exc. 106 migrated

README.md

@@ -86,6 +86,8 @@ that if you update one, you may need to also update the other.
 
 ### Version Changes
 
+* *2026-01-xx* zig 0.16.0-dev.xx - file system I/O integrated with the std.Io interface, see [#30232](https://codeberg.org/ziglang/zig/pulls/30232)
+
 * *2025-11-01* zig 0.16.0-dev.1204 - more changes due to new I/O API, see [#25592](https://github.com/ziglang/zig/pull/25592)
 * *2025-09-24* zig 0.16.0-dev.377 - Enable passing file content as args, see [#25228](https://github.com/ziglang/zig/pull/25228)
 * *2025-09-03* zig 0.16.0-dev.164 - changes in reader, see [#25077](https://github.com/ziglang/zig/pull/25077)
@@ -233,7 +235,7 @@ Zig Core Language
 * [x] Sentinel termination
 * [x] Quoted identifiers @""
 * [x] Anonymous structs/tuples/lists
-* [ ] Async <--- ironically awaiting upstream Zig updates
+* [ ] Async I/O
 * [X] Interfaces
 * [X] Bit manipulation
 * [X] Working with C

exercises/106_files.zig

@@ -12,23 +12,27 @@
 // Fortunately, the Zig Standard Library provides a simple API for interacting
 // with the file system, see the detail documentation here:
 //
-// https://ziglang.org/documentation/master/std/#std.fs
+// https://ziglang.org/documentation/master/std/#std.Io
 //
 // In this exercise, we'll try to:
 //   - create a new directory,
 //   - open a file in the directory,
 //   - write to the file.
 //
-// import std as always
+// Note: For simplicity, we write byte-by-byte without buffering.
+// In real applications, you'd typically use a buffer for better
+// performance. We'll learn about buffered I/O in a later exercise.
+//
 const std = @import("std");
+const io = std.Options.debug_io;
 
 pub fn main() !void {
     // first we get the current working directory
-    const cwd: std.fs.Dir = std.fs.cwd();
+    const cwd: std.Io.Dir = std.Io.Dir.cwd();
 
     // then we'll try to make a new directory /output/
     // to store our output files.
-    cwd.makeDir("output") catch |e| switch (e) {
+    cwd.createDir(io, "output", .default_dir) catch |e| switch (e) {
         // there is a chance you might want to run this
         // program more than once and the path might already
         // have been created, so we'll have to handle this error
@@ -44,21 +48,24 @@ pub fn main() !void {
     // wait a minute...
     // opening a directory might fail!
     // what should we do here?
-    var output_dir: std.fs.Dir = cwd.openDir("output", .{});
-    defer output_dir.close();
+    var output_dir: std.Io.Dir = try cwd.openDir(io, "output", .{});
+    defer output_dir.close(io);
 
     // we try to open the file `zigling.txt`,
     // and propagate any error up
-    const file: std.fs.File = try output_dir.createFile("zigling.txt", .{});
+    const file: std.Io.File = try output_dir.createFile(io, "zigling.txt", .{});
     // it is a good habit to close a file after you are done with it
     // so that other programs can read it and prevent data corruption
     // but here we are not yet done writing to the file
     // if only there were a keyword in Zig that
     // allowed you to "defer" code execution to the end of the scope...
-    file.close();
+    file.close(io);
 
-    // you are not allowed to move these two lines above the file closing line!
-    const byte_written = try file.write("It's zigling time!");
+    // you are not allowed to move these lines above the file closing line!
+    var file_writer = file.writer(io, &.{});
+    const writer = &file_writer.interface;
+
+    const byte_written = try writer.write("It's zigling time!");
     std.debug.print("Successfully wrote {d} bytes.\n", .{byte_written});
 }
 // to check if you actually write to the file, you can either,
@@ -71,8 +78,8 @@ pub fn main() !void {
 // More on Creating files
 //
 // notice in:
-// ... try output_dir.createFile("zigling.txt", .{});
-//                                              ^^^
+// ... try output_dir.createFile(io, "zigling.txt", .{});
+//                                                  ^^^
 //                 we passed this anonymous struct to the function call
 //
 // this is the struct `CreateFlag` with default fields
@@ -87,7 +94,7 @@ pub fn main() !void {
 //
 // Question:
 //   - what should you do if you want to also read the file after opening it?
-//   - go to the documentation of the struct `std.fs.Dir` here:
+//   - go to the documentation of the struct `std.Io.Dir` here:
 //     https://ziglang.org/documentation/master/std/#std.fs.Dir
 //       - can you find a function for opening a file? how about deleting a file?
 //       - what kind of options can you use with those functions?

patches/patches/106_files.patch

@@ -1,6 +1,6 @@
---- exercises/106_files.zig	2025-08-24 19:23:55.168565003 +0200
-+++ answers/106_files.zig	2025-08-24 19:25:37.745597511 +0200
-@@ -35,7 +35,7 @@
+--- exercises/106_files.zig	2025-12-28 20:38:53.005504479 +0100
++++ answers/106_files.zig	2025-12-28 20:37:42.742154100 +0100
+@@ -39,7 +39,7 @@
          // by doing nothing
          //
          // we want to catch error.PathAlreadyExists and do nothing
@@ -9,21 +9,12 @@
          // if there's any other unexpected error we just propagate it through
          else => return e,
      };
-@@ -44,7 +44,7 @@
-     // wait a minute...
-     // opening a directory might fail!
-     // what should we do here?
--    var output_dir: std.fs.Dir = cwd.openDir("output", .{});
-+    var output_dir: std.fs.Dir = try cwd.openDir("output", .{});
-     defer output_dir.close();
- 
-     // we try to open the file `zigling.txt`,
-@@ -55,7 +55,7 @@
+@@ -59,7 +59,7 @@
      // but here we are not yet done writing to the file
      // if only there were a keyword in Zig that
      // allowed you to "defer" code execution to the end of the scope...
--    file.close();
-+    defer file.close();
+-    file.close(io);
++    defer file.close(io);
  
-     // you are not allowed to move these two lines above the file closing line!
-     const byte_written = try file.write("It's zigling time!");
+     // you are not allowed to move these lines above the file closing line!
+     var file_writer = file.writer(io, &.{});