Le 07/01/2011 19:16, Luis Rivera a écrit :
On 7 January 2011 07:17, Ulrike Fischer<[email protected]> wrote:
Am Fri, 7 Jan 2011 11:38:26 +0100 schrieb Philipp Stephani:
BTW, you should _not_ do something like replacing ^c by ĉ. If you
want ĉ, type ĉ. Use a keyboard layout that contains that
character, an input method, or some auto-correction function of
your text editor, but don't transform text while processing.
In general I agree, but there are some cases where I prefer not to
input the real char. -- and --- are such cases. Even if – and —
where easier to input on my keyboard: I have difficulties to
distinguish -, – and — in my editor(s).
Btw: I think this type of "fake ligatures" (-- to –) could be used
for the translation discussed here. One would naturally have to
enable ^ in text mode (along the way _ is enable with
underscore.sty). The translation could then be enabled by font
switches.
The Greek input encoding in cbgreek, lfb and ibycus fonts use the
ligature system from Metafont to implement the transliterations; a
similar approach is done with the virtual fonts of bgreek: so I am
very keen on understanding how ligatures work in LuaTeX. A reference
to a primer on this subject is surely welcome.
Ligatures work roughly like in TeX, i.e. chars have a ``ligatures''
field (see for instance pages 145-6 or the manual), which triggers a
ligature if they're followed by the right glyph. And the only way to
control that is to control font creation, where the field is defined
(i.e. when you load a font you have to define a ``ligatures'' field for
"^", etc.). That can't be done after the font has been loaded; I don't
know if the latter restriction is definitive or if LuaTeX will perhaps
someday evolves to allow font tweaking in real-time (that'd be nice e.g.
to switch between number styles).
Another (probably simpler) approach is to use a callback, most likely
the "hyphenate" callback (so hyphenation can be properly done
thereafter), spot all "^" glyphs and replace them according to the glyph
that follows. That's handmade ligature, so to speak.
Best,
Paul
