generalized string conversion function.
get the string representation for the value of an object.
symbols like \".\" are converted to \"#{.}\" using display.

write converts symbols like \".\" to #{.}, this procedure avoids this

create a string of equally sized columns containing elements of the string list \"a\", separated
by #:separator

surround string with an open and a closing round bracket

checks if the string is enclosed by round brackets.
also checks if every opening bracket is paired with a closing one after it

replace strings inside string portions matched by regular expressions
the two part replacement element makes a simple replace,
the three part version replaces search-string only inside matches with replacement

replace all occurences of regexp in string with replacement

convert an ascii string that has incorrectly coded utf8 chars to an utf8 string

checks if every start-char in string has an end-char somewhere after it.
this can be used to check if there are missing round brackets in a string.
example: (string-brackets-closed? \"(ab (cd (e)) f)\" #\\( #\\))

replace multiple subsequent space characters with one space

result in a boolean indicating if string contains all of the patterns

result in a boolean indicating if string contains any of the patterns

remove prefix if string has prefix

remove suffix if string has suffix

append enclose-str to beginning and end of argument string

prepend character to the given string until the string length equals target-length.
examples
(string-fill-left \"1\" #\\0 2) -> \"01\"
(string-fill-left \"10\" #\\0 2) -> \"10\"
string-fill-left-zeros

result in a list of indices at which search-string occurs in a string

create a list of indices at which search-char occurs in a string

same as (string-join (flatten a) delimiter)

get the last possible index of a string

result in the element of prefix-list that is the longest prefix of prefix-list in string \"a\"

test if a string contains no uppercase characters

check if string is a valid scheme representation of a number

the number of bytes of string, regardless of the character encoding, without terminator like \"null\"

replace all occurences of \"char\" in a string

replace chars in string with none, one or multiple chars

replace all occurences of string \"replace\" inside string \"a\" with string \"replacement\".
tests have shown it to be up to 28x times faster than regexp-substitute/global (guile2.06 22x, guile3 5.75-28x).
this procedure is quite nice to debug - comment out one or all string-copy! calls and
the result string will be a partial result

skip over string \"skip\" at the beginning of a string and return the first index afterwards,
or the first index 0 if skip string is not a prefix

split line into slices/chunks of size slice-length, unless it would split words (subsequent characters without the space character),
in which case the word is moved to the next slice. ignores newlines. can be used for single lines. can be used for \"text-wrapping\".
splits string at spaces, then uses the parts to build lines while checking if the line length with spaces would exceed slice-length.
if yes, the exceeding part is moved to the next line

split string into a list of substrings delimited by a regular expression.
1. all regexp matches are collected
2. substrings between matches are extracted

remove all occurences of string \"trim\" from the beginning of a string.
like string-trim but with a trim-string instead of a character

converts \"a\" to string only if it is a symbol, otherwise results in \"a\"