Log of changes on this site
August 2002 through July 2003

Please refer to ChangeLog.html for the most recent changes

July 4, 2003

• Non-linear matching and efficient (cyclic) unification on ordered trees (terms)
• A new page An applicative-order term rewriting system for code generation, and its termination analysis: generating efficient median filters

June 1, 2003

• The benchmarks in Comparing SSAX and Expat XML parsers in features and performance now reflect the latest version of SSAX, which underwent a few performance improvements. The benchmarks show that a large, practically relevant, purely referentially transparent Scheme program, an XML parser, runs measurably faster than an equivalent C program. It seems safe to say that Scheme is not an inherently slow language and can deliver competitive performance.
• New SXSLT stylesheet binding: *macro*. The new version of the traversal combinator pre-post-order is also more efficient. For more details, see a message "SXSLT improvements" on the SSAX-SXML mailing list (25 Apr 2003).
• The stylesheet to produce the SXML specification now takes a notable advantage of the new stylesheet *macro* binding.
• quote -- as a macro

May 4, 2003

• A new page Number-parameterized types and decimal type arithmetics
• A new page Attractive Types
• Martin Gasbichler has kindly ported Treaps and the bit reader to Scheme48 so they could be included in the Scheme Untergrund Library.

April 4, 2003

• An article On parent pointers in SXML trees
• Limitations of threads, and other summaries from USENIX 2002
• A dark, under-specified corner of R5RS macros

March 1, 2003

• Added an example of the exhaustive parsing of nested strings to the sample code of the input parsing library
• A solution to a bluff combinator problem in Lambda calculus
• Curious properties of particular lambda-terms

February 7, 2003

• Added a paper A better XML parser through functional programming, a transcript of a talk SXSLT: Manipulation Language for XML and an advanced SXSLT tutorial to SXML Papers and Presentations
• Added two sections on Generators in Python, Icon and Scheme and on cursors vs. lazy lists to General ways to traverse collections
• A new section XML pull parsing and SSAX points out how iteration inversion can turn SSAX into an XML Pull Parser

January 1, 2003

• A practical Lambda-calculator in Haskell, which implements a normal-order evaluation as a bottom-up parsing
• P-numerals: arithmetically more convenient and efficient numerals than Church numerals. P-numerals are a functional equivalent of a list data structure.

December 1, 2002

• Reorganization of the XML and Scheme page. Added references to the ILC2002 paper and the talk "XML, XPath, XSLT implementations as SXML, SXPath, and SXSLT". Added many references to the complete examples of using SSAX and SXSLT. Added a better documentation for the pre-post-order function; added a description of a replace-range function.
• Version 4.4 of the Basic Linear Algebra and Optimization classlib. The library now compiles with GCC 2.95.x and GCC 3.2. The package has several complete examples. The README file expands the description of LAStreams and compares them with C++ iterators.
• More detailed comparison of various macro-expanders, with respect to the stress test of the syntax-rule macro-expander

November 10, 2002

• Macros that Compose: Systematic Macro Programming [PDF] The transcript of a talk presented on October 7, 2002 at GPCE 2002: an ACM SIGPLAN/SIGSOFT Conference on Generative Programming and Component Engineering
• A stress test of the syntax-rule macro-expander

October 11, 2002

• An enhanced collection of CGI processing utilities. The most notable addition is a procedure CGI:lookup.
• Parsing of MIME Entities
• Running an HTTP transaction

September 1, 2002

• Version 2.5 of the SXML Specification. Most notable additions are the first-class status for aux-list, detailed discussion of the namespaces in SXML and, a greatly expanded section on SXML normal forms.
• Pure-functional transformations of cyclic graphs and the Credit Card Transform

August 4, 2002

• Added a section on drawbacks of a sort-based shuffle algorithm to Provably perfect shuffling
• Doubts about the concept of information: added a reference and a summary of an article demonstrating that DNA is a rather incomplete code for life
• A Scheme -to- syntax-rules compiler, a tool to systematically develop complex syntax-rule macros

August 2001 through July 2002

December 1995 through August 1996