Integrate package io into core library

core/io/conv.odin

@@ -114,6 +114,21 @@ to_writer_to :: proc(s: Stream) -> (w: Writer_To, err: Conversion_Error) {
 	}
 	return;
 }
+to_Write_Closer :: proc(s: Stream) -> (w: Write_Closer, err: Conversion_Error) {
+	w.stream = s;
+	if s.stream_vtable == nil || s.impl_write == nil || s.impl_close == nil {
+		err = .Missing_Procedure;
+	}
+	return;
+}
+to_Write_Seeker :: proc(s: Stream) -> (w: Write_Seeker, err: Conversion_Error) {
+	w.stream = s;
+	if s.stream_vtable == nil || s.impl_write == nil || s.impl_seek == nil {
+		err = .Missing_Procedure;
+	}
+	return;
+}
+
 
 to_byte_reader :: proc(s: Stream) -> (b: Byte_Reader, err: Conversion_Error) {
 	b.stream = s;

core/io/io.odin

@@ -96,6 +96,9 @@ Read_Writer        :: struct {using stream: Stream};
 Read_Closer        :: struct {using stream: Stream};
 Read_Write_Closer  :: struct {using stream: Stream};
 Read_Write_Seeker  :: struct {using stream: Stream};
+
+Write_Closer       :: struct {using stream: Stream};
+Write_Seeker       :: struct {using stream: Stream};
 Write_Flusher      :: struct {using stream: Stream};
 Write_Flush_Closer :: struct {using stream: Stream};
 
@@ -117,7 +120,6 @@ destroy :: proc(s: Stream) -> Error {
 	if s.stream_vtable != nil && s.impl_destroy != nil {
 		return s->impl_destroy();
 	}
-	// Instead of .Empty, .None is fine in this case
 	return close_err;
 }
 
@@ -205,9 +207,14 @@ read_at :: proc(r: Reader_At, p: []byte, offset: i64) -> (n: int, err: Error) {
 	if err != nil {
 		return 0, err;
 	}
-	defer r->impl_seek(current_offset, .Start);
 
-	return r->impl_read(p);
+	n, err = r->impl_read(p);
+	if err != nil {
+		return;
+	}
+	_, err = r->impl_seek(current_offset, .Start);
+	return;
+
 }
 
 write_at :: proc(w: Writer_At, p: []byte, offset: i64) -> (n: int, err: Error) {

core/io/util.odin

@@ -14,6 +14,13 @@ write_i64 :: proc(w: Writer, i: i64, base: int = 10) -> (n: int, err: Error) {
 	return write_string(w, s);
 }
 
+write_uint :: proc(w: Writer, i: uint, base: int = 10) -> (n: int, err: Error) {
+	return write_u64(w, u64(i), base);
+}
+write_int :: proc(w: Writer, i: int, base: int = 10) -> (n: int, err: Error) {
+	return write_i64(w, i64(i), base);
+}
+
 @(private)
 Tee_Reader :: struct {
 	using stream: Stream,