I am designing a font with some special characters like different types of arrows. I know that I could use any free space in a font map to place them but I would like to know which characters are the most suitable to place them so they are:
- Easy to find for a future user
- Easily accessible on the keyboard
I'm working with FontLab and for the base design, I'm temporarily using MacOS Roman character set.
• Easily accessible on the keyboard …
Here are search results for arrows in Unicode:
Note that those results include all the arrow characters in Unicode including those used as symbols or combining marks in phonetic transcription systems and other forms of semantic text. You will need to look through the results to find the ones that make sense to map to your glyphs.
Also take a look at the Unicode glyph charts specific to arrows:
Miscellaneous Symbols and Arrows
$ uni search ARROW | wc -l
there are 618 characters found with ARROW in the name. 174 of them are Math_Symbols.
I wouldn't expect that the current assertions in Unicode are not enough. But there are still some symbols (alchemy, pharmacy, botany) which are used in printed books but don't have a Unicode code point.
Technically a glyph does not need a codepoint in a font. Using the PUA is a last resort and problematic in many ways. But if the PUA is used, why not also support them via OT functions. You can support both.
But in any case don't misuse other codepoints for keyboard convenience. E.g. asserting long_s to $, or mapping Hebrew glyphs to ASCII letters (such fonts still exist), as this did a lot of harm and destroyed data. As a font designer you should care about input methods. There are still many possibilities to input special characters like HTML sequences, special escape sequences like TEX does, virtual keyboards, character pickers etc.
In any application with a “glyphs” palette (nothing to do with the font editor), a group of arrows will be easy for users to find.
Characters such as the primes are much harder to locate!
In FontLab, go to Index mode and move the arrows to the end of the window (if not already there), to make them especially obvious in glyphs palettes.
Now, those font-format specs don't specify what numeric character codes should be used, and they don't clarify how text using those fonts should be represented in documents. So, that's a bit of a hacky "wild west".