string->list, list->string - convert between strings and lists

LIBRARY

(import (rnrs))                     ;R6RS
(import (rnrs base))                ;R6RS
(import (scheme r5rs))              ;R7RS
(import (scheme base))              ;R7RS

SYNOPSIS

(string->list string)
(string->list string start)         ;R7RS
(string->list string start end)     ;R7RS
(list->string list)

DESCRIPTION

The string->list procedure returns a newly allocated list of the characters that make up the given string.

The list->string procedure returns a newly allocated string formed from the characters in list.

These procedures are inverses so far as equal?(3string) is concerned, and preserve the order of the characters.

R7RS
The string->list procedure returns a newly allocated list of the characters of string between start (inclusive) and end (exclusive).

IMPLEMENTATION NOTES

Some implementations have a single empty string object; see make-string(3scm).

RETURN VALUES

Both of these procedures return a single value. The string->list procedure returns a list (a pair or the empty list); the list->string procedure returns a string object.

EXAMPLES

(string->list "Quux")  =>  (#\Q #\u #\u #\x)

(list->string '(#\f #\o #\o))  =>  "foo"

APPLICATION USAGE

These procedures can be seen in some highly functional programming styles.

COMPATIBILITY

The start and end arguments are unique to R7RS. The only other difference between implementations is whether the empty string is newly allocated or not (see above).

ERRORS

This procedure can raise exceptions with the following condition types:
&assertion (R6RS)
The wrong number of arguments was passed or an argument was outside its domain. In particular, list must be a list of characters and string must be a string.
R7RS
The assertions described above are errors. Implementations may signal an error, extend the procedure's domain of definition to include such arguments, or fail catastrophically.

SEE ALSO

list->vector(3scm), string-append(3scm)

STANDARDS

R4RS, R5RS, R6RS, R7RS

HISTORY

These procedures first appeared in R2RS. They are missing from IEEE Scheme.

AUTHORS

This page is part of the scheme-manpages project. It includes materials from the RnRS documents. More information can be found at https://github.com/schemedoc/manpages/.

Markup created by unroff 1.0sc,    March 04, 2023.