(chibi string)

A cursor-oriented string library. Provides efficient string utilities for implementations with or without fast random-access strings.

High-level API

The procedures below are similar to those in SRFI 13 or other string libraries, except instead of receiving and returning character indexes they use opaque string cursors.

(string-null? str)

Returns true iff str is equal to the empty string "".

(->cursor str x)

(string-any check str . o)

Returns true iff check is true for any character in str. check can be a procedure, char (to test for char=? equivalence) or char-set (to test for char-set-contains?). Always returns false if str is empty.

(string-every check str . o)

Returns true iff check is true for every character in str. check can be a procedure, char or char-set as in string-any. Always returns true if str is empty.

(string-find str check [i])

Returns a cursor pointing to the first position from the left in string for which check is true. check can be a procedure, char or char-set as in string-any. The optional cursors start and end can specify a substring to search, and default to the whole string. Returns a cursor just past the end of str if no character matches.

(string-find? str check . o)

As above, ignoring the position and returning true iff any character matches.

(string-find-right str check . o)

As string-find, but returns the position of the first character from the right of str. If no character matches, returns a string cursor pointing just before start.

(string-skip str check . o)

As string-find, but inverts the check, returning the position of the first character which doesn't match.

(string-skip-right str check . o)

As string-find-right, but inverts the check, returning the position of the first character which doesn't match.

(string-join list-of-strings [separator])

Concatenates the list-of-strings and return the result as a single string. If separator is provided it is inserted between each pair of strings.

(string-split str [limit])

Split str into a list of substrings separated by pred, which defaults to #\space. Multiple adjacent characters which satisy pred will result in empty strings in the list. If the optional limit is provided, splits into at most that many substrings starting from the left.

(string-trim-left str . o)

Returns a copy of the string str with all characters matching pred (default #\space) removed from the left.

(string-trim-right str . o)

Returns a copy of the string str with all characters matching pred (default #\space) removed from the right.

(string-trim str [pred])

Returns a copy of the string str with all characters matching pred (default #\space) removed from both sides.

(string-mismatch prefix str)

Returns two values: the first cursors from the left in prefix and in str where the two strings don't match.

(string-mismatch-right suffix str)

Returns two values: the first cursors from the right in prefix and in str where the two strings don't match.

(string-prefix? prefix str)

Returns true iff prefix is a prefix of str.

(string-suffix? suffix str)

Returns true iff suffix is a suffix of str.

(string-fold kons knil str . los)

The fundamental string iterator. Calls kons on each character of str and an accumulator, starting with knil. If multiple strings are provided, calls kons on the corresponding characters of all strings, with the accumulator as the final argument, and terminates when the shortest string runs out.

(string-fold-right kons knil str)

Equivalent to string-fold, but iterates over str from right to left.

(string-map proc str)

Returns a new string composed of applying the procedure proc to every character in string.

(string-for-each proc str)

Apply proc to every character in str in order and discard the result.

(string-count str check)

Count the number of characters in str for which check is true.

(string-contains s1 s2 [start])

Returns a cursor pointing to the first position in the string s1 where s2 occurs, or #f if there is no such match.

(make-string-searcher needle)

Partial application of string-contains. Return a procedure of one argument, a string, which runs (string-contains str needle).

(string-downcase-ascii s)

Return a copy of string s with all 26 upper-case ASCII characters mapped to their corresponding 26 lower-case ASCII characters.

(string-upcase-ascii s)

Return a copy of string s with all 26 lower-case ASCII characters mapped to their corresponding 26 upper-case ASCII characters.

Cursor API

(substring-cursor str i [j])

Returns the substring of str between i (inclusive) and optional j (exclusive), which defaults to the end of the string.

(string-cursor-ref str i)

Returns the character of str at position i.

(string-cursor-start str)

Returns a string cursor pointing to the start of str.

(string-cursor-end str)

Returns a string cursor pointing just past the end of str.

(string-cursor-next str i)

Returns a string cursor to the character in str just after the cursor i.

(string-cursor-prev str i)

(string-cursor-forward str cursor n)

Returns a string cursor to the character in str just before the cursor i.

(string-cursor-back str cursor n)

(string-cursor<? i j)

(string-cursor>? i j)

(string-cursor=? i j)

(string-cursor<=? i j)

(string-cursor>=? i j)

String cursor comparators.