Insert space for additional async exercises

build.zig

@@ -1153,17 +1153,29 @@ const exercises = [_]Exercise{
     },
     .{
         .main_file = "090_async7.zig",
-        .output = "Counter: 400 (expected: 400)",
+        .output = "Counter: 400",
     },
     .{
         .main_file = "091_async8.zig",
-        .output = "ABCDEF",
+        .output = "Sum of 1..10 = 55",
-        .skip = true,
-        .skip_hint = "async has not been implemented in the current compiler version.",
     },
-
     .{
-        .main_file = "092_interfaces.zig",
+        .main_file = "092_async9.zig",
+        .output = "",
+        .skip = true,
+    },
+    .{
+        .main_file = "093_async10.zig",
+        .output = "",
+        .skip = true,
+    },
+    .{
+        .main_file = "094_async_quiz.zig",
+        .output = "",
+        .skip = true,
+    },
+    .{
+        .main_file = "095_interfaces.zig",
         .output =
         \\Daily Insect Report:
         \\Ant is alive.
@@ -1172,33 +1184,33 @@ const exercises = [_]Exercise{
         , // pay attention to the comma
     },
     .{
-        .main_file = "093_hello_c.zig",
+        .main_file = "096_hello_c.zig",
         .output = "Hello C from Zig! - C result is 17 chars written.",
         .link_libc = true,
     },
     .{
-        .main_file = "094_c_math.zig",
+        .main_file = "097_c_math.zig",
         .output = "The normalized angle of 765.2 degrees is 45.2 degrees.",
         .link_libc = true,
     },
     .{
-        .main_file = "095_for3.zig",
+        .main_file = "098_for3.zig",
         .output = "1 2 4 7 8 11 13 14 16 17 19\n1 2 3 4 5 6 7 8 9 10 11 12 13 14 15",
     },
     .{
-        .main_file = "096_memory_allocation.zig",
+        .main_file = "099_memory_allocation.zig",
         .output = "Running Average: 0.30 0.25 0.20 0.18 0.22",
     },
     .{
-        .main_file = "097_bit_manipulation.zig",
+        .main_file = "100_bit_manipulation.zig",
         .output = "x = 1011; y = 1101",
     },
     .{
-        .main_file = "098_bit_manipulation2.zig",
+        .main_file = "101_bit_manipulation2.zig",
         .output = "Is this a pangram? true!",
     },
     .{
-        .main_file = "099_formatting.zig",
+        .main_file = "102_formatting.zig",
         .output =
         \\
         \\ X |  1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
@@ -1235,11 +1247,11 @@ const exercises = [_]Exercise{
         ,
     },
     .{
-        .main_file = "100_for4.zig",
+        .main_file = "103_for4.zig",
         .output = "Arrays match!",
     },
     .{
-        .main_file = "101_for5.zig",
+        .main_file = "104_for5.zig",
         .output =
         \\1. Wizard (Gold: 25, XP: 40)
         \\2. Bard (Gold: 11, XP: 17)
@@ -1248,12 +1260,12 @@ const exercises = [_]Exercise{
         , // pay attention to the comma
     },
     .{
-        .main_file = "102_testing.zig",
+        .main_file = "105_testing.zig",
         .output = "",
         .kind = .@"test",
     },
     .{
-        .main_file = "103_tokenization.zig",
+        .main_file = "106_tokenization.zig",
         .output =
         \\My
         \\name
@@ -1274,7 +1286,7 @@ const exercises = [_]Exercise{
         , // pay attention to the comma
     },
     .{
-        .main_file = "104_threading.zig",
+        .main_file = "107_threading.zig",
         .output =
         \\Starting work...
         \\thread 1: started.
@@ -1288,32 +1300,32 @@ const exercises = [_]Exercise{
         , // pay attention to the comma
     },
     .{
-        .main_file = "105_threading2.zig",
+        .main_file = "108_threading2.zig",
         .output = "PI ≈ 3.14159265",
     },
     .{
-        .main_file = "106_files.zig",
+        .main_file = "109_files.zig",
         .output = "Successfully wrote 18 bytes.",
     },
     .{
-        .main_file = "107_files2.zig",
+        .main_file = "110_files2.zig",
         .output =
         \\AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
         \\Successfully Read 18 bytes: It's zigling time!
         , // pay attention to the comma
     },
     .{
-        .main_file = "108_labeled_switch.zig",
+        .main_file = "111_labeled_switch.zig",
         .output = "The pull request has been merged.",
     },
     .{
-        .main_file = "109_vectors.zig",
+        .main_file = "112_vectors.zig",
         .output =
         \\Max difference (old fn): 0.014
         \\Max difference (new fn): 0.014
         , // pay attention to the comma
     },
-    .{ .main_file = "110_quiz9.zig", .output =
+    .{ .main_file = "113_quiz9.zig", .output =
     \\Toggle pins with XOR on PORTB
     \\-----------------------------
     \\  1100 // (initial state of PORTB)
@@ -1345,11 +1357,11 @@ const exercises = [_]Exercise{
     \\= 0110
     },
     .{
-        .main_file = "111_packed.zig",
+        .main_file = "114_packed.zig",
         .output = "",
     },
     .{
-        .main_file = "112_packed2.zig",
+        .main_file = "115_packed2.zig",
         .output = "",
     },
     .{

