APL in Email

Introduction

As others have already noticed, Unicode is perfect for exchanging APL information in email because the entire APL character set is included in the Unicode spec. However, there are several issues to deal with. For reasons which will become obvious shortly, I'll focus on the Mozilla Thunderibrd email program.

Displaying APL Characters

The first issue is the display of incoming messages containing APL characters. Of course, you need a Unicode font, but if you care about the appearance of the APL glyphs, then not just any Unicode font will do. APL vendors and other APL font mavens have provided several excellent choices. Two free and attractive APL Unicode fonts are SImPL (Unicode) and APL385 Unicode, both of which are listed at the top right of this page. Your APL vendor might also supply an APL Unicode font.

Next, you must specify that your APL Unicode font is to be used to display messages. This can be done easily in Mozilla Thunderbird, however in one of the sections below I propose a different way to do this, so I don't recommend changing this setting directly. In fact, to display non-APL plain text (monospaced) messages, I suggest using an attractive font such as Monaco. For more choices of monospaced programmer's fonts, see here.

At the same time, we all need to agree on a common encoding for exchanging messages. A generally accepted solution is to use the Unicode encoding of UTF-8. As with all Unicode encodings, this one can display the full APL character set. Moreover, UTF-8 has the advantage of not needing extra padding for the vast majority of text (7-bit ASCII) found in plain text messages.

In Mozilla Thunderbird, character encodings are specified from the Tools menu, select Options, and then Display, Formatting, and Fonts.... In the section Character Encodings, select Unicode (UTF-8) for both Outgoing Mail and Incoming Mail. There is no need to check the box labeled Apply the default character encoding to all incoming messages as this can mess up the display of messages with a different encoding. However, do check the box labeled Use the default character encoding in replies as this will allow you to enter APL characters in your response. However, doing so might cause any quoted text to display oddly if it doesn't use UTF-8 in its encoding. C’est la vie.

Exit this dialog by clicking the next two OK buttons.

Typing APL Characters

There are several ways to enter APL characters into an email message.

• IBM bundles an APL keyboard handler for Windows with its APL2 product. With this program, you can enter APL characters in their Unicode UTF-16 encoding into any Windows program that supports Unicode.
• Dyalog bundles a similar program for Windows and Linux.
• Keep a Unicode-based APL intepreter open in another window, enter the APL expression there, and copy/paste into the email program.

A Thunderbird Extension

However, if you use Mozilla Thunderbird on any of its platforms (Windows, Linux, Mac OS, etc.) as your email program, there is another solution. One of the beauties of Mozilla's products is that they allow programmers to write extensions to the base program to provide additional capabilities which then automatically extend to all its platforms.

This particular extension does two things:

• It allows you to enter APL characters just as you would inside an APL interpreter. For example, if your interpreter uses Alt-j to enter a jot (∘), then that same keystroke in Thunderbird's message compose window produces the same character.
• It allows you to switch between using a monospaced APL font or another font for the display of plain text messages. As there is (to my knowledge) no freely available proportional APL Unicode font that contains all of the APL glyphs currently in use, this feature works on plain text messages only.

Download and Install

To install this extension in Thunderbird,

1. Right click aplchars.xpi and choose Save Link As... in Firefox, or Save Target As... in Internet Explorer, or the appropriate menu item in another browser.
2. Choose and remember a place to save the file.
3. After the file has downloaded, bring up Thunderbird.
4. From the Tools menu, select Add-ons.
5. In the Add-ons window, select the Extensions tab.
6. Click the Install button.
7. Locate and select the file you just downloaded.
8. Click the Install Now button.
9. Click the Restart Thunderbird button.

Configure

Keyboard Layout and APL Font

This extension supports multiple APL keyboards and multiple APL fonts. Here's how to specify your preferences.

1. In the main window, from the Tools menu, select APL Chars Options....
2. Select the keyboard layout.
3. If your choice for a keyboard layout is not listed, with the complete details including the name of the keyboard layout, along with a list of each keystroke (e.g., Alt-e) and the name of the corresponding APL character (e.g., epsilon). Note that Alt-E (that is, Alt-shift-e) might map to a different APL character (e.g., epsilon-underbar).
4. Select the monospaced APL Unicode font you'd like to use when displaying plain text APL messages.
5. If your choice for a monospaced APL Unicode font is not listed, with the font name and a publicly available download link.
6. Click the OK button.
7. For a visual display of the NARS2000 keyboard, see this page.

Main Window Toolbar

1. In the main window, right click the toolbar and choose Customize....
2. Scroll down in the Customize Toolbar window until you see two icons both labeled APL Font In Use. The behavior of the two icons is the same, but they are different sizes: Normal and Large. Choose the one whose size matches the other icons on the toolbar, and click and drag it onto the toolbar placing it wherever you prefer.
3. Back in the Customize Toolbar window, click the OK button. Do not click the Red X (close window) button as this discards your changes.
4. At this point, depending upon the internal state, the newly added button might change its image and label to indicate that the APL Font substitution is not in effect.

When displaying a message with APL characters, click the Other Font In Use button (it'll change the image and it'll change the label to APL Font In Use). To display the plain text message using the previously selected font, click the APL Font In Use button (it'll change the image and it'll change the label to Other Font In Use).

Compose Window Toolbar

1. In the main window, click the Write button as if you were about to compose a message.
2. Right click the Compose window toolbar and choose Customize....
3. Scroll down in the Customize Toolbar window until you see two icons both labeled APL Translate ON. The behavior of the two icons is the same, but they are different sizes: Normal and Large. Choose the one whose size matches the other icons on the toolbar, and click and drag it onto the toolbar placing it wherever you prefer.
4. Back in the Customize Toolbar window, click the OK button. Do not click the Red X (close window) button as this discards your changes.
5. Back in the Compose window, close it.

To toggle APL Character Translation on/off, click the APL Translate button.

A Glitch

There is one very minor shortcoming: normally, within the message compose window, the keystrokes Alt-r and Alt-s are shortcuts used to select the locations for the From and Subject lines, respectively. Because, those shortcuts overlap with APL characters on some keyboard layouts (e.g., ⍴ and ⌈), when this extension is present, those keystrokes may be interpreted as APL characters instead of shifting the focus to the above-mentioned locations.

Similarily, the Alt- keystrokes for the message compose window menu (e.g., Alt-f for File) might overlay the keystrokes for some APL characters. In this case, there is a simple workaround: press and release the Alt- key and then press the desired letter (e.g. f).

Copyright, License, & Source Code

This program is Copyright 2008-2011 © Sudley Place Software, and is released to the public as Free Software licensed under an agreement called the GNU GPL (General Public License), Version 3 or any later version.

The source code may be found in the NARS2000 SVN database for inspection and improvement.

Fonts

If you have trouble displaying the APL characters on this page, likely it is due to either a browser setting (or an out-of-date browser) or a missing font. Both Mozilla Firefox 2.0 or later and Internet Explorer 7 or later display the APL characters perfectly, but IE6 has some trouble. If this page doesn't display well with either APL Unicode font using any version of Internet Explorer, please try it again with Mozilla Firefox. Links for the two APL Unicode fonts as well as for Mozilla Firefox appear at the top of this page.

Author

This page was created by Bob Smith -- please any questions or comments about it to me.

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