some exercises

Reviewed-on: https://codeberg.org/ziglings/exercises/pulls/95

.devcontainer/devcontainer.json

@@ -0,0 +1,31 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/debian
+{
+	"name": "Ziglings",
+	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
+	"image": "mcr.microsoft.com/devcontainers/base:bullseye",
+	"features": {
+		"ghcr.io/devcontainers-contrib/features/zig:1": {
+			"version": "master"
+		}
+	},
+	"customizations": {
+		"vscode": {
+			"extensions": [
+				"ziglang.vscode-zig"
+			]
+		}
+	}
+
+	// Features to add to the dev container. More info: https://containers.dev/features.
+	// "features": {},
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+
+	// Configure tool-specific properties.
+	// "customizations": {},
+
+	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
+	// "remoteUser": "root"
+}

.woodpecker/eowyn.yaml

@@ -1,6 +1,7 @@
 steps:
   - name: eowyn
-    image: ziglings/ziglang
+    image: ziglings/ziglang:latest
+    pull: true
     commands:
       - sh ./patches/eowyn.sh
     when:

README.md

@@ -46,7 +46,7 @@ Verify the installation and build number of `zig` like so:
 
 ```
 $ zig version
-0.12.0-dev.xxxx+xxxxxxxxx
+0.13.0-dev.xxxx+xxxxxxxxx
 ```
 
 Clone this repository with Git:
@@ -74,8 +74,8 @@ 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 `0.11.0`, but Ziglings needs a dev build with
+stable release was `0.12.0`, but Ziglings needs a dev build with
-pre-release version "0.12.0" and a build number at least as high
+pre-release version "0.13.0" 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

build.zig

@@ -1128,7 +1128,7 @@ const exercises = [_]Exercise{
         .main_file = "107_files2.zig",
         .output =
         \\AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
-        \\Successfully Read 18 byte: It's zigling time!
+        \\Successfully Read 18 bytes: It's zigling time!
         ,
     },
     .{

exercises/001_hello.zig

@@ -16,6 +16,6 @@
 //
 const std = @import("std");
 
-fn main() void {
+pub fn main() void {
     std.debug.print("Hello world!\n", .{});
 }

exercises/002_std.zig

@@ -11,7 +11,7 @@
 // Please complete the import below:
 //
 
-??? = @import("std");
+const std = @import("std");
 
 pub fn main() void {
     std.debug.print("Standard Library.\n", .{});

exercises/003_assignment.zig

@@ -34,12 +34,12 @@
 const std = @import("std");
 
 pub fn main() void {
-    const n: u8 = 50;
+    var n: u8 = 50;
     n = n + 5;
 
-    const pi: u8 = 314159;
+    const pi: u32 = 314159;
 
-    const negative_eleven: u8 = -11;
+    const negative_eleven: i8 = -11;
 
     // There are no errors in the next line, just explanation:
     // Perhaps you noticed before that the print function takes two

exercises/004_arrays.zig

@@ -27,7 +27,7 @@ pub fn main() void {
     // (Problem 1)
     // This "const" is going to cause a problem later - can you see what it is?
     // How do we fix it?
-    const some_primes = [_]u8{ 1, 3, 5, 7, 11, 13, 17, 19 };
+    var some_primes = [_]u8{ 1, 3, 5, 7, 11, 13, 17, 19 };
 
     // Individual values can be set with '[]' notation.
     // Example: This line changes the first prime to 2 (which is correct):
@@ -40,11 +40,11 @@ pub fn main() void {
     // (Problem 2)
     // Looks like we need to complete this expression. Use the example
     // above to set "fourth" to the fourth element of the some_primes array:
-    const fourth = some_primes[???];
+    const fourth = some_primes[3];
 
     // (Problem 3)
     // Use the len property to get the length of the array:
-    const length = some_primes.???;
+    const length = some_primes.len;
 
     std.debug.print("First: {}, Fourth: {}, Length: {}\n", .{
         first, fourth, length,

exercises/005_arrays2.zig

@@ -25,12 +25,12 @@ pub fn main() void {
     // (Problem 1)
     // Please set this array concatenating the two arrays above.
     // It should result in: 1 3 3 7
-    const leet = ???;
+    const leet = le ++ et;
 
     // (Problem 2)
     // Please set this array using repetition.
     // It should result in: 1 0 0 1 1 0 0 1 1 0 0 1
-    const bit_pattern = [_]u8{ ??? } ** 3;
+    const bit_pattern = [_]u8{ 1, 0, 0, 1 } ** 3;
 
     // Okay, that's all of the problems. Let's see the results.
     //

exercises/006_strings.zig

@@ -24,18 +24,18 @@ pub fn main() void {
     // (Problem 1)
     // Use array square bracket syntax to get the letter 'd' from
     // the string "stardust" above.
-    const d: u8 = ziggy[???];
+    const d: u8 = ziggy[4];
 
     // (Problem 2)
     // Use the array repeat '**' operator to make "ha ha ha ".
-    const laugh = "ha " ???;
+    const laugh = "ha " ** 3;
 
     // (Problem 3)
     // Use the array concatenation '++' operator to make "Major Tom".
     // (You'll need to add a space as well!)
     const major = "Major";
     const tom = "Tom";
-    const major_tom = major ??? tom;
+    const major_tom = major ++ " " ++ tom;
 