exercises/090_async7.zig

@@ -42,7 +42,7 @@ pub fn main(init: std.process.Init) !void {
 
     try group.await(io);
 
-    print("Counter: {} (expected: 400)\n", .{state.counter});
+    print("Counter: {}\n", .{state.counter});
 }
 
 fn increment(io: std.Io, state: *SharedState, times: u32) void {

exercises/091_async8.zig

@@ -1,35 +1,62 @@
 //
-// You have doubtless noticed that 'suspend' requires a block
+// Tasks often need to communicate! Io provides Queue for this —
-// expression like so:
+// a bounded, thread-safe channel for passing data between tasks:
 //
-//     suspend {}
+//     var backing: [16]u32 = undefined;
+//     var queue: std.Io.Queue(u32) = .init(&backing);
 //
-// The suspend block executes when a function suspends. To get
+//     // Producer task:
-// sense for when this happens, please make the following
+//     try queue.putOne(io, value);    // blocks if queue is full
-// program print the string
 //
-//     "ABCDEF"
+//     // Consumer task:
+//     const val = try queue.getOne(io);  // blocks if queue is empty
 //
-const print = @import("std").debug.print;
+// When the producer is done, it calls queue.close(io) to signal
+// that no more data is coming. After that, getOne() will return
+// error.Closed once the queue is drained.
+//
+// This is the classic producer/consumer pattern — one task
+// generates work, another processes it, and the queue handles
+// all the synchronization automatically.
+//
+// Fix this program: the producer sends numbers 1..10, the
+// consumer sums them up. The expected sum is 55.
+//
+const std = @import("std");
+const print = std.debug.print;
 
-pub fn main() void {
+pub fn main(init: std.process.Init) !void {
-    print("A", .{});
+    const io = init.io;
 
-    var frame = async suspendable();
+    var backing: [4]u32 = undefined;
+    var queue: std.Io.Queue(u32) = .init(&backing);
 
-    print("X", .{});
+    var group: std.Io.Group = .init;
 
-    resume frame;
+    group.async(io, producer, .{ io, &queue });
+    group.async(io, consumer, .{ io, &queue });
 
-    print("F", .{});
+    try group.await(io);
 }
 
-fn suspendable() void {
+fn producer(io: std.Io, queue: *std.Io.Queue(u32)) void {
-    print("X", .{});
+    // Send numbers 1 through 10 into the queue.
-
+    for (1..11) |i| {
-    suspend {
+        // What Queue method sends a single element, blocking if full?
-        print("X", .{});
+        queue.???(io, @intCast(i)) catch return;
     }
-
+    // Signal that we're done sending.
-    print("X", .{});
+    queue.close(io);
+}
+
+fn consumer(io: std.Io, queue: *std.Io.Queue(u32)) void {
+    var sum: u32 = 0;
+    while (true) {
+        const value = queue.getOne(io) catch |err| switch (err) {
+            error.Closed => break,
+            error.Canceled => return,
+        };
+        sum += value;
+    }
+    print("Sum of 1..10 = {}\n", .{sum});
 }

patches/patches/091_async8.patch

@@ -0,0 +1,11 @@
+--- exercises/091_async8.zig	2026-04-02 10:49:27.925721496 +0200
++++ answers/091_async8.zig	2026-04-02 10:49:31.694795212 +0200
+@@ -43,7 +43,7 @@
+     // Send numbers 1 through 10 into the queue.
+     for (1..11) |i| {
+         // What Queue method sends a single element, blocking if full?
+-        queue.???(io, @intCast(i)) catch return;
++        queue.putOne(io, @intCast(i)) catch return;
+     }
+     // Signal that we're done sending.
+     queue.close(io);

