6.10.7 String utilities

Function: substring string start end

[R5RS]

Function: string-append string ...

[R5RS]

Function: string->list string &optional start end

Function: list->string list

[R5RS+][SRFI-13]

Function: string-copy string &optional start end

[R5RS+][SRFI-13]

Function: string-fill! string char &optional start end

[R5RS+][SRFI-13] Fills string by char. Optional start and end limits the effective area.

(string-fill! "orange" #\X) => "XXXXXX" (string-fill! "orange" #\X 2 4) => "orXXge"

Function: string-join strs &optional delim grammer

[SRFI-13] Concatenate strings in the list strs, with a string delim as `glue'.

The argument grammer may be one of the following symbol to specify how the strings are concatenated.

infix

Use delim between each string. This mode is default. Note that this mode introduce ambiguity when strs is an empty string or a list with a null string.

(string-join '("apple" "mango" "banana") ", ") => "apple, mango, banana" (string-join '() ":") => "" (string-join '("") ":") => ""

strict-infix

Works like infix, but empty list is not allowed to strs, thus avoiding ambiguity.

prefix

Use delim before each string.

(string-join '("usr" "local" "bin") "/" 'prefix) => "/usr/local/bin" (string-join '() "/" 'prefix) => "" (string-join '("") "/" 'prefix) => "/"

suffix

Use delim after each string.

(string-join '("a" "b" "c") "&" 'suffix) => "a&b&c&" (string-join '() "&" 'suffix) => "" (string-join '("") "&" 'suffix) => "&"

Function: string-scan string item &optional return

Scan item (either a string or a character) in string. The return argument specifies what value should be returned when item is found in string. It must be one of the following symbols.

index

Returns the index in string if item is found, or #f. This is the default behavior.

(string-scan "abracadabra" "ada") => 5 (string-scan "abracadabra" #\c) => 4 (string-scan "abracadabra" "aba") => #f

before

Returns a substring of string before item, or #f if item is not found.

(string-scan "abracadabra" "ada" 'before) => "abrac" (string-scan "abracadabra" #\c 'before) => "abra"

after

Returns a substring of string after item, or #f if item is not found.

(string-scan "abracadabra" "ada" 'after) => "bra" (string-scan "abracadabra" #\c 'after) => "adabra"

before*

Returns a substring of string before item, and the substring after it. If item is not found, returns (values #f #f).

(string-scan "abracadabra" "ada" 'before*) => "abrac" and "adabra" (string-scan "abracadabra" #\c 'before*) => "abra" and "cadabra"

after*

Returns a substring of string up to the end of item, and the rest. If item is not found, returns (values #f #f).

(string-scan "abracadabra" "ada" 'after*) => "abracada" and "bra" (string-scan "abracadabra" #\c 'after*) => "abrac" and "adabra"

both

Returns a substring of string before item and after item. If item is not found, returns (values #f #f).

(string-scan "abracadabra" "ada" 'both) => "abrac" and "bra" (string-scan "abracadabra" #\c 'both) => "abra" and "adabra"

Function: string-split s char