Merge pull request 'I/O improvements' (#355) from io_improvements into main

Reviewed-on: https://codeberg.org/ziglings/exercises/pulls/355

exercises/026_hello2.zig

@@ -5,9 +5,6 @@
 //
 const std = @import("std");
 
-// Instance for input/output operations; we will learn more about this later.
-const io = std.Options.debug_io;
-
 // Take note that this main() definition now returns "!void" rather
 // than just "void". Since there's no specific error type, this means
 // that Zig will infer the error type. This is appropriate in the case
@@ -17,7 +14,10 @@ const io = std.Options.debug_io;
 // You can find more information at:
 // https://ziglang.org/documentation/master/#Inferred-Error-Sets
 //
-pub fn main() !void {
+pub fn main(init: std.process.Init) !void {
+    // Instance for input/output operations; we will learn more about this later.
+    const io = init.io;
+
     // We get a Writer for Standard Out...
     var stdout_writer = std.Io.File.stdout().writer(io, &.{});
     // ...and extract its interface so we can print() to it.

exercises/034_quiz4.zig

@@ -6,11 +6,11 @@
 //     my_num=42
 //
 const std = @import("std");
-const io = std.Options.debug_io;
 
 const NumError = error{IllegalNumber};
 
-pub fn main() void {
+pub fn main(init: std.process.Init) !void {
+    const io = init.io;
     var stdout_writer = std.Io.File.stdout().writer(io, &.{});
     const stdout = &stdout_writer.interface;
 

exercises/106_files.zig

@@ -24,9 +24,11 @@
 // 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 {
+pub fn main(init: std.process.Init) !void {
+    // default I/O implementation
+    const io = init.io;
+
     // first we get the current working directory
     const cwd: std.Io.Dir = std.Io.Dir.cwd();
 

exercises/107_files2.zig

@@ -21,9 +21,10 @@
 // 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 {
+pub fn main(init: std.process.Init) !void {
+    const io = init.io;
+
     // Get the current working directory
     const cwd = std.Io.Dir.cwd();
 

patches/patches/026_hello2.patch

@@ -1,5 +1,5 @@
---- exercises/026_hello2.zig	2025-12-30 13:39:29.478620712 +0100
+--- exercises/026_hello2.zig	2026-01-09 22:51:45.803358789 +0100
-+++ answers/026_hello2.zig	2025-12-30 13:39:18.948412943 +0100
++++ answers/026_hello2.zig	2026-01-09 22:50:46.016166527 +0100
 @@ -28,5 +28,5 @@
      // to be able to pass it up as a return value of main().
      //

patches/patches/034_quiz4.patch

@@ -1,11 +1,6 @@
---- exercises/034_quiz4.zig	2025-12-28 14:43:41.087943476 +0100
+--- exercises/034_quiz4.zig	2026-01-09 22:45:53.115325559 +0100
-+++ answers/034_quiz4.zig	2025-12-28 14:42:23.878472164 +0100
++++ answers/034_quiz4.zig	2026-01-09 22:45:15.658578603 +0100
-@@ -10,11 +10,11 @@
+@@ -14,7 +14,7 @@
- 
- const NumError = error{IllegalNumber};
- 
--pub fn main() void {
-+pub fn main() !void {
      var stdout_writer = std.Io.File.stdout().writer(io, &.{});
      const stdout = &stdout_writer.interface;
  

patches/patches/106_files.patch

@@ -1,6 +1,6 @@
---- exercises/106_files.zig	2025-12-28 20:38:53.005504479 +0100
+--- exercises/106_files.zig	2026-01-09 22:41:19.373872684 +0100
-+++ answers/106_files.zig	2025-12-28 20:37:42.742154100 +0100
++++ answers/106_files.zig	2026-01-09 22:41:44.518372910 +0100
-@@ -39,7 +39,7 @@
+@@ -41,7 +41,7 @@
          // by doing nothing
          //
          // we want to catch error.PathAlreadyExists and do nothing
@@ -9,7 +9,7 @@
          // if there's any other unexpected error we just propagate it through
          else => return e,
      };
-@@ -59,7 +59,7 @@
+@@ -61,7 +61,7 @@
      // 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...

patches/patches/107_files2.patch

@@ -1,6 +1,6 @@
---- exercises/107_files2.zig	2025-12-28 21:17:29.658147954 +0100
+--- exercises/107_files2.zig	2026-01-09 22:43:15.211177186 +0100
-+++ answers/107_files2.zig	2025-12-28 21:17:10.585787203 +0100
++++ answers/107_files2.zig	2026-01-09 22:42:48.943654602 +0100
-@@ -38,7 +38,7 @@
+@@ -39,7 +39,7 @@
      // initialize an array of u8 with all letter 'A'
      // we need to pick the size of the array, 64 seems like a good number
      // fix the initialization below
@@ -9,7 +9,7 @@
      // this should print out : `AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA`
      std.debug.print("{s}\n", .{content});
  
-@@ -49,12 +49,12 @@
+@@ -50,12 +50,12 @@
      // can you go here to find a way to read the content?
      // https://ziglang.org/documentation/master/std/#std.Io.Reader
      // hint: look for a method that reads into a slice