patches/patches/095_interfaces.patch

@@ -1,5 +1,5 @@
---- exercises/092_interfaces.zig	2023-10-03 22:15:22.125574535 +0200
+--- exercises/095_interfaces.zig	2025-08-15 15:17:57.839348063 +0200
-+++ answers/092_interfaces.zig	2023-10-05 20:04:07.259437354 +0200
++++ answers/095_interfaces.zig	2026-04-03 13:09:13.722917764 +0200
 @@ -106,7 +106,7 @@
      for (my_insects) |insect| {
          // Almost done! We want to print() each insect with a

patches/patches/096_hello_c.patch

@@ -1,5 +1,5 @@
---- exercises/093_hello_c.zig	2023-10-03 22:15:22.125574535 +0200
+--- exercises/096_hello_c.zig	2025-08-15 15:17:57.839348063 +0200
-+++ answers/093_hello_c.zig	2023-10-05 20:04:07.262770750 +0200
++++ answers/096_hello_c.zig	2026-04-03 13:09:26.195163128 +0200
 @@ -54,7 +54,7 @@
      //
      // In this exercise we use 'write' to output 17 chars,

patches/patches/097_bit_manipulation.patch

@@ -1,11 +0,0 @@
---- exercises/097_bit_manipulation.zig	2025-05-12 21:25:03.395385743 +0200
-+++ answers/097_bit_manipulation.zig	2025-05-12 21:22:57.472986976 +0200
-@@ -80,7 +80,7 @@
-     y ^= x;
- 
-     // What must be written here?
--    ???;
-+    x ^= y;
- 
-     print("x = {b}; y = {b}\n", .{ x, y });
- }

patches/patches/097_c_math.patch

@@ -1,5 +1,5 @@
---- exercises/094_c_math.zig	2024-02-28 12:50:35.789939935 +0100
+--- exercises/097_c_math.zig	2025-08-15 15:17:57.839348063 +0200
-+++ answers/094_c_math.zig	2024-02-28 12:53:57.910309471 +0100
++++ answers/097_c_math.zig	2026-04-03 13:09:32.059278502 +0200
 @@ -26,7 +26,7 @@
  
  const c = @cImport({

patches/patches/098_for3.patch

@@ -1,5 +1,5 @@
---- exercises/095_for3.zig	2026-02-27 19:33:59
+--- exercises/098_for3.zig	2026-03-20 19:23:48.873150100 +0100
-+++ answers/095_for3.zig	2026-02-27 19:33:38
++++ answers/098_for3.zig	2026-04-03 13:09:39.916433087 +0200
 @@ -56,7 +56,7 @@
  
      // I want to print every number between 1 and 20 that is NOT

patches/patches/099_memory_allocation.patch

@@ -1,5 +1,5 @@
---- exercises/096_memory_allocation.zig	2023-11-21 14:55:33.805678390 +0100
+--- exercises/099_memory_allocation.zig	2025-08-15 15:17:57.839348063 +0200
-+++ answers/096_memory_allocation.zig	2023-11-21 14:56:00.236163484 +0100
++++ answers/099_memory_allocation.zig	2026-04-03 13:09:47.403580391 +0200
 @@ -64,7 +64,7 @@
      const allocator = arena.allocator();
  

patches/patches/100_bit_manipulation.patch

@@ -0,0 +1,11 @@
+--- exercises/100_bit_manipulation.zig	2025-08-15 15:17:57.839348063 +0200
++++ answers/100_bit_manipulation.zig	2026-04-02 10:51:15.795831343 +0200
+@@ -80,7 +80,7 @@
+     y ^= x;
+ 
+     // What must be written here?
+-    ???;
++    x ^= y;
+ 
+     print("x = {b}; y = {b}\n", .{ x, y });
+ }

patches/patches/101_bit_manipulation2.patch

@@ -1,5 +1,5 @@
---- exercises/098_bit_manipulation2.zig	2023-10-03 22:15:22.125574535 +0200
+--- exercises/101_bit_manipulation2.zig	2025-08-15 15:17:57.839348063 +0200
-+++ answers/098_bit_manipulation2.zig	2023-10-05 20:04:07.286104520 +0200
++++ answers/101_bit_manipulation2.zig	2026-04-02 10:51:15.797831382 +0200
 @@ -60,5 +60,5 @@
      // and if so, we know the given string is a pangram
      //

patches/patches/102_formatting.patch

@@ -1,5 +1,5 @@
---- exercises/099_formatting.zig	2024-11-07 21:45:10.459123650 +0100
+--- exercises/102_formatting.zig	2026-03-20 19:23:48.873150100 +0100
-+++ answers/099_formatting.zig	2024-11-07 21:43:55.154345991 +0100
++++ answers/102_formatting.zig	2026-04-02 10:51:15.799831421 +0200
 @@ -131,7 +131,7 @@
          for (0..size) |b| {
              // What formatting is needed here to make our columns

