String Handling

The following Scheme functions can be used for strings:

(string-append s1 s2...)

Append the string arguments and return the resulting string.

(substring str start end)

Returns the part of str between start and end.

(string-search token str)

Returns the index of token in str.

(string-trim str)

Removes whitespace from both ends of str.

(string-trim-left str)

Removes whitespace from the beginning of str.

(string-trim-right str)

Removes whitespace from the end of str.

(string-upcase str)

Converts all characters in str to upper case.

(string-downcase str)

Converts all characters in str to lower case.