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Showing posts from August 30, 2009

emacs 23.2 trying to support DOS!

perm url with updates http://xahlee.org/emacs/emacs_supporting_DOS.htmlProblems of Emacs Supporting Obsolete SystemsXah Lee, 2009-09-03Emacs people are trying to make emacs still working on DOS, a technology that has been practically obsolete for about 10 or 15 years. http://lists.gnu.org/archive/html/emacs-devel/2009-08/msg01214.htmlWhat a idiocy.The problem is that nothing you or me can do about it. If you join the dev list, even if you are recognized as having made major contributions to emacs, your opinion or suggestion on this will be debated in the list. (in emacs dev community, and probably many FSF dev communities, you are nobody, and can never be proven otherwise, unless you are Richard Stallman, who has been out of touch with coding for perhaps 15 years) Typically, at the end, nothing will be done, or some other compromised botched up shit will be taking place.The support of obsolete technologies do harm. In this case, forcing file names to DOS's 8 chars plus “extension”…

Math Notations, Computer Languages, and the “Form” in Formalism

perm url with updates: http://xahlee.org/cmaci/notation/index.htmlMath Notations, Computer Languages, and the “Form” in FormalismThis page is a collection of essays and expositions on the subjects of nomenclature and notations in math and computer languages, in the context of facilitating human communication and theorem proving systems.Most of these essays here are originally from email, blogs, or rants. They are not of publication quality, and they are not a coherent exposition the subject. Here's a very brief summary of of these essays's central thesis:• Traditional math notations are very inconsistent. Edsger Dijkstra is a leader in a movement of what's called Calculational Proofs. That is, using a notation that is consistent and facilitates the calculation aspects when doing math by humans.• Today, especially since 1990s, tremendous advances are made in computer algebra systems and theorem proving systems. In these languages, a coherent syntax, grammar, are needed for…

SubVersion Basics

perm url with updates: http://xahlee.org/UnixResource_dir/svn.htmlSubVersion TutorialXah Lee, 2009-08-28This page is a quick start tutorial of using SubVersion (SVN), a version control system.Basic Check Out, CommitWhat commands are available?Type “svn help”. How to checkout a project?cd to a directory where you want the files to be. Then do for example: svn checkout svn://vmm.math.uci.edu/transvections svn checkout svn://vmm.math.uci.edu/ svn checkout https://emacs2010.googlecode.com/svn/trunk/ ErgoEmacs --username xahlee How to commit a change?Once you checked out, made your modifications, then you can check back in (commit your changes). To commit, cd to the working dir, then do: svn commit -m "some one-line message summary of what you changed" How to Add or Remove a dir or file?If you created new files in your working copy and committed it, that won't work. You will need to run a svn command first to add or remove a file or dir, then commit.To add, use the add command:…