hare

commit 1c1287bd183027172b7d7ccebd5cb5c55c4309b6
parent 62eee8d4f453be39abe95e6a59232d7930923012
Author: Drew DeVault <sir@cmpwn.com>
Date:   Fri, 26 Feb 2021 12:28:40 -0500

endian: new module (WIP)

Diffstat:
A
endian/big.ha
 | 
31
+++++++++++++++++++++++++++++++

1 file changed, 31 insertions(+), 0 deletions(-)
diff --git a/endian/big.ha b/endian/big.ha
@@ -0,0 +1,31 @@
+// Writes a u32 into a buffer in big-endian order.
+export fn beputu32(buf: []u8, in: u32) void = {
+	buf[3] = (in): u8;
+	buf[2] = (in >> 8): u8;
+	buf[1] = (in >> 16): u8;
+	buf[0] = (in >> 24): u8;
+};
+
+// Writes a u64 into a buffer in big-endian order.
+export fn beputu64(buf: []u8, in: u64) void = {
+	buf[7] = (in >> 0): u8;
+	buf[6] = (in >> 8): u8;
+	buf[5] = (in >> 16): u8;
+	buf[4] = (in >> 24): u8;
+	buf[3] = (in >> 32): u8;
+	buf[2] = (in >> 40): u8;
+	buf[1] = (in >> 48): u8;
+	buf[0] = (in >> 56): u8;
+};
+
+@test fn big() void = {
+	let buf: [8]u8 = [0...];
+	beputu32(buf, 0x12345678);
+	assert(buf[0] == 0x12 && buf[1] == 0x34
+		&& buf[2] == 0x56 && buf[3] == 0x78);
+	beputu64(buf, 0x1234567887654321);
+	assert(buf[0] == 0x12 && buf[1] == 0x34
+		&& buf[2] == 0x56 && buf[3] == 0x78
+		&& buf[4] == 0x87 && buf[5] == 0x65
+		&& buf[6] == 0x43 && buf[7] == 0x21);
+};