[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: Unix/Java design issues (Was: Re: Is CDATA "structure"?)
John Cowan wrote: >Java doesn't have unsigned arithmetic values (and type *byte* is >meant to be arithmetic) because they have all kinds of surprising >results if misused: see the relevant sections of _Writing Solid C_. >The purposes served by unsigned bytes are better served by characters; >you can't just cast bytes to characters, though, but need to use >c = b < 0 ? b + 256 : b instead. I understand Java's intent re the *byte* type, and i agree that Java's use of Unicode is a long-overdue move to non-Anglo-centric computing. However, since i've been writing rock-solid C code for almost 20 years, i've long observed a common programmer laziness concerning all numeric types -- namely the non-use of the "unsigned" qualifier for inherently unsigned numbers (e.g. file offsets, binary file contents). The former example created an unnecessary 32KB (and later 2GB) limit to file sizes handled using the standard C library. The latter example is still an issue today -- at least for those whose computing environment includes low-resource embedded systems and/or legacy byte-oriented data formats. I beg to disagree that 16-bit characters are always the better approach when dealing with byte-oriented data. It is true that modern 32- and 64-bit processors don't handle mere bytes as efficiently as the 8- and 16-bit procs of old, and thus should use 16-, or even 32-bit, chunks as the base unit of data. However, if Java is going to cover the world, including embedded systems (e.g. the Java coffer-maker), compact byte-oriented data formats will continue to be useful, and i'd hate to have to execute "c = (b < 0 ? b + 256 : b)" every time i wanted to read a single byte. And yes, i do stand guilty of spending too much time with 6805's and such, and not enough with Alphas and Pentiums [sigh]. >[snip] >As for "TTY legacy", real Teletypes (at least models 33/35) >want CR/LF, not just LF. After learning to program using 80-column Hollerith [sp?] cards, i was delighted to move to state-of-the-art interactive programming using a TTY (with paper tape!) -- the TTY comment pertained to 7-bit characters -- not text record delimiters. Regards, -Nik O, Content Mgmt Solutions, Jackson, Wyo. xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1 To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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