CONTRIBUTING.md

@@ -12,10 +12,10 @@ the current Zig snapshot, setup a copy of Ziglings, and knows
 common language building blocks (if/then/else, loops, and
 functions) is ready for Ziglings.
 
-Zigling's excercises are self-contained. If you can't solve
-an exercise from the information you've gleaned so far from
-Ziglings, then the exercise probably needs some additional work.
-Please file an issue!
+Ziglings is intended to be completely self-contained. If you
+can't solve an exercise from the information you've gleaned so
+far from Ziglings, then the exercise probably needs some
+additional work. Please file an issue!
 
 If an example doesn't match a description or if something is
 unclear, please file an issue!
@@ -52,8 +52,6 @@ If you run into an error in Ziglings caused by breaking changes
 in the latest development build of Zig, that's a new bug in
 Ziglings. Please file an issue...or make a pull request!
 
-For the latter, also read "The Secrets” section.
-
 
 ## Formatting
 
@@ -91,23 +89,3 @@ contribution for any other purpose.
 
 If you want to peek at the secrets, take a look at the `patches/`
 directory.
-
-Every Ziglings exercise contains mistakes on purpose.
-To keep our automated tests happy, each exercise also
-has a patch in `patches/healed` that “heals” it.
-
-When you change an exercise, you will usually need to update
-its patch too. That’s where our little helper Gollum comes in:
-
-  1. In the project root, create a folder called `answers/`
-  2. Put your solved version of the exercise file in there
-  3. Back in the root, run:
-     `./patches/gollum <exercise-number>`<br>
-     For example: `./patches/gollum 106`
-     This will generate a shiny new patch.
-
-Double-check everything by asking the magical Eowyn:
-`./patches/eowyn`<br>
-If all tests pass: You are done!
-
-Don’t forget to commit the patch file.

README.md

@@ -25,9 +25,10 @@ language such as C.
 
 Each exercise is self-contained and self-explained. However,
 you're encouraged to also check out these Zig language resources
-for more details:
+for more detail:
 
 * https://ziglang.org/learn/
+* https://ziglearn.org/
 * https://ziglang.org/documentation/master/
 * [Zig in Depth! (video series)](https://www.youtube.com/watch?v=MMtvGA1YhW4&list=PLtB7CL7EG7pCw7Xy1SQC53Gl8pI7aDg9t&pp=iAQB)
 
@@ -44,7 +45,7 @@ Verify the installation and build number of `zig` like so:
 
 ```
 $ zig version
-0.16.0-dev.xxxx+xxxxxxxxx
+0.15.0-dev.xxxx+xxxxxxxxx
 ```
 
 Clone this repository with Git:
@@ -72,8 +73,8 @@ the appropriate tag.
 The Zig language is under very active development. In order to be
 current, Ziglings tracks **development** builds of the Zig
 compiler rather than versioned **release** builds. The last
-stable release was `0.15.1`, but Ziglings needs a dev build with
-pre-release version "0.16.0" and a build number at least as high
+stable release was `0.14.1`, but Ziglings needs a dev build with
+pre-release version "0.15.0" and a build number at least as high
 as that shown in the example version check above.
 
 It is likely that you'll download a build which is _greater_ than
@@ -86,7 +87,6 @@ that if you update one, you may need to also update the other.
 
 ### Version Changes
 
-* *2025-09-03* zig 0.16.0-dev.164 - changes in reader, see [#25077](https://github.com/ziglang/zig/pull/25077)
 * *2025-08-15* zig 0.15.0-dev.1519 - changes in array list, see [#24801](https://github.com/ziglang/zig/pull/24801)
 * *2025-08-08* zig 0.15.0-dev.1380 - changes in build system, see [#24588](https://github.com/ziglang/zig/pull/24588)
 * *2025-07-22* zig 0.15.0-dev.1092 - various changes due to new I/O API, see [#24488](https://github.com/ziglang/zig/pull/24488)

