hare

commit 4f5aa8ca2f055c3871f94997de1267491c572811
parent bf44ee8f689a7c04516daf77bb590c20a7f5a14b
Author: Drew DeVault <sir@cmpwn.com>
Date:   Mon,  1 Feb 2021 12:59:12 -0500

io: add io::copy

Diffstat:
A
io/copy.ha
 | 
23
+++++++++++++++++++++++

1 file changed, 23 insertions(+), 0 deletions(-)
diff --git a/io/copy.ha b/io/copy.ha
@@ -0,0 +1,23 @@
+// Copies data from one stream into another. Note that this function will never
+// return if the source stream is infinite.
+export fn copy(dest: *stream, src: *stream) (error | size) = {
+	let w = 0z;
+	let buf: [4096]u8 = [0u8...];
+	for (true) {
+		match (read(src, buf[..])) {
+			err: error => match (err) {
+				closed => break,
+				* => return err,
+			},
+			n: size => {
+				match (write(dest, buf[..n])) {
+					err: error => return err,
+					size => {
+						w += n;
+					},
+				};
+			},
+		};
+	};
+	return w;
+};