[css-ruby] Autohiding Controls Needed

CSS Ruby needs autohiding controls for inter-language ruby to allow 
autohiding of non-matching strings. Some of the redundant combinations 
I've run into:

  * " " (English space) → (no text in Chinese/Japanese)
  * " " (English space) → "・" (katakana middle dot)
  * "" (no text in English) → "・" (katakana middle dot)
  * "-" (quasi-English compound word) → "" (no text in Japanese)
  * ": " (English colon plus space) → "〜" (Japanese subtitle start)
    (wave dash)
  * "" (no text in English) → "〜" (Japanese subtitle end) (wave dash)
  * "✱" (English asterisk) → "✱〜" (Japanese asterisk item start)
    (asterisk plus wave dash)
  * "" (no text) → "〜" (Japanese asterisk item end) (wave dash)
  * " " (English adjective/noun space) → "の" (Japanese particle no)
  * " = " (English spaced equals sign) → "×" (Japanese unspaced equals sign)
  * " × " (English spaced multiplication sign) → "×" (Japanese unspaced
    multiplication sign)
  * "" (no text in English) → "-" (Japanese title hyphen start/end)

It'd be nice to have something like...

ruby-autohide: match("", "-", "\2010", "\2011", "・", "〜") match(" ", "", 
"・", "の") match(": ", "〜") match(" = ", "=") match(" × ", "×") 
match("✱", "✱〜");

... where match() takes one argument matching ruby base content and 
autohides ruby annotations with content matching any of the subsequent 
arguments.

(U+2010 and U+2011 are hyphen and non-breaking hyphen characters, 
respectively.)