build.zig

@@ -15,7 +15,7 @@ const print = std.debug.print;
 //     1) Getting Started
 //     2) Version Changes
 comptime {
-    const required_zig = "0.16.0-dev.164";
+    const required_zig = "0.15.0-dev.1519";
     const current_zig = builtin.zig_version;
     const min_zig = std.SemanticVersion.parse(required_zig) catch unreachable;
     if (current_zig.order(min_zig) == .lt) {
@@ -276,12 +276,8 @@ pub fn build(b: *Build) !void {
         var gpa = std.heap.GeneralPurposeAllocator(.{}){};
         defer _ = gpa.deinit();
         const allocator = gpa.allocator();
-        const contents = try allocator.alloc(u8, progress_file_size);
+        const contents = try progress_file.readToEndAlloc(allocator, progress_file_size);
         defer allocator.free(contents);
-        const bytes_read = try progress_file.read(contents);
-        if (bytes_read != progress_file_size) {
-            return error.UnexpectedEOF;
-        }
 
         starting_exercise = try std.fmt.parseInt(u32, contents, 10);
     } else |err| {
@@ -512,10 +508,6 @@ const ZiglingStep = struct {
             zig_args.append("-lc") catch @panic("OOM");
         }
 
-        if (b.reference_trace) |rt| {
-            zig_args.append(b.fmt("-freference-trace={}", .{rt})) catch @panic("OOM");
-        }
-
         zig_args.append(b.pathFromRoot(path)) catch @panic("OOM");
 
         zig_args.append("--cache-dir") catch @panic("OOM");
@@ -570,7 +562,7 @@ const ZiglingStep = struct {
 
         // Render compile errors at the bottom of the terminal.
         // TODO: use the same ttyconf from the builder.
-        const ttyconf: std.Io.tty.Config = if (use_color_escapes)
+        const ttyconf: std.io.tty.Config = if (use_color_escapes)
             .escape_codes
         else
             .no_color;

exercises/019_functions2.zig

@@ -3,7 +3,7 @@
 // example that takes two parameters. As you can see, parameters
 // are declared just like any other types ("name": "type"):
 //
-//     fn myFunction(number: u8, is_lucky: bool) void {
+//     fn myFunction(number: u8, is_lucky: bool) {
 //         ...
 //     }
 //

exercises/102_testing.zig

@@ -58,7 +58,7 @@ test "add" {
 
     // Another way to perform this test
     // is as follows:
-    try testing.expectEqual(42, add(41, 1));
+    try testing.expectEqual(add(41, 1), 42);
 
     // This time a test with the addition
     // of a negative number:

exercises/106_files.zig

@@ -63,9 +63,8 @@ pub fn main() !void {
 }
 // to check if you actually write to the file, you can either,
 // 1. open the file in your text editor, or
-// 2. print the content of the file in the console with one of these commands
-//    Linux/macOS:   >> cat ./output/zigling.txt
-//    Windows (CMD): >> type .\output\zigling.txt
+// 2. print the content of the file in the console with the following command
+//    >> cat ./output/zigling.txt
 //
 //
 // More on Creating files

exercises/107_files2.zig

@@ -2,7 +2,7 @@
 // Prerequisite :
 //    - exercise/106_files.zig, or
 //    - create a file {project_root}/output/zigling.txt
-//      with content `It's zigling time!`(18 bytes total)
+//      with content `It's zigling time!`(18 byte total)
 //
 // Now there's no point in writing to a file if we don't read from it, am I right?
 // Let's write a program to read the content of the file that we just created.

patches/patches/106_files.patch

@@ -1,5 +1,5 @@
---- exercises/106_files.zig	2025-08-24 19:23:55.168565003 +0200
-+++ answers/106_files.zig	2025-08-24 19:25:37.745597511 +0200
+--- exercises/106_files.zig	2025-03-13 15:26:59.532367792 +0200
++++ answers/106_files.zig	2025-03-14 22:04:52.243435159 +0200
 @@ -35,7 +35,7 @@
          // by doing nothing
          //

patches/patches/107_files2.patch

@@ -1,5 +1,5 @@
---- exercises/107_files2.zig	2025-08-24 19:15:17.789371332 +0200
-+++ answers/107_files2.zig	2025-08-24 19:17:58.897538288 +0200
+--- exercises/107_files2.zig	2025-03-13 15:26:59.532367792 +0200
++++ answers/107_files2.zig	2025-03-14 22:08:35.167953736 +0200
 @@ -33,7 +33,7 @@
      // initialize an array of u8 with all letter 'A'
      // we need to pick the size of the array, 64 seems like a good number