2.8.2.5 R4RS/R5RS procedures

The R4RS and R5RS reports define 22 string procedures. The SRFI-13 package includes 8 of these exactly as defined, 3 in an extended, backwards–compatible way, and drops the remaining 11 (whose functionality is available via other bindings).

The 8 procedures provided exactly as documented in the reports are:

string?         make-string     string
string-length   string-ref      string-set!
string-append   list->string

The 11 functions not included are:

string=?        string-ci=?     string<?
string-ci<?     string>?        string-ci>?
string<=?       string-ci<=?    string>=?
string-ci>=?    substring

the SRFI-13 package provides alternate bindings and extended functionality.

Additionally, the three extended procedures are:

string-fill! s char [start end] -> unspecified
string->list s [start end] -> char-list
string-copy  s [start end] -> string

they are uniformly extended to take optional start/end parameters specifying substring ranges.