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-rw-r--r--NEWS1
-rw-r--r--doc/user/syntax.skb19
-rw-r--r--po/POTFILES.in1
-rw-r--r--src/guile/Makefile.am3
-rwxr-xr-xsrc/guile/skribilo/reader/rss-2.scm349
5 files changed, 372 insertions, 1 deletions
diff --git a/NEWS b/NEWS
index 5db8603..5ae4a91 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@ Copyright (C) 2005, 2006, 2007, 2008 Ludovic Courtès <ludo@gnu.org>
** `skribilo' now displays a call stack trace upon error when possible
** New `--custom' compiler option
** Using `(image :url ...)' with `lout' yields a warning, not an error
+** New `rss-2' input syntax, for RSS 2.0 feeds
* New in Skribilo 0.9.1
diff --git a/doc/user/syntax.skb b/doc/user/syntax.skb
index cdcdf9c..ba2b800 100644
--- a/doc/user/syntax.skb
+++ b/doc/user/syntax.skb
@@ -210,6 +210,25 @@ documents that can be output in variety of formats (see ,(numref :text
markup-less document format, there are many things that cannot be done
using it, most notably tables, bibliographies, and cross-references.]))
+ (section :title [The RSS 2.0 Syntax]
+ :ident "rss2-syntax"
+
+ (p [RSS 2.0 (aka. ,(ref :url "http://en.wikipedia.org/wiki/RSS" :text
+(emph [Really Simple Syndication]))) is supported as an input syntax.
+To use it, just pass ,(tt [--reader=rss-2]) to the compiler. This
+makes it possible to generate Skribilo documents from RSS 2.0 feeds,
+which can be useful or at least funny. Consider the following example:]
+
+ (disp :verb #t [
+$ wget http://planet.gnu.org/rss20.xml
+$ skribilo -R rss-2 -t lout -c column-number=2 < rss20.xml \\
+ | lout | ps2pdf - > gnu-planet.pdf
+])
+
+[It produces a two-column PDF file with the contents of the RSS feed of
+GNU Planet, where each item of the feed is mapped to a Skribilo
+``chapter''.]))
+
(section :title [Documents in Scheme Programs]
:ident "scheme-syntax"
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 3132e9a..7754e67 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -13,3 +13,4 @@ src/guile/skribilo/source.scm
src/guile/skribilo/sui.scm
src/guile/skribilo/verify.scm
src/guile/skribilo/engine/lout.scm
+src/guile/skribilo/reader/rss-2.scm
diff --git a/src/guile/Makefile.am b/src/guile/Makefile.am
index 28266e0..aa90fbe 100644
--- a/src/guile/Makefile.am
+++ b/src/guile/Makefile.am
@@ -47,7 +47,8 @@ nobase_dist_module_DATA += \
$(readers) $(engines) $(packages)
readers = \
- skribilo/reader/skribe.scm skribilo/reader/outline.scm
+ skribilo/reader/skribe.scm skribilo/reader/outline.scm \
+ skribilo/reader/rss-2.scm
engines = \
skribilo/engine/base.scm skribilo/engine/context.scm \
diff --git a/src/guile/skribilo/reader/rss-2.scm b/src/guile/skribilo/reader/rss-2.scm
new file mode 100755
index 0000000..f71a967
--- /dev/null
+++ b/src/guile/skribilo/reader/rss-2.scm
@@ -0,0 +1,349 @@
+;;; rss-2.scm -- A reader for RSS 2.0 files.
+;;;
+;;; Copyright 2008 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;;
+;;; This program is free software; you can redistribute it and/or modify
+;;; it under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 2 of the License, or
+;;; (at your option) any later version.
+;;;
+;;; This program is distributed in the hope that it will be useful,
+;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with this program; if not, write to the Free Software
+;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+;;; USA.
+
+(define-module (skribilo reader rss-2)
+
+ ;; We depend on `guile-library' (available in Debian).
+ :use-module (sxml simple)
+ :use-module (htmlprag)
+
+ :use-module (ice-9 match)
+ :use-module (srfi srfi-1)
+ :use-module (srfi srfi-13)
+ :use-module (srfi srfi-14)
+ :use-module (srfi srfi-19)
+ :use-module (srfi srfi-34)
+ :use-module (srfi srfi-35)
+
+ :use-module (skribilo reader)
+ :use-module (skribilo utils syntax)
+
+ :export (reader-specification))
+
+(fluid-set! current-reader %skribilo-module-reader)
+
+;;; Author: Ludovic Courtès
+;;;
+;;; Commentary:
+;;;
+;;; A reader for RSS 2.0 feeds that turn a feed into a Skribilo document.
+;;; See http://en.wikipedia.org/wiki/RSS for more information on RSS.
+;;;
+;;; Code:
+
+
+
+;;;
+;;; RSS 2.0 utilities.
