From 924780d92c148c8a76936d17599e64ab9d204860 Mon Sep 17 00:00:00 2001
From: kayomn <kayomn@kayomn.net>
Date: Mon, 20 Feb 2023 00:34:46 +0000
Subject: [PATCH] Update coral library to use new reader / writer system

---
 source/coral.cpp | 40 +++++++++++++++++++++-------------------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/source/coral.cpp b/source/coral.cpp
index 4d265c4..6e2826f 100644
--- a/source/coral.cpp
+++ b/source/coral.cpp
@@ -450,9 +450,13 @@ export namespace coral {
 		unavailable,
 	};
 
-	using readable = callable<expected<usize, io_error>(slice<u8> const &)>;
+	struct reader {
+		virtual expected<usize, io_error> read(slice<u8> const & buffer) = 0;
+	};
 
-	using writable = callable<expected<usize, io_error>(slice<u8 const> const &)>;
+	struct writer {
+		virtual expected<usize, io_error> write(slice<u8 const> const & buffer) = 0;
+	};
 }
 
 // Input/output operations.
@@ -533,30 +537,28 @@ export namespace coral {
 	 * *Note*: if `buffer` has a length of `0`, no data will be streamed as there is nowhere to
 	 * temporarily place data during streaming.
 	 */
-	expected<usize, io_error> stream(writable const & output,
-		readable const & input, slice<u8> const & buffer) {
+	expected<usize, io_error> stream(writer & output, reader & input, slice<u8> const & buffer) {
+		usize total_bytes_written = 0;
+		expected bytes_read = input.read(buffer);
 
-		usize written = 0;
-		expected maybe_read = input(buffer);
+		if (!bytes_read.is_ok()) return bytes_read.error();
 
-		if (!maybe_read.is_ok()) return maybe_read.error();
-
-		usize read = maybe_read.value();
+		usize read = bytes_read.value();
 
 		while (read != 0) {
-			expected const maybe_written = output(buffer.sliced(0, read));
+			expected const bytes_written = output.write(buffer.sliced(0, read));
 
-			if (!maybe_written.is_ok()) return maybe_read.error();
+			if (!bytes_written.is_ok()) return bytes_read.error();
 
-			written += maybe_written.value();
-			maybe_read = input(buffer);
+			total_bytes_written += bytes_written.value();
+			bytes_read = input.read(buffer);
 
-			if (!maybe_read.is_ok()) return maybe_read.error();
+			if (!bytes_read.is_ok()) return bytes_read.error();
 
-			read = maybe_read.value();
+			read = bytes_read.value();
 		}
 
-		return written;
+		return total_bytes_written;
 	}
 
 	/**
@@ -565,8 +567,8 @@ export namespace coral {
 	 * The returned [expected] can be used to introspect if `output` encountered any issues during
 	 * printing, otherwise it will contain the number of characters used to print `value` as text.
 	 */
-	expected<usize, io_error> print_unsigned(writable const & output, u64 value) {
-		if (value == 0) return output(slice{"0"}.as_bytes());
+	expected<usize, io_error> print_unsigned(writer & output, u64 value) {
+		if (value == 0) return output.write(slice{"0"}.as_bytes());
 
 		u8 buffer[20]{0};
 		usize buffer_count{0};
@@ -584,7 +586,7 @@ export namespace coral {
 		for (usize i = 0; i < half_buffer_count; i += 1)
 			swap(buffer[i], buffer[buffer_count - i - 1]);
 
-		return output(slice{buffer, buffer_count});
+		return output.write(slice{buffer, buffer_count});
 	}
 
 	/**