patches/patches/103_for4.patch

@@ -1,5 +1,5 @@
---- exercises/100_for4.zig	2023-10-03 22:15:22.125574535 +0200
+--- exercises/103_for4.zig	2025-08-15 15:17:57.839348063 +0200
-+++ answers/100_for4.zig	2023-10-05 20:04:07.296104707 +0200
++++ answers/103_for4.zig	2026-04-02 10:51:15.801831460 +0200
 @@ -39,7 +39,7 @@
      const hex_nums = [_]u8{ 0xb, 0x2a, 0x77 };
      const dec_nums = [_]u8{ 11, 42, 119 };

patches/patches/104_for5.patch

@@ -1,5 +1,5 @@
---- exercises/101_for5.zig	2023-10-03 22:15:22.125574535 +0200
+--- exercises/104_for5.zig	2025-08-15 15:17:57.839348063 +0200
-+++ answers/101_for5.zig	2023-10-05 20:04:07.299438103 +0200
++++ answers/104_for5.zig	2026-04-02 10:51:15.803831499 +0200
 @@ -51,7 +51,7 @@
  
      // We would like to number our list starting with 1, not 0.

patches/patches/105_testing.patch

@@ -1,5 +1,5 @@
---- exercises/102_testing.zig	2025-10-24 12:54:56
+--- exercises/105_testing.zig	2026-03-20 19:23:48.873150100 +0100
-+++ answers/102_testing.zig	2025-10-24 12:56:33
++++ answers/105_testing.zig	2026-04-02 10:51:15.805831538 +0200
 @@ -71,7 +71,7 @@
  // The corresponding test is not much different from the previous one. Except
  // that it contains an error that you need to correct.

patches/patches/106_tokenization.patch

@@ -1,5 +1,5 @@
---- exercises/103_tokenization.zig	2026-02-27 19:25:11
+--- exercises/106_tokenization.zig	2026-03-20 19:23:48.873150100 +0100
-+++ answers/103_tokenization.zig	2026-02-27 19:26:04
++++ answers/106_tokenization.zig	2026-04-02 10:51:15.807831578 +0200
 @@ -134,7 +134,7 @@
      ;
  

patches/patches/107_threading.patch

@@ -1,5 +1,5 @@
---- exercises/104_threading.zig	2026-04-01 23:31:10.073198955 +0200
+--- exercises/107_threading.zig	2026-04-01 23:31:10.073198955 +0200
-+++ answers/104_threading.zig	2026-04-01 23:29:51.314585919 +0200
++++ answers/107_threading.zig	2026-04-02 10:51:15.809831617 +0200
 @@ -88,12 +88,12 @@
          defer handle.join();
  

patches/patches/108_threading2.patch

@@ -1,5 +1,5 @@
---- exercises/105_threading2.zig	2024-03-23 16:35:14.754540802 +0100
+--- exercises/108_threading2.zig	2025-08-15 15:17:57.839348063 +0200
-+++ answers/105_threading2.zig	2024-03-23 16:38:00.577539733 +0100
++++ answers/108_threading2.zig	2026-04-02 10:51:15.811831656 +0200
 @@ -81,8 +81,8 @@
          defer handle1.join();
  

patches/patches/109_files.patch

@@ -1,5 +1,5 @@
---- exercises/106_files.zig	2026-01-09 22:41:19.373872684 +0100
+--- exercises/109_files.zig	2026-03-20 19:23:48.874150121 +0100
-+++ answers/106_files.zig	2026-01-09 22:41:44.518372910 +0100
++++ answers/109_files.zig	2026-04-02 10:51:15.813831695 +0200
 @@ -41,7 +41,7 @@
          // by doing nothing
          //

patches/patches/110_files2.patch

@@ -1,5 +1,5 @@
---- exercises/107_files2.zig	2026-01-09 22:43:15.211177186 +0100
+--- exercises/110_files2.zig	2026-03-20 19:23:48.874150121 +0100
-+++ answers/107_files2.zig	2026-01-09 22:42:48.943654602 +0100
++++ answers/110_files2.zig	2026-04-02 10:51:15.815831734 +0200
 @@ -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

