In Guile 1.6.*, the function scm_istring2number(char *str,int strlen,int radix) does the work.
However, this function does not exist in Guile 1.8.. How can I accomplish the same task in Guile 1.8.?
This is not trivial because the function scm_string_to_number(SCM str,int radix) does not convert numbers larger than 231-1 (at least in Guile 1.6.*).
According to the 1.8 ChangeLog, the function has been renamed
scm_c_locale_stringn_to_number.