Digital Shwa

Encoding

From the human point of view, a Shwa text is a sequence of half letters. But from a digital point of view, a Shwa text is a sequence of full letters. In other words, the Shwa encoding is essentially Alphabet Gait. Not only is it complete and compact, but unsophisticated rendering engines will still produce legible output.

Shwa is encoded in the Private Use Area of Unicode, starting at E000 and ending at E1FF. This makes Shwa compatible with Unicode (and the SIL PUA) but not part of it. Since Unicode is not allowed to change, it won't be appropriate to encode Shwa directly in Unicode until it stops evolving.

Here is the complete set of codepoints, with unused codepoints in gray:

The hexadecimal numbers at top left, top and left add up to indicate the code point of the letter in each cell. For instance, the Shwa n is at code point E150.

The Shwa symbol is at E1C4, as if it were spelled by its two components.

The Shwa dot is encoded (at #E070) separately from the normal Unicode space (at #0020). The rule is that the space between Shwa text and other text is the normal space, but the dot is used within Shwa text. That confounds the non-Shwa end-of-line algorithms so that lines of Shwa text in Alphabet gait are right-justified. The other gaits may have to leave an extra space or two at the right side of a line.

Digital Gaits

In Shwa, the gaits are implemented using Advanced Typography - either OpenType or AAT. These specify features which perform substitutions or positionings of glyphs in certain circumstances. For example, in Syllabary gait, a sequence of consonant+vowel is replaced by the corresponding kana. The feature set is rich enough for everything Shwa needs. Most of what is needed is support for ligatures.

Since gaits are implemented as fonts, there's no need for special treatment during text entry, transmission or storage. Shwa text can be searched and sorted without regard for gait, and foreign words in text that can't be written in the gait of the text will appear in Alphabet gait.

Shwa fonts include keywords that identify their gait, as follows:


< Letter Reference Keyboard >


© 2002-2016 Shwa shwa@shwa.org 29jan16