(guile.info.gz) SRFI-14 Iterating Over Character Sets
Info Catalog
(guile.info.gz) SRFI-14 Predicates/Comparison
(guile.info.gz) SRFI-14
(guile.info.gz) SRFI-14 Creating Character Sets
39.12.4 Iterating Over Character Sets
-------------------------------------
Character set cursors are a means for iterating over the members of a
character sets. After creating a character set cursor with
`char-set-cursor', a cursor can be dereferenced with `char-set-ref',
advanced to the next member with `char-set-cursor-next'. Whether a
cursor has passed past the last element of the set can be checked with
`end-of-char-set?'.
Additionally, mapping and (un-)folding procedures for character sets
are provided.
-- 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_cs]
-- Scheme Procedure: char-set-unfold! p f g seed base_cs
This is a fundamental constructor for character sets.
* 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 the seed values.
* F maps each seed value to a character. These characters are
added to the base character set BASE_CS to form the result;
BASE_CS defaults to the empty set.
`char-set-unfold!' is the side-effecting variant.
-- Scheme Procedure: char-set-for-each proc cs
Apply PROC to every character in the character set CS. The return
value is not specified.
-- Scheme Procedure: char-set-map proc cs
Map the procedure PROC over every character in CS. PROC must be a
character -> character procedure.
Info Catalog
(guile.info.gz) SRFI-14 Predicates/Comparison
(guile.info.gz) SRFI-14
(guile.info.gz) SRFI-14 Creating Character Sets
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