mirror of
https://bjh21.me.uk/bedstead/.git
synced 2026-07-09 21:43:06 -04:00
9f2acba7bd
Unicode takes the position that U+0027 APOSTROPHE is always a straight apostrophe and is you want a curly one you should use U+2019 RIGHT SINGLE QUOTATION MARK (or U+02BC MODIFIER LETTER APOSTROPHE but let's not get into that here). Bedstead generally follows that, putting the SAA5050 straight apostrophe at U+0027 and the SAA5055 curly one at U+2019. Older character standards, though, conflated those two and treated the difference between them as one of font design. In particular, ETS 300 706: May 1997, "Enhanced Teletext specification" treats position 2/7 as being the same character in all national sub-sets of the Latin G0 primary set. When coverting Teletext data to Unicode, ZVBI maps 2/7 to U+0027 whichever national sub-set is in use. This means that to faithfully display Teletext data in the way that an SAA5051/2 would, Bedstead needs to interpret U+0027 as a curly apostrophe. I have accomplished this by adding a new "apostrophe.curly" alias and including that in the 'ss01' and 'ss02' Stylistic Sets. It also, of course, gains a new Character Variant feature, 'cv07', so that you can turn the curly apostrophe on and off independently. This does cause me to wonder whether there should be a stylistic set to map U+0020..U+007E onto the SAA5055 glyphs.