patches/patches/111_labeled_switch.patch

@@ -1,6 +1,6 @@
---- exercises/108_labeled_switch.zig	2024-09-20 12:09:24.370066539 +0200
+--- exercises/111_labeled_switch.zig	2025-08-15 15:17:57.840348083 +0200
-+++ answers/108_labeled_switch.zig	2024-09-20 12:09:06.499711739 +0200
++++ answers/111_labeled_switch.zig	2026-04-02 10:51:15.817831773 +0200
-@@ -65,13 +65,13 @@
+@@ -67,13 +67,13 @@
      // how would you fix it?
      pr: switch (PullRequestState.Draft) {
          PullRequestState.Draft => continue :pr PullRequestState.InReview,

patches/patches/112_vectors.patch

@@ -1,5 +1,5 @@
---- exercises/109_vectors.zig	2024-11-07 14:57:09.673383618 +0100
+--- exercises/112_vectors.zig	2025-08-15 15:17:57.840348083 +0200
-+++ answers/109_vectors.zig	2024-11-07 14:22:59.069150138 +0100
++++ answers/112_vectors.zig	2026-04-02 10:51:15.819831812 +0200
 @@ -121,8 +121,8 @@
  
  const Vec4 = @Vector(4, f32);

patches/patches/113_quiz9.patch

@@ -1,6 +1,6 @@
---- exercises/110_quiz9.zig	2025-02-08 13:19:48.522641785 -0800
+--- exercises/113_quiz9.zig	2025-08-15 15:17:57.840348083 +0200
-+++ answers/110_quiz9.zig	2025-02-10 17:42:04.525004335 -0800
++++ answers/113_quiz9.zig	2026-04-02 10:51:15.821831851 +0200
-@@ -108,7 +108,7 @@
+@@ -84,7 +84,7 @@
      PORTB = 0b1100;
      print("  {b:0>4} // (initial state of PORTB)\n", .{PORTB});
      print("^ {b:0>4} // (bitmask)\n", .{0b0101});
@@ -9,7 +9,7 @@
      checkAnswer(0b1001, PORTB);
  
      newline();
-@@ -116,7 +116,7 @@
+@@ -92,7 +92,7 @@
      PORTB = 0b1100;
      print("  {b:0>4} // (initial state of PORTB)\n", .{PORTB});
      print("^ {b:0>4} // (bitmask)\n", .{0b0011});
@@ -18,7 +18,7 @@
      checkAnswer(0b1111, PORTB);
  
      newline();
-@@ -170,7 +170,7 @@
+@@ -103,7 +103,7 @@
      PORTB = 0b1001; // reset PORTB
      print("  {b:0>4} // (initial state of PORTB)\n", .{PORTB});
      print("| {b:0>4} // (bitmask)\n", .{0b0100});
@@ -27,7 +27,7 @@
      checkAnswer(0b1101, PORTB);
  
      newline();
-@@ -178,7 +178,7 @@
+@@ -111,7 +111,7 @@
      PORTB = 0b1001; // reset PORTB
      print("  {b:0>4} // (reset state)\n", .{PORTB});
      print("| {b:0>4} // (bitmask)\n", .{0b0100});
@@ -36,7 +36,7 @@
      checkAnswer(0b1101, PORTB);
  
      newline();
-@@ -269,7 +269,7 @@
+@@ -122,7 +122,7 @@
      PORTB = 0b1110; // reset PORTB
      print("  {b:0>4} // (initial state of PORTB)\n", .{PORTB});
      print("& {b:0>4} // (bitmask)\n", .{0b1011});
@@ -45,7 +45,7 @@
      checkAnswer(0b1010, PORTB);
  
      newline();
-@@ -277,7 +277,7 @@
+@@ -130,7 +130,7 @@
      PORTB = 0b0111; // reset PORTB
      print("  {b:0>4} // (reset state)\n", .{PORTB});
      print("& {b:0>4} // (bitmask)\n", .{0b1110});

patches/patches/114_packed.patch

@@ -1,5 +1,5 @@
---- exercises/111_packed.zig	2026-03-13 11:18:44
+--- exercises/114_packed.zig	2026-03-20 19:23:48.874150121 +0100
-+++ answers/111_packed.zig	2026-03-13 11:18:57
++++ answers/114_packed.zig	2026-04-02 10:51:15.824831910 +0200
 @@ -41,7 +41,7 @@
  
  const PackedStruct = packed struct {

patches/patches/115_packed2.patch

@@ -1,5 +1,5 @@
---- exercises/112_packed2.zig	2026-03-13 11:14:08
+--- exercises/115_packed2.zig	2026-03-20 19:23:48.874150121 +0100
-+++ answers/112_packed2.zig	2026-03-13 11:14:16
++++ answers/115_packed2.zig	2026-04-02 10:51:15.826831949 +0200
 @@ -13,9 +13,9 @@
      const s: S = .{ .a = true, .b = -1 };
      switch (s) {