apply-function-across-list operator maplist , because the name map was given to a side-effects-only version that always returned nil . (OK, I couldn't help but throw in a little archaeology ;-) Actually, I had a more pragmatic reason for ducking the multiple- lists-as-arguments issue -- REBOL syntax! [EMAIL PROTECTED] wrote: > > In Lisp this function is still MAP. MAP takes any number of > sequences and the function takes a number of arguments equal > to the number of sequences: > > (map 'vector #'max '(4 7 16) '(9 5 15)) > => '(9 7 16) > > Perhaps the REBOL map implementation could do the same. > As Lisp explicitly delimits each function application, it's easy to tell how many lists are being supplied as arguments to map (as in your example). The only reliable way I know in REBOL to pass a varying number of arguments is to put them in a block... map [ [...] [...] [...] ] some-function ...but I was hesitant to do that for a few reasons. First of all, I'd like to be able to do things like these: >> accum: func [a [any-type!] b [any-block!] f [any-function!]][ [foreach c b [a: f a c] [a [] >> map [[1 2 1] [2 3 3] [3 6 5]] func [b [block!]] [ [append b (accum 0 b :+) / (length? b) [] == [[1 2 1 1.33] [2 3 3 2.67] [3 6 5 4.67]] ...or... >> namer: make object! [ [curr: #"a" [next: func [/local r] [ [r: curr curr: curr + 1 r [] [] >> map [[1 2 1] [2 3 3] [3 6 5]] func [b [block!]] [ [head insert head copy b to-string namer/next [] == [["a" 1 2 1] ["b" 2 3 3] ["c" 3 6 5]] where the function is to be applied to each block that is an element of the (single!) argument block. Second, I'd thought about (although I didn't include it in my earlier posts) adding a /deep refinement by analogy with a similar one for copy (etc.) that would recur(se) on any nested blocks. Finally, I'd considered handling the structure-traversing issues separately from the data-manipulation issues, by defining (this version is VERY quick and dirty): >> transpose: function [b [block!]] [w i s r] [ [r: make block! w: accum length? b/1 map b :length? :min [repeat i w [ [s: make block! length? b [foreach c b [append/only s c/:i] [append/only r s [] [r [] >> transpose [[1 2 3 4 5] ["a" "b" "c" "d" "e"]] == [[1 "a"] [2 "b"] [3 "c"] [4 "d"] [5 "e"]] >> transpose [[1 2 3] [14 15 16] [27 28 29]] == [[1 14 27] [2 15 28] [3 16 29]] >> my-scores: [4 7 16 2 12 13] == [4 7 16 2 12 13] >> your-scores: [9 5 15 1 15 15] == [9 5 15 1 15 15] >> games: transpose reduce [my-scores your-scores] == [[4 9] [7 5] [16 15] [2 1] [12 15] [13 15]] ...and so forth. Critiques/comments/debugging welcome! -jn-
[REBOL] shifting characters in rejoin Re:
> The next one (I can't recall if there's a common name for it) can be > used for statistics and other fun things: In Lisp this function is still MAP. MAP takes any number of sequences and the function takes a number of arguments equal to the number of sequences: (map 'vector #'max '(4 7 16) '(9 5 15)) => '(9 7 16) Perhaps the REBOL map implementation could do the same. Chris. -- http://www.double.co.nz/cl http://www.double.co.nz/dylan
[REBOL] shifting characters in rejoin Re:(2)
Thanks, guys, for the answer. I didn't think about there being a datatyping problem, but that makes perfect sense now. >A tag! is meant to represent only one tag. If you want to have more than one >tag in an HTML element, you need to make a string. So it's very easy to >correct your function. Replace the line quoted above with: > > markup-string: rejoin ["" open-tag data/name close-tag]
[REBOL] shifting characters in rejoin Re:
Hi Ryan,
Andrew Martin already answered you, but maybe this provides a little
different perspective ...
The results look strange because the < and > aren't part of the tag!
data, they just delimit it.
>> length?
== 3
When you do
markup-string: rejoin [open-tag data/name close-tag]
the first item in REJOIN's block argument is a tag, so the result is
a tag. But before close-tag is appended, it is formed to a string,
which causes the delimiting < > to actually become characters of data.
