(ascii-graphic? char) -- all non-control ascii chars, including space.
no other whitespace characters.
This is just the negation of ascii-control?, and traditionally Scheme doesn't do these: we have various kinds of identity/equality, but no built-in negations for them, unlike the = or == versus <> or != or /= in other languages. I would propose simply dropping it, especially because the name is problematic (CL pulls one way, Posix another).
(ascii-space-or-tab? char) -- does what it says on the tin. alternative
names: `ascii-blank?` (too ambiguous) and `ascii-horizontal-whitespace?`
(clear, but too long).
In traditional RFC terminology this is "hwsp", but that may be too obscure now. I guess space-or-tab is as good as we can get.
(ascii-punctuation? char) -- all punctuation and "symbol" characters, as
the distinction between those is completely arbitrary to a layperson.
I just posted about this, suggesting ascii-other?.
SRFI 14 (which may or may not be replaced for R7RS-large)
It won't be replaced unless someone else makes a motion to that effect and it's voted in. The only real problem with it is the rules for assigning Unicode characters to standard character sets. I've written a post-implementation note that points to a detailed explanation: see <
https://github.com/johnwcowan/srfi-14>.