Strings

A string can be mutable or immutable. When an immutable string is provided to a procedure like string-set!, the exn:application:type exception is raised.

String constants generated by read are immutable. (string->immutable-string string) returns an immutable string with the same content as string, returning string if it is already an immutable string.

When a string is created with make-string without a fill value, it is initialized with the null character (#\nul) in all positions.

The string comparison procedures -- string=?, string-ci=?, etc. -- take one or more string arguments and check the arguments pairwise (like the numerical comparison procedures).