+++ /dev/null
----
-postid: 086
-title: An XML parser for Common Lisp programs
-date: February 18, 2019
-author: Lucian Mogoșanu
-tags: tech, tmsr
----
-
-This post is part of a [series][tmsr-schedule-i] of published
-[artifacts][intellectual-ownership] that (will) represent components for
-The Republic's RSS bot, [Feedbot][feedbot]. The idea behind this series
-is to grow Feedbot piece by piece[^1], starting from the smallest
-elements that [fit in head][fits-in-head], then using them as building
-blocks for the actual product, which will flow downstream from the
-[botworks][botworks] V tree.
-
-The first item to be published is S-XML, an XML parser written in Common
-Lisp. Both the name and the code have been lifted from files
-[published][s-xml] by one [nonperson][nonperson] known as Sven Van
-Caekenberghe, who, fortunately, wrote a library that is relatively small
-(around a thousand LoC), is organized so that it can be grasped in a
-relatively short time, and is known to work[^2]. Unfortunately though,
-as with most (all?) heathen programs encountered, this one isn't without
-warts. Thus, in addition to providing a patch, this article discusses
-the structure of S-XML and its current problems.
-
-The patch for S-XML is available in my
-[V source repository][s-xml-v]. Now, as to the library itself, it is
-structured as follows.
-
-S-XML contains three layers of abstraction: a. the core parsing code,
-that reads characters from a stream and returns XML elements, stored in
-`xml.lisp`; b. a series of so-called "wrappers" over the parser that
-take its results and give them a particular structure; and c. an
-interface between (a) and (b), stored in `dom.lisp`. In fact, one could
-say that the layering goes exactly the other way around: the code in (b)
-provides a set of functions for the parser (a), while the parser takes a
-string/stream, processes it and calls the functions provided by (b) so
-that it can decide what to do once it has all the required data,
-e.g. tags, attributes etc. The wrappers in (b) are stored in
-`xml-struct-dom.lisp`, `lxml-dom.lisp` and `sxml-dom.lisp`[^3].
-
-The advantage of this design is that it doesn't constrain the user to
-any particular DOM tree representation. Personally, I find this
-so-called feature to be entirely useless and not much of an advantage
-after all, as I don't have any plans to parse XML files into multiple
-tree formats, not even mentioning the fact that "doesn't constrain the
-user" is the perfect recipe for
-[hallucinated freedom][hallucinated-freedom], and not even discussing
-the extra lines of (mostly dead) code this adds. This
-[cleverness][clever] is more for its own sake than anything of
-substance, and thus eventually some hero or another will surgically
-excise this particular tumour.
-
-Until then, however, the thing works, so it's all the better to publish
-it than to wait for the moment when said hero gets off his or her ass
-and makes the thing shine. Meanwhile, the more pressing matter for yours
-truly, and the next episode of this series, will involve publishing a
-small RSS/Atom parser based on S-XML DOM trees.
-
-[^1]: This style, nowadays immediately recognizable by TMSR citizens as
- the "FFA style", draws from [Asciilifeform][alf]'s
- [Finite Field Arithmetic][loper-os] series.
-
-[^2]: It's been powering Feedbot for some months now.
-
-[^3]: Corresponding, respectively, to a defstruct-based format, Franz's
- [LXML][lxml] format and the so-called [SXML][sxml]. The latter two
- structure XML markup as S-expressions. Currently, Feedbot's RSS
- parser uses LXML, for no reason in particular other than it being
- the implicit option.
-
-[tmsr-schedule-i]: /posts/y05/082-tmsr-schedule-i.html#selection-63.114-63.159
-[intellectual-ownership]: /posts/y04/069-on-intellectual-ownership.html
-[feedbot]: http://btcbase.org/log-search?q=feedbot
-[alf]: http://wot.deedbot.org/17215D118B7239507FAFED98B98228A001ABFFC7.html
-[loper-os]: http://www.loper-os.org/?cat=49
-[fits-in-head]: http://btcbase.org/log-search?q=fits-in-head
-[botworks]: /posts/y05/080-botworks-regrind.html
-[s-xml]: https://archive.is/Ra6bA
-[nonperson]: http://btcbase.org/log-search?q=nonperson
-[s-xml-v]: http://lucian.mogosanu.ro/src/s-xml
-[lxml]: https://archive.is/DpZnN
-[sxml]: https://archive.is/Sl4Ev
-[hallucinated-freedom]: http://trilema.com/2017/the-practical-costs-of-hallucinated-freedom/
-[clever]: http://btcbase.org/log-search?q=clever
--- /dev/null
+---
+postid: 086
+title: An XML parser for Common Lisp programs
+date: March 1, 2019
+author: Lucian Mogoșanu
+tags: tech, tmsr
+---
+
+This post is part of a [series][tmsr-schedule-i] of published
+[artifacts][intellectual-ownership] that (will) represent components for
+The Republic's RSS bot, [Feedbot][feedbot]. The idea behind this series
+is to grow Feedbot piece by piece[^1], starting from the smallest
+elements that [fit in head][fits-in-head], then using them as building
+blocks for the actual product, which will flow downstream from the
+[botworks][botworks] V tree.