+;;;
+
+(define (rss-channels feed)
+ ;; Return the list of RSS 2.0 channels contained in FEED, an SXML tree.
+ (match feed
+ (('*TOP* ('*PI* _ ...)
+ ('rss ('@ ('version "2.0"))
+ body ...))
+ (filter (lambda (tag)
+ (and (pair? tag)
+ (eq? (car tag) 'channel)))
+ body))
+ (_
+ (raise (condition
+ (&message
+ (message (_ "input is not a valid RSS 2.0 feed"))))))))
+
+(define (channel-items channel)
+ ;; Return the list of items of CHANNEL, an SXML tree.
+ (filter (lambda (tag)
+ (and (pair? tag)
+ (eq? (car tag) 'item)))
+ channel))
+
+(define (channel-title channel)
+ ;; Return the title of CHANNEL, the SXML tree of an RSS 2.0 channel.
+ (let ((title (find-tag channel 'title)))
+ (and (pair? title)
+ (cadr title))))
+
+
+;;;
+;;; Skribilo output.
+;;;
+
+(define (warn* fmt . args)
+ (apply format
+ (current-error-port)
+ (string-append "rss-2: " fmt "~%")
+ args))
+
+(define (html-string->parse-tree str)
+ ;; Remove the leading `*TOP*'.
+ (cdr (html->shtml str)))
+
+(define (generic-tag->skribe tag)
+ (let loop ((tag tag))
+ (match tag
+ ((? string? tag)
+ tag)
+
+ (()
+ ''())
+
+ ((and ((? string?) ...) strings)
+ (string-concatenate strings))
+
+ (('p body ...)
+ (let ((body (map loop body)))
+ (if (or (null? body)
+ (not (symbol? (car body))))
+ `(p ,@body)
+ `(p ,body))))
+
+ (('font ('@ params ...) body ...)
+ (let ((color (assq 'color params))
+ (body (map loop body)))
+ (if (pair? color)
+ `(color :fg ,(cadr color) ,@body)
+ `(list ,@body))))
+
+ (('img ('@ params ...) body ...)
+ (let ((src (assq 'src params))
+ (alt (assq 'alt params)))
+ (if (pair? src)
+ `(image :url ,(cadr src) ,(and (pair? alt) (cadr alt)))
+ `(list ,@body))))
+
+ (('a ('@ ('href ref) _ ...) text ...)
+ (if (null? text)
+ `(ref :url ,ref)
+ `(ref :url ,ref :text ,@(map loop text))))
+
+ (((or 'em 'strong) text ...)
+ `(emph ,@(map loop text)))
+
+ (((or 'i 'sl) text ...)
+ `(it ,@text))
+
+ (('b text ...)
+ `(bold ,@(map loop text)))
+
+ (((and (or 'code 'tt 'q) simple-tag) text ...)
+ `(,simple-tag ,@(map loop text)))
+
+ (('textarea ('@ params ...) body ...)
+ `(pre ,@(map loop body)))
+
+ (('pre body ...)
+ `(pre ,@(map loop body)))
+
+ (('acronym ('@ _ ...) body ...)
+ ;; XXX: We don't (yet?) have an `acronym' markup.
+ `(list ,@body))
+
+ (('input ('@ params ...) body ...)
+ (let ((value (assq 'value params)))
+ (and (pair? value)
+ `(pre (code ,(cadr value))))))
+
+ ((or ('blockquote ('@ _ ...) body ...)
+ ('blockquote body ...))
+ `(blockquote ,@(map loop body)))
+
+ (((or 'br 'hr) _ ...)
+ `(linebreak))
+
+ (((or 'ul 'ol) (and (or ('li _ ...) _) items) ...)
+ (let ((items (filter pair? items)))
+ (cons (if (eq? (car tag) 'ul) 'itemize 'enumerate)
+ (map (lambda (item)
+ (let ((body (map loop (cdr item))))
+ (cons 'item body)))
+ items))))
+
+ ((or ('dl ('@ _ ...) body ...)
+ ('dl body ...))
+ (let ((items (filter pair? body)))
+ `(itemize
+ ,@(let liip ((items items)
+ (keys '())
+ (result '()))
+ (if (null? items)
+ (begin
+ (format (current-error-port) "ITEMS = ~s~%" result)
+ (reverse result))
+ (match (car items)
+ ((or ('dt ('@ _ ...) text ...)
+ ('dt text ...))
+ (liip (cdr items)
+ (cons text keys)
+ result))
+ ((or ('dd ('@ _ ...) text ...)
+ ('dd text ...))
+ (liip (cdr items)
+ '()
+ (cons `(item :key (list ,@(map loop (reverse keys)))
+ ,@(map loop text))
+ result)))
+ (_
+ (liip (cdr items) keys result))))))))
+
+ ((or ('table ('@ _ ...) body ...)
+ ('table body ...))
