libuv: start shared stream functions

src/libuv/Tty.zig

@@ -9,11 +9,13 @@ const c = @import("c.zig");
 const errors = @import("error.zig");
 const Loop = @import("Loop.zig");
 const Handle = @import("handle.zig").Handle;
+const Stream = @import("stream.zig").Stream;
 const Pty = @import("../Pty.zig");
 
 handle: *c.uv_tty_t,
 
 pub usingnamespace Handle(Tty);
+pub usingnamespace Stream(Tty);
 
 pub fn init(alloc: Allocator, loop: Loop, fd: fd_t) !Tty {
     var tty = try alloc.create(c.uv_tty_t);
@@ -41,6 +43,9 @@ test "Tty" {
     var tty = try init(testing.allocator, loop, pty.slave);
     defer tty.deinit(testing.allocator);
 
+    try testing.expect(try tty.isReadable());
+    try testing.expect(try tty.isWritable());
+
     tty.close(null);
     _ = try loop.run(.default);
 }

src/libuv/stream.zig

@@ -0,0 +1,33 @@
+const c = @import("c.zig");
+
+const Loop = @import("Loop.zig");
+const errors = @import("error.zig");
+
+/// Returns a struct that has all the shared stream functions for the
+/// given stream type T. The type T must have a field named "handle".
+/// This is expected to be used with usingnamespace to add the shared
+/// stream functions to other handle types.
+pub fn Stream(comptime T: type) type {
+    // 1. T should be a struct
+    // 2. First field should be the handle pointer
+
+    return struct {
+        // note: this has to be here: https://github.com/ziglang/zig/issues/11367
+        const tInfo = @typeInfo(T).Struct;
+        const HandleType = tInfo.fields[0].field_type;
+
+        /// Returns 1 if the stream is readable, 0 otherwise.
+        pub fn isReadable(self: T) !bool {
+            const res = c.uv_is_readable(@ptrCast(*c.uv_stream_t, self.handle));
+            try errors.convertError(res);
+            return res > 0;
+        }
+
+        /// Returns 1 if the stream is writable, 0 otherwise.
+        pub fn isWritable(self: T) !bool {
+            const res = c.uv_is_writable(@ptrCast(*c.uv_stream_t, self.handle));
+            try errors.convertError(res);
+            return res > 0;
+        }
+    };
+}