include "cowgol.coh";
include "strings.coh";

# Reverse a string in place
sub StrRev(s: [uint8]): (r: [uint8]) is
    r := s;
    var e := s;
    while [e] != 0 loop
        e := @next e;
    end loop;
    e := @prev e;
    while e > s loop
        var c := [s];
        [s] := [e];
        [e] := c;
        s := @next s;
        e := @prev e;
    end loop;
end sub;

# Test
var buf: uint8[32];
var str: [uint8] := "\nesreveR";
CopyString(str, &buf[0]);
print(StrRev(&buf[0]));