Other Methods
APL Character Set and
Browsers
Other Methods
There are several other methods and variations for handling the APL character set in a browser.
HTML 4 Character Entities
The following method is not available generally now, but is certainly worth following for future consideration. It is summed up in the following quote from "HTML, Programmer's Reference", by Thomas A. Powell and Dan Whitworth, Osborne / McGraw-Hill, 1998.
The HTML 4 specification specification introduces a wide array of new character entities, including additional Latin characters, the Greek alphabet, special spacing characters, arrows, technical symbols, and various shapes. Some of these entities have yet to be supproted by browser vendors. Netscape 4 only supports a few of the extended Latin characters ... Microsoft Internet Explorer supports many of these entities, including the Greek alphabet and mathematical symbols.
The following examples are supplied for illustration and testing. The word describes the symbol according to the HTML 4 specification, but the specified symbol may not be correctly displayed in your browser at the current time.
- epsilon ε
- theta θ
- iota ι
- rho ρ
- membership ∈
- left arrow ←
- floor ⌊
- HTML and XHTML, The Complete Reference, by Thomas Powell. The publisher has made freely available large chunks of the book on-line, including the chapter on special characters.
Large GIF's
Given that GIF's are universally supported in browsers, create a GIF of the entire text (or a large part of it) that contains the APL characters, for example, one GIF showing an entire function. The GIF could be created by, for example, a screen capture, which leads to the question - what is a suitable choice of software or technique to "capture" part of a screen? (Windows, MacIntosh, or Linux)
One user reports:
JPEG is good for colour photos. GIF is better for monochrome or few colours. PMView (OS/2 and Windows) does captures nicely as does Paint Shop Pro (Windows).
Here is a simple Windows method to create a large GIF of any text.
- Display in a window the text to be made into a GIF. (This could be APL text in the Session Manager window, or whatever.)
- Press the "Print Screen" key. (This actually puts the screen image in the Clipboard.)
- Open any common graphics program such as Paint.
- Paste into the Paint window.
- Cut out the part of the image you want (and adjust as desired.)
- Save as GIF (or BMP or JPEG).
For an example of a highly readable document using larger GIF images to display mathematical expressions (not APL, but the same principle applies), see http://ralph.bucher.home.att.net/project.html .
At the APL2001 conference it was reported that one major web site used a program to compute a GIF image of an entire APL expression or function (which was done dynamically at the server) and then the browser downloaded the GIF to the workstation.
(If using individual GIF's to represent individual APL characters is similar to using "movable type", then using a GIF to represent an entire expression may compared to carving the entire page in one wooden block.)
latex2html
One contributor recommends starting with "latex", a standard based on the Tex typesetting concepts.
For mathematics, the standard is latex2html. You start with a latex document, and the (perl) code formats it and makes GIF's of the tricky bits. (It's used also for multilingual documents on the web.)
For example, http://www-texdev.mpce.mq.edu.au/l2h/docs/manual
A new, similar code (also free) is latex2slides http://udel.edu/~lmilano/latex2slides/
See also [ Snake Island Research ] on APL and Latex.
PDF format
Embed APL code in PDF ("Adobe") format file to be displayed in the browser. This requires the author to have the Adobe Acrobat software or equivalent, and the browser (software and human) to have the Adobe Reader (commonly and freely available).
One user reports:
One can use freeware to produce PDF, e.g. ghostscript, pdftex. If you want everyone to be able to read it, [this method] is just about guaranteed.
Some problems (and solutions) with using APL in PDF format have been reported in the newsgroup comp.lang.apl. [ Access the newsgroup ] and search with the string "PDF".