Custom ligatures and lenited consonants in old gaelic text

Apologies if this is a stupid question (or already answered), but I’m trying to create ligatures outside of the standard latin range. In old gaelic (Irish) certain combinations such as bh, ch, dh, fh, gh, mh, ph, rh, and th would have been written as b with a tittle, c with a tittle etc. Should I be looking at discretionary ligatures or alternates? Diacritics don’t seem to offer any specific support.

I realise this is an odd request, there are not many Irish speakers, still less who write using the older text, but it’s something I’d like to preserve if possible.

Any and all suggestions are welcome.

There is bdot and so on. They are not ligatures, they are completely differrent characters, different ways of writing the same thing. No need to set up an OT feature, just add the respective glyphs.

Thanks for the quick response. Do I add these as extra symbols? Ideally, I’d like the lenited symbols to appear if someone types any of the combinations above, rather than them typing using alt/shift etc. Hope that makes sense.

Shouldn’t be done. If you do that, you are breaking the character/glyph distinction. If you want to turn bh into bdot, that is a change in the characters, and should therefore not be done in the font, but with search and replace in the text editor.

If you’re unhappy about how the letters are typed, consider making a keyboard layout with Ukelele.

Do we not do that already with ligatures/discretionary ligatures? IE: replacing two characters with one? In this font I’d like to treat bh etc as ligatures or alternates rather than forcing the user to install a new keyboard layout.

Apologies for my ignorance in this area, I’ve googled bdot with no useful results.

No. A feature replaces glyphs, not characters. It is not a good idea to mess with user input.

You will find b with dotaccent and the other glyphs for Gaelic in Window > Glyph Info, and in UnicodeChecker.

Read these please:

I think, for scripts that have no proper support in apps and keyboards, substitutions like that are acceptable.

Irish Gaelic is well-supported. macOS comes preinstalled with an Irish and Irish Extended keyboard that let you type dotted letters (see below). Most system fonts have those letters in their glyph set, too. So, no one needs to install a keyboard layout or a font. It already works.

IOW, I don’t see the necessity to break something that works exactly as it is supposed to work already.

If that is the case, I retract my post.

Sorry for the slow reply and thanks for your response. That’s exactly what I was looking for.

The letter+h method is the new modern ortography. The old orthography with dotted consonants (and other peculiarities, like the dotless i) is no longer used. As others have noted, it is not good to change the text data with the font. Irish Gaelic also requires the ⁊ – the tironian et – and kerning for both sides of the capitals against prefix minuscles.

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Hi Frode. Yes, I know. However I live in a Gaeltacht area of native Irish speakers and the lenited consonants are still in use, particularly in signage and shopfronts. This project is not intended to match the modern orthography, rather to preserve the older methods which had an unique beauty to my eyes.


Hi Matt! I’m familiar with the Gaelic road signs, street signs & shop lettering. Can I drop you an email offline? Any chance to get more familiar with this stuff is most welcome.

No problem Frode. I’m new to this forum, though, not quite sure how to pass along my email.

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Terrible kerning on that first sign, by the way :wink:

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Most fonts don’t have these lenition diacritics, although they have been introduced with Adobe Latin 5 Character Sets.

For the Irish language user who wishes to type bdot, using search and replace isn’t ideal. There will be a search and replace somewhere along the line anyway, is it a hack to use OT features to form bdot on the fly?

Please reread what is written up there. Many fonts have these letters already, and the Irish keyboard just lets you type them like any other letter. There is no reason for an OT hack.

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Can you expand on using the Irish keyboard please? I’ve set up bdot etc as you’ve described, but only seem to be able to type the lenited consonants by inserting special characters from the emoji and symbols palette on the menu bar.
It works, but is not ideal for the casual user.

  1. > System Preferences > Keyboard > Input Sources

  2. Click on [+] to add the English > Irish and/or Irish > Irish Extended keyboard. (Note: many other extended keyboard layouts support dotted letters as well, e.g., ABC Extended and US Extended, etc.)

  3. Make sure the option Show Input menu in menu bar is turned on.

  4. From the menu bar in the top right corner on the screen, choose one of the Irish keyboards:

  5. Type Alt-W for the dot, followed by the letter you want dotted, e.g., b. These letters I typed with the Irish Extended keyboard: ẇṡġḣḃ

UnicodeChecker can give you the list of all installed fonts that support a certain Unicode. So, e.g., search for latin b with dot above and open the fonts menu. You will see something like this:

I would say that is a pretty long list. But please judge for yourself.

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Thanks Mekkablue. I’ve done as you described, but while I have an Irish option, I don’t have an Irish extended. Is that an extra installation under El Capitan?

[Edit] Facepalm. Ignore the above. I’ve found the extended keyboard. Thanks for your help.

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