+
+The first item to be published is S-XML, an XML parser written in Common
+Lisp. Both the name and the code have been lifted from files
+[published][s-xml] by one [nonperson][nonperson] known as Sven Van
+Caekenberghe, who, fortunately, wrote a library that is relatively small
+(around a thousand LoC), is organized so that it can be grasped in a
+relatively short time, and is known to work[^2]. Unfortunately though,
+as with most (all?) heathen programs encountered, this one isn't without
+warts. Thus, in addition to providing a patch, this article discusses
+the structure of S-XML and its current problems.
+
+The patch for S-XML is available in my
+[V source repository][s-xml-v]. Now, as to the library itself, it is
+structured as follows.
+
+S-XML contains three layers of abstraction: a. the core parsing code,
+that reads characters from a stream and returns XML elements, stored in
+`xml.lisp`; b. a series of so-called "wrappers" over the parser that
+take its results and give them a particular structure; and c. an
+interface between (a) and (b), stored in `dom.lisp`. In fact, one could
+say that the layering goes exactly the other way around: the code in (b)
+provides a set of functions for the parser (a), while the parser takes a
+string/stream, processes it and calls the functions provided by (b) so
+that it can decide what to do once it has all the required data,
+e.g. tags, attributes etc. The wrappers in (b) are stored in
+`xml-struct-dom.lisp`, `lxml-dom.lisp` and `sxml-dom.lisp`[^3].
+
+The advantage of this design is that it doesn't constrain the user to
+any particular DOM tree representation. Personally, I find this
+so-called feature to be entirely useless, as the need to parse XML files
+into multiple tree formats using a *single* library looks like the
+perfect recipe for [hallucinated freedom][hallucinated-freedom], not to
+mention the extra lines of (mostly dead) code added. This
+[cleverness][clever] is more for its own sake than anything of
+substance, and thus eventually some hero or another will surgically
+excise this particular tumour.
+
+Until then, however, the thing works, so it's all the better to publish
+it than to wait for the moment when said hero gets off his or her ass
+and makes the thing shine. Meanwhile, the more pressing matter for yours
+truly, and the next episode of this series, will involve publishing a
+small RSS/Atom parser based on S-XML DOM trees.
+
+[^1]: This style, nowadays immediately recognizable by TMSR citizens as
+ the "FFA style", draws from [Asciilifeform][alf]'s
+ [Finite Field Arithmetic][loper-os] series.
+
+[^2]: It's been powering Feedbot for some months now.
+
+[^3]: Corresponding, respectively, to a defstruct-based format, Franz's
+ [LXML][lxml] format and the so-called [SXML][sxml]. The latter two
+ structure XML markup as S-expressions. Currently, Feedbot's RSS
+ parser uses LXML, for no reason in particular other than it being
+ the implicit option.
+
+[tmsr-schedule-i]: /posts/y05/082-tmsr-schedule-i.html#selection-63.114-63.159
+[intellectual-ownership]: /posts/y04/069-on-intellectual-ownership.html
+[feedbot]: http://btcbase.org/log-search?q=feedbot
+[alf]: http://wot.deedbot.org/17215D118B7239507FAFED98B98228A001ABFFC7.html
+[loper-os]: http://www.loper-os.org/?cat=49
+[fits-in-head]: http://btcbase.org/log-search?q=fits-in-head
+[botworks]: /posts/y05/080-botworks-regrind.html
+[s-xml]: https://archive.is/Ra6bA
+[nonperson]: http://btcbase.org/log-search?q=nonperson
+[s-xml-v]: http://lucian.mogosanu.ro/src/s-xml
+[lxml]: https://archive.is/DpZnN
+[sxml]: https://archive.is/Sl4Ev
+[hallucinated-freedom]: http://trilema.com/2017/the-practical-costs-of-hallucinated-freedom/
+[clever]: http://btcbase.org/log-search?q=clever
projects / thetarpit.git / commitdiff