Note that this creates an opportunity for encoding something else ! Carets are really true glyphs which should be shown consistantly with the fonts used in the text content. This glyph is drawn usually on top of this text (not always, it could also be inserted as an additional "character", pushing the text around it to make it fit). It has its own identity (as a caret), but could ultimately be any kind of symbol.
Some caret forms are well known : the vertical line and rectangular block being the most common. When it is a rectangular block displayed on top of characters, its size (notably its width) should be the same as the character over which it is inserted (notably when this caret is used for edition of text in "overwrite" mode, rather than insertion mode where the thin vertical line is recommanded). But why not encoding these carets are true symbols ? Some of them may be script specific. But with this encoding, the carets found in fonts would adopt the correct form according to the font design (for example fonts in italic or oblique styles would map an italic or oblique glyph of their carets). It would be even better than trying to infer a caret form from a few font-level properties (like the average character width, or the average angle of italic, i.e. the main direction of ascenders and descenders, someting which is not always consistant between all glyphs in a fontn and that would promote another more usable caret form than just a slanted line, including even the possibility if using horizontal carets with a much smaller ascender or descender, or just displaying an arrow head). I don't want here to pormote specific forms of carets, but instead the encoding of some abstract classes of carets: - a direction neutral caret, and two oriented carets (one for the left-side, another for the right side) - each one in two kinds : one for the overwrite mode, another for the insertion mode. In other words: a total of 6 kinds of carets (or possibly just 4 if the direction neutral caret can be represented by the left-side caret and the righ-side caret, so that it will display an orientation only within bidirectional texts, and fonts for Latin will typically map only a vertical line or block for the right-side insertion caret that normally appears after the last character typed or at the beginning of text, and the left-side overwrite caret would be a basic rectangular block). These 4 or 6 characters would be encoded only as abstract symbols, without any dedicated form (the representative glyphs could be chosen using the Arabic script, in its modern non slanted form, as a guide, using metrics compatible with Latin, Greek, Cyrillic, and probably sinograms and Hagul as well). They could appear in isolation in plain text (where they would not be flashing, but where they could adopt other styles like bold, italic, colors, outer borders and decorations like underlines and overlines) for use in documentation. When editing Latin texts (and other simple LTR alphabetic scripts, or sinograms and generic LTR symbols), we usually use either : - the right-side insertion caret as a "vertical" line, possibly slanted (if a direction is displayed with an arrow head, it points to the right) - the lef-side overwrite caret as a rectangular block, possibly slanted (if a direction is displayed with an arrow head, it points to the right, the arrow head being connected to the left side of the rectangle and pointing within the rectangle) The 1st one is the most frequently used (we generally work in insertion mode in most editors). 2012/11/12 Philippe Verdy <[email protected]> > Carets in bidirectional texts CAN be oriented (meaning that they are not > necessarily BETWEEN characters, but possibly BEFORE and/or AFTER them). > > Have you seen how the caret behaves in Java applications ? It shows an > extra triangular arrow head, oriented to the left or right, and connected > to the top of the vertical line. And it is then really appearing NEARBY the > character it designates in the indicated direction. > > For more complex scripts, the form of the caret could be more complex (if > we could position within an Hangul syllabic square, it would have to take > the form of a corner indicating where in the composition square is the > previous character, the corner being at the position where the syllable > will be modified by the insertion of an additional character. > > Carets are not necessarily a simple line or block. > > 2012/11/12 QSJN 4 UKR <[email protected]> > >> I have a little advise for the text editor designers. I think i am >> either the stupidest or the smartest man in the universe if i write it >> :( >> A caret is a flashing line, block, or other picture in the client area >> of a window, it indicates the place (between two characters) at which >> text will be inserted (or the edge of the text to be selected or >> deleted). What does it mean? Between? There is no "between" in the >> bidirectional text, the previous and the next character are not >> necessary nearby! > >
