— Scheme Procedure: char-set-cursor cs

Return a cursor into the character set cs.

— Scheme Procedure: char-set-ref cs cursor

Return the character at the current cursor position cursor in the character set cs. It is an error to pass a cursor for which end-of-char-set? returns true.

— Scheme Procedure: char-set-cursor-next cs cursor

Advance the character set cursor cursor to the next character in the character set cs. It is an error if the cursor given satisfies end-of-char-set?.

— Scheme Procedure: end-of-char-set? cursor

Return #t if cursor has reached the end of a character set, #f otherwise.

— Scheme Procedure: char-set-fold kons knil cs

Fold the procedure kons over the character set cs, initializing it with knil.

— Scheme Procedure: char-set-unfold p f g seed [base]

Return a new character set constructed as specified by procedures p, f, and g, given an initial value seed. More precisely:

• g is used to generate a series of seed values from the initial seed: seed, (g seed), (g^2 seed), (g^3 seed), ...
• p tells us when to stop — when it returns true when applied to one of these seed values.
• f maps each seed value to a character. These chars are added to the base character set base to form the result.
• base defaults to the empty set.

— Scheme Procedure: char-set-for-each proc cs

Apply proc to every character in the character set cs.

— Scheme Procedure: char-set-map proc cs

Map the procedure proc over every character in cs. proc must be a character -> character procedure.