2 files changed, 19 insertions(+), 25 deletions(-)

M README.md
M src/netstring.zig

@@ 21,9 21,8 @@ pub fn main() !void {
     var parser = netstring.netStringParser(input.reader());
 
     // Repeat while the parser can find another netstring
-    while (try parser.next()) {
+    while (try parser.next()) |reader| {
         // Read the current netstring and print it
-        const reader = parser.reader();
         const msg = try reader.readAllAlloc(std.heap.page_allocator, 4096);
         std.debug.print("{s}\n", .{msg});
     }

@@ 14,9 14,8 @@ pub fn NetStringParser(comptime ReaderType: type) type {
         const Error = ReaderType.Error;
         const Reader = std.io.Reader(*@This(), Error, read);
 
-        /// Aligns reader at beginning of next netstring. Returns true if
-        /// another netstring was found, false if not.
-        pub fn next(self: *@This()) !bool {
+        /// Moves input to beginning of next netstring and returns a Reader for it.
+        pub fn next(self: *@This()) !?Reader {
             var r = self.child_reader.reader();
             // move stream to end of current netstring
             if (self.child_reader.bytes_read < self.end) {


@@ 27,16 26,16 @@ pub fn NetStringParser(comptime ReaderType: type) type {
             if (size_str) |s| {
                 const size = try std.fmt.parseUnsigned(usize, s, 10);
                 self.end = self.child_reader.bytes_read + size + 1;
-                return true;
+                return self.reader();
             } else {
-                return false;
+                return null;
             }
         }
 
         /// Reads bytes from the current netstring returning number of bytes read.
         /// If the number of bytes read is 0 it means the stream reached the end
         /// of the current netstring.
-        pub fn read(self: *@This(), buf: []u8) Error!usize {
+        fn read(self: *@This(), buf: []u8) Error!usize {
             // read until one byte before end because of tailing comma
             if (self.child_reader.bytes_read + 1 >= self.end) {
                 return 0;


@@ 51,7 50,7 @@ pub fn NetStringParser(comptime ReaderType: type) type {
         /// Returns a std.io.Reader for the current netstring. Calling `next()`
         /// on this parser will move the reader onto the next netstring. This
         /// must be done before the first netstring can be read.
-        pub fn reader(self: *@This()) Reader {
+        fn reader(self: *@This()) Reader {
             return .{ .context = self };
         }
     };


@@ 66,77 65,73 @@ test "parse empty input stream" {
     var p = netStringParser(input.reader());
     var msg: [1024]u8 = undefined;
     try testing.expectEqual(@intCast(usize, 0), try p.reader().read(&msg));
-    try testing.expectEqual(false, try p.next());
+    try testing.expectEqual(try p.next(), null);
 }
 
 test "parse single netstring" {
     var input = std.io.fixedBufferStream("5:hello,");
     var p = netStringParser(input.reader());
     var msg: [1024]u8 = undefined;
-    const r = p.reader();
-    try testing.expectEqual(true, try p.next());
+    const r = (try p.next()).?;
     const bytes = try r.read(&msg);
     try testing.expectEqual(@intCast(usize, 5), bytes);
     try testing.expectEqualSlices(u8, "hello", msg[0..bytes]);
     try testing.expectEqual(@intCast(usize, 0), try r.read(&msg));
-    try testing.expectEqual(false, try p.next());
+    try testing.expectEqual(try p.next(), null);
 }
 
 test "parse multiple netstrings" {
     var input = std.io.fixedBufferStream("5:hello,1:,,7: world!,");
     var p = netStringParser(input.reader());
     var msg: [1024]u8 = undefined;
-    const r = p.reader();
-    try testing.expectEqual(true, try p.next());
     {
+        const r = (try p.next()).?;
         const bytes = try r.read(&msg);
         try testing.expectEqual(@intCast(usize, 5), bytes);
         try testing.expectEqualSlices(u8, "hello", msg[0..bytes]);
         try testing.expectEqual(@intCast(usize, 0), try r.read(&msg));
     }
-    try testing.expectEqual(true, try p.next());
     {
+        const r = (try p.next()).?;
         const bytes = try r.read(&msg);
         try testing.expectEqual(@intCast(usize, 1), bytes);
         try testing.expectEqualSlices(u8, ",", msg[0..bytes]);
         try testing.expectEqual(@intCast(usize, 0), try r.read(&msg));
     }
-    try testing.expectEqual(true, try p.next());
     {
+        const r = (try p.next()).?;
         const bytes = try r.read(&msg);
         try testing.expectEqual(@intCast(usize, 7), bytes);
         try testing.expectEqualSlices(u8, " world!", msg[0..bytes]);
         try testing.expectEqual(@intCast(usize, 0), try r.read(&msg));
     }
-    try testing.expectEqual(false, try p.next());
+    try testing.expectEqual(try p.next(), null);
 }
 
 test "calling next before completely reading current netstring" {
     var input = std.io.fixedBufferStream("3:foo,3:bar,");
     var p = netStringParser(input.reader());
     var msg: [1]u8 = undefined;
-    const r = p.reader();
-    try testing.expectEqual(true, try p.next());
     {
+        const r = (try p.next()).?;
         const bytes = try r.read(&msg);
         try testing.expectEqual(@intCast(usize, 1), bytes);
         try testing.expectEqualSlices(u8, "f", msg[0..bytes]);
     }
-    try testing.expectEqual(true, try p.next());
     {
+        const r = (try p.next()).?;
         const bytes = try r.read(&msg);
         try testing.expectEqual(@intCast(usize, 1), bytes);
         try testing.expectEqualSlices(u8, "b", msg[0..bytes]);
+        // attempt to keep reading past current netstring
+        try testing.expectEqual(try p.next(), null);
+        try testing.expectEqual(@intCast(usize, 0), try r.read(&msg));
     }
-    try testing.expectEqual(false, try p.next());
-    try testing.expectEqual(@intCast(usize, 0), try r.read(&msg));
 }
 
 test "invalid input" {
     var input = std.io.fixedBufferStream("hello");
     var p = netStringParser(input.reader());
     var msg: [1024]u8 = undefined;
-    const r = p.reader();
     try testing.expectError(error.InvalidCharacter, p.next());
-    try testing.expectEqual(@intCast(usize, 0), try r.read(&msg));
 }