SCM_API SCM scm_string_replace (SCM s1, SCM s2, SCM start1, SCM end1, SCM start2, SCM end2);
SCM_API SCM scm_string_tokenize (SCM s, SCM token_char, SCM start, SCM end);
SCM_API SCM scm_string_split (SCM s, SCM chr);
SCM_API SCM scm_string_replace (SCM s1, SCM s2, SCM start1, SCM end1, SCM start2, SCM end2);
SCM_API SCM scm_string_tokenize (SCM s, SCM token_char, SCM start, SCM end);
SCM_API SCM scm_string_split (SCM s, SCM chr);