Moved over code from Vieter

util/util.v

@@ -0,0 +1,65 @@
+module util
+
+import io
+
+// reader_to_writer tries to consume the entire reader & write it to the writer.
+pub fn reader_to_writer(mut reader io.Reader, mut writer io.Writer) ? {
+	mut buf := []u8{len: 10 * 1024}
+
+	for {
+		bytes_read := reader.read(mut buf) or { break }
+		mut bytes_written := 0
+
+		for bytes_written < bytes_read {
+			c := writer.write(buf[bytes_written..bytes_read]) or { break }
+
+			bytes_written += c
+		}
+	}
+}
+
+// match_array_in_array<T> returns how many elements of a2 overlap with a1. For
+// example, if a1 = "abcd" & a2 = "cd", the result will be 2. If the match is
+// not at the end of a1, the result is 0.
+pub fn match_array_in_array<T>(a1 []T, a2 []T) int {
+	mut i := 0
+	mut match_len := 0
+
+	for i + match_len < a1.len {
+		if a1[i + match_len] == a2[match_len] {
+			match_len += 1
+		} else {
+			i += match_len + 1
+			match_len = 0
+		}
+	}
+
+	return match_len
+}
+
+// read_until_separator consumes an io.Reader until it encounters some
+// separator array. The data read is stored inside the provided res array.
+pub fn read_until_separator(mut reader io.Reader, mut res []u8, sep []u8) ? {
+	mut buf := []u8{len: sep.len}
+
+	for {
+		c := reader.read(mut buf)?
+		res << buf[..c]
+
+		match_len := match_array_in_array(buf[..c], sep)
+
+		if match_len == sep.len {
+			break
+		}
+
+		if match_len > 0 {
+			match_left := sep.len - match_len
+			c2 := reader.read(mut buf[..match_left])?
+			res << buf[..c2]
+
+			if buf[..c2] == sep[match_len..] {
+				break
+			}
+		}
+	}
+}