+ `(table ,@(filter-map (lambda (x)
+ (and (pair? x) (loop x)))
+ body)))
+
+ ((or ((and (or 'tr 'th 'td 'tc) tag) ('@ _ ...) body ...)
+ ((and (or 'tr 'th 'td 'tc) tag) body ...))
+ `(,tag ,@(map loop body)))
+
+ (('*ENTITY* "additional" "nbsp")
+ `(~))
+
+ (('*ENTITY* "additional-char" (? string? char))
+ (let ((char (string->number char)))
+ (and (< char 256)
+ (integer->char char))))
+
+ ((and (((not (? symbol?)) _ ...) ...) lst)
+ ;; Flatten non-markup lists.
+ (loop (concatenate lst)))
+
+ ((or ((or 'span 'div) ('@ _ ...) body ...)
+ ((or 'span 'div) body ...))
+ (let ((body (map loop body)))
+ (if (or (null? body)
+ (not (symbol? (car body))))
+ `(list ,@body)
+ `(list ,body))))
+
+ (('*PI* 'xml (? string? body))
+ ;; Seen on MS-generated code: an <xml> tag in the middle of the
+ ;; <description>!
+ `(list ,@(loop (html-string->parse-tree body))))
+
+ (((? symbol? unsupported-tag) rest ...)
+ (warn* (_ "tag `~s' ignored") tag)
+ #f)
+
+ ((lst ...)
+ (map loop lst))
+
+ (_
+ (warn* (_ "skipping tag `~a'~%") tag)
+ #f))))
+
+(define (english-date->date str)
+ (let ((locale (setlocale LC_ALL)))
+ (dynamic-wind
+ (lambda ()
+ (setlocale LC_ALL "C"))
+ (lambda ()
+ ;; The hack below allows us to process some of the feeds that use a
+ ;; non-conforming time zone field in `pubDate' (e.g., feeds from
+ ;; `livejournal.com').
+ (let ((str (if (string-suffix? "GMT" str)
+ (string-append (substring str 0
+ (- (string-length str) 3))
+ "+0000")
+ str)))
+ (string->date str "~a, ~d ~b ~Y ~H:~M:~S ~z")))
+ (lambda ()
+ (setlocale LC_ALL locale)))))
+
+(define (find-tag sxml tag)
+ ;; Return the first sub-tree of SXML with tag TAG.
+ (find (lambda (x)
+ (and (pair? x)
+ (eq? (car x) tag)))
+ sxml))
+
+(define (item->section item markup)
+ ;; Turn ITEM, the SXML tree of an RSS item, into a section of type MARKUP
+ ;; (e.g., `chapter' or `section').
+ (let ((title (find-tag item 'title))
+ (date (find-tag item 'pubDate))
+ (desc (find-tag item 'description)))
+ `(,markup :title ',(cadr title)
+
+ (p (bold ,(string-trim-both
+ (date->string (english-date->date (cadr date))
+ "~e ~B ~Y")))
+ ". ")
+
+ ,@(generic-tag->skribe
+ (html-string->parse-tree (cadr desc))))))
+
+(define (feed->document feed)
+ ;; Return a Skribilo `(document ...)' S-exp from FEED, the SXML tree of an
+ ;; RSS 2.0 feed.
+ (let ((channels (rss-channels feed)))
+ (if (null? channels)
+ (raise (condition
+ (&message
+ (message (_ "no RSS 2.0 channels found in feed")))))
+ (let ((title (channel-title (car channels)))
+ (single? (null? (cdr channels))))
+ ;; When there's only one channel, promote items as chapters.
+ `(document :title ,title
+ ,@(if single?
+ (map (lambda (item)
+ (item->section item 'chapter))
+ (channel-items (car channels)))
+ (map (lambda (channel)
+ `(chapter :title ,(channel-title channel)
+ ,@(map (lambda (item)
+ (item->section item 'section))
+ (channel-items channel))))
+ channels)))))))
+
+
+;;;
+;;; The reader.
+;;;
+
+(define (skip-white-space port)
+ ;; Skip white space from PORT. Return the last character read or the EOF
+ ;; object.
+ (let loop ((c (peek-char port)))
+ (if (eof-object? c)
+ c
+ (if (char-set-contains? char-set:whitespace c)
+ (begin
+ (read-char port)
+ (loop (peek-char port)))
+ c))))
+
+(define (make-rss-reader)
+ (lambda (port)
+ ;; XXX: Hack to avoid "Unexpected EOF" errors in `xml->sxml'.
+ (let ((c (skip-white-space port)))
+ (if (eof-object? c)
+ c
+ (feed->document (xml->sxml port))))))
+
+
+;;;
+;;; The reader specification.
+;;;
+
+(define-reader rss-2 "0.1" make-rss-reader)
+
+;;; rss-2.scm ends here
generated by cgit v1.2.3 (git 2.44.0) at 2024-06-01 12:01:38 +0000