A tag! is meant to represent only one tag. If you want to have more than one
tag in an HTML element, you need to make a string. So it's very easy to
correct your function. Replace the line quoted above with:
markup-string: rejoin ["" open-tag data/name close-tag]
Eric
>I have created a function which returns something strange when I use
>rejoin.
>
>The function is called build-html.r which builds a markup statement.
>Here is the console result. Notice the closing bracket for the opening
>tag is strangely moved to the end of the rejoined string:
>
>>> do %build-html.r
>Script: "Untitled" (none)
>== >
>>>
>
>Your input would be helpful. -Ryan
>
>Here is the script:
>
>REBOL []
>
>author: make object! [
>name: "Ryan C. Christiansen"
>email-address: [EMAIL PROTECTED]
>stylesheet-info: make object! [
>tag-style: "font"
> class-name: "author"
>]
>]
>
>build-html: func [
>{Build an HTML page element including the data to be displayed
> and the markup language surrounding the data.}
>data [object!] "the data to be marked up"
>][
>open-tag: build-tag [(data/stylesheet-info/tag-style) class
> (data/stylesheet-info/class-name)]
>
>close-tag: rejoin [{}]
>
>markup-string: rejoin [open-tag data/name close-tag]
>
>markup-string
>
>]
>
>build-html author
[REBOL] shifting characters in rejoin Re:(2)
> You've run into the interesting way that 'join works on tag!. > > >> rejoin [ "class=" "Ryan C. Christiansen" ] > == > > > Basically you have to convert the tags to strings to work as you'd expect, as 'join on a tag! will put the stuff in the block inside the tag. I forgot to mention that the end result of 'join and 'rejoin is to make the result the same datatype! as the first datatype in the block for 'rejoin or first argument of 'join. >> type? rejoin [ "class=" "Ryan C. Christiansen" ] == tag! What's the type! of this one expression? ;-) Andrew Martin ICQ: 26227169 http://members.nbci.com/AndrewMartin/ http://members.xoom.com/AndrewMartin/ -><-
[REBOL] shifting characters in rejoin Re:
> I have created a function which returns something strange when I use
rejoin.
>
> The function is called build-html.r which builds a markup statement. Here
is the console result. Notice the closing bracket for the opening tag is
strangely moved to the end of the rejoined string:
> >> do %build-html.r
> Script: "Untitled" (none)
> == >
You've run into the interesting way that 'join works on tag!.
>> rejoin [ "class=" "Ryan C. Christiansen" ]
== >
Basically you have to convert the tags to strings to work as you'd expect,
as 'join on a tag! will put the stuff in the block inside the tag.
Something like this from my HTML! component, soon to be released on RebMail
list, and my Web Dialect list:
A: func [File [file! url!] Link [string!] /Top] [
rejoin ["" join [{ href="} Encode File {"} either Top [{
TARGET="_top"}] [""]] Link ]
]
Which from script like this:
H1 A URL/Absolute Spectrum-Studios Name Spectrum-Studios
generates HTML like this:
http://members.nbci.com/SpectrumStudios/Spectrum%20Studios.html">Spect
rum Studios
The above line is broken by the email client I'm using.
Note that 'Spectrum-Studios is a object like:
Spectrum-Studios: Make-Page "Spectrum Studios" %"Spectrum Studios.html" [
Title Name Spectrum-Studios
Body
I hope that helps!
Andrew Martin
ICQ: 26227169
http://members.nbci.com/AndrewMartin/
http://members.xoom.com/AndrewMartin/
-><-
[REBOL] shifting characters in rejoin
I have created a function which returns something strange when I use
rejoin.
The function is called build-html.r which builds a markup statement.
Here is the console result. Notice the closing bracket for the opening
tag is strangely moved to the end of the rejoined string:
>> do %build-html.r
Script: "Untitled" (none)
== >
>>
Your input would be helpful. -Ryan
Here is the script:
REBOL []
author: make object! [
name: "Ryan C. Christiansen"
email-address: [EMAIL PROTECTED]
stylesheet-info: make object! [
tag-style: "font"
class-name: "author"
]
]
build-html: func [
"Build an HTML page element including the data to be displayed
and the markup language surrounding the data."
data [object!] "the data to be marked up"
][
open-tag: build-tag [(data/stylesheet-info/tag-style) class
(data/stylesheet-info/class-name)]
close-tag: rejoin [{}]
markup-string: rejoin [open-tag data/name close-tag]
markup-string
]
build-html author
