| 1 | import io |
| 2 | |
| 3 | struct Buf { |
| 4 | pub: |
| 5 | bytes []u8 |
| 6 | mut: |
| 7 | i int |
| 8 | } |
| 9 | |
| 10 | struct Writ { |
| 11 | pub mut: |
| 12 | bytes []u8 |
| 13 | } |
| 14 | |
| 15 | fn (mut b Buf) read(mut buf []u8) !int { |
| 16 | if !(b.i < b.bytes.len) { |
| 17 | return io.Eof{} |
| 18 | } |
| 19 | n := copy(mut buf, b.bytes[b.i..]) |
| 20 | b.i += n |
| 21 | return n |
| 22 | } |
| 23 | |
| 24 | fn (mut w Writ) write(buf []u8) !int { |
| 25 | if buf.len <= 0 { |
| 26 | return error('none') |
| 27 | } |
| 28 | w.bytes << buf |
| 29 | return buf.len |
| 30 | } |
| 31 | |
| 32 | fn test_copy() { |
| 33 | mut src := Buf{ |
| 34 | bytes: 'abcdefghij'.repeat(10).bytes() |
| 35 | } |
| 36 | mut dst := Writ{ |
| 37 | bytes: []u8{} |
| 38 | } |
| 39 | io.cp(mut src, mut dst) or { assert false } |
| 40 | assert dst.bytes == src.bytes |
| 41 | } |
| 42 | |