     // That's all the problems. Let's see our results:
     std.debug.print("d={u} {s}{s}\n", .{ d, laugh, major_tom });

exercises/007_strings2.zig

@@ -15,9 +15,9 @@ const std = @import("std");
 
 pub fn main() void {
     const lyrics =
-        Ziggy played guitar
+        \\Ziggy played guitar
-        Jamming good with Andrew Kelley
+        \\Jamming good with Andrew Kelley
-        And the Spiders from Mars
+        \\And the Spiders from Mars
     ;
 
     std.debug.print("{s}\n", .{lyrics});

exercises/008_quiz.zig

@@ -19,7 +19,7 @@ pub fn main() void {
     // the idiomatic type to use for array indexing.
     //
     // There IS a problem on this line, but 'usize' isn't it.
-    const x: usize = 1;
+    var x: usize = 1;
 
     // Note: When you want to declare memory (an array in this
     // case) without putting anything in it, you can set it to
@@ -33,10 +33,10 @@ pub fn main() void {
     lang[0] = letters[x];
 
     x = 3;
-    lang[???] = letters[x];
+    lang[1] = letters[x];
 
-    x = ???;
+    x = 5;
-    lang[2] = letters[???];
+    lang[2] = letters[x];
 
     // We want to "Program in Zig!" of course:
     std.debug.print("Program in {s}!\n", .{lang});

exercises/009_if.zig

@@ -24,7 +24,7 @@ pub fn main() void {
     const foo = 1;
 
     // Please fix this condition:
-    if (foo) {
+    if (foo == 1) {
         // We want our program to print this message!
         std.debug.print("Foo is 1!\n", .{});
     } else {

exercises/010_if2.zig

@@ -10,7 +10,7 @@ pub fn main() void {
 
     // Please use an if...else expression to set "price".
     // If discount is true, the price should be $17, otherwise $20:
-    const price: u8 = if ???;
+    const price: u8 = if (discount) 17 else 20;
 
     std.debug.print("With the discount, the price is ${}.\n", .{price});
 }

exercises/011_while.zig

@@ -21,7 +21,7 @@ pub fn main() void {
     var n: u32 = 2;
 
     // Please use a condition that is true UNTIL "n" reaches 1024:
-    while (???) {
+    while (n < 1024) {
         // Print the current number
         std.debug.print("{} ", .{n});
 

exercises/012_while2.zig

@@ -25,7 +25,7 @@ pub fn main() void {
 
     // Please set the continue expression so that we get the desired
     // results in the print statement below.
-    while (n < 1000) : ??? {
+    while (n < 1000) : (n *= 2) {
         // Print the current number
         std.debug.print("{} ", .{n});
     }

exercises/013_while3.zig

@@ -24,8 +24,8 @@ pub fn main() void {
     while (n <= 20) : (n += 1) {
         // The '%' symbol is the "modulo" operator and it
         // returns the remainder after division.
-        if (n % 3 == 0) ???;
+        if (n % 3 == 0) continue;
-        if (n % 5 == 0) ???;
+        if (n % 5 == 0) continue;
         std.debug.print("{} ", .{n});
     }
 

exercises/014_while4.zig

@@ -18,7 +18,7 @@ pub fn main() void {
     // Oh dear! This while loop will go forever?!
     // Please fix this so the print statement below gives the desired output.
     while (true) : (n += 1) {
-        if (???) ???;
+        if (n > 3) break;
     }
 
     // Result: we want n=4

exercises/015_for.zig

@@ -15,7 +15,7 @@ pub fn main() void {
 
     std.debug.print("A Dramatic Story: ", .{});
 
-    for (???) |???| {
+    for (story) |scene| {
         if (scene == 'h') std.debug.print(":-)  ", .{});
         if (scene == 's') std.debug.print(":-(  ", .{});
         if (scene == 'n') std.debug.print(":-|  ", .{});

exercises/016_for2.zig

@@ -25,7 +25,7 @@ pub fn main() void {
     // the value of the place as a power of two for each bit.
     //
     // See if you can figure out the missing pieces:
-    for (bits, ???) |bit, ???| {
+    for (bits, 0..) |bit, i| {
         // Note that we convert the usize i to a u32 with
         // @intCast(), a builtin function just like @import().
         // We'll learn about these properly in a later exercise.

exercises/017_quiz2.zig

@@ -9,18 +9,18 @@
 // Let's go from 1 to 16. This has been started for you, but there
 // are some problems. :-(
 //
-const std = import standard library;
+const std = @import("std");
 
-function main() void {
+pub fn main() void {
     var i: u8 = 1;
     const stop_at: u8 = 16;
 
     // What kind of loop is this? A 'for' or a 'while'?
-    ??? (i <= stop_at) : (i += 1) {
+    while (i <= stop_at) : (i += 1) {
         if (i % 3 == 0) std.debug.print("Fizz", .{});
         if (i % 5 == 0) std.debug.print("Buzz", .{});
         if (!(i % 3 == 0) and !(i % 5 == 0)) {
-            std.debug.print("{}", .{???});
+            std.debug.print("{}", .{i});
         }
         std.debug.print(", ", .{});
     }

exercises/018_functions.zig

@@ -25,6 +25,6 @@ pub fn main() void {
 // We're just missing a couple things. One thing we're NOT missing is the
 // keyword "pub", which is not needed here. Can you guess why?
 //
-??? deepThought() ??? {
+fn deepThought() u8 {
     return 42; // Number courtesy Douglas Adams
 }

exercises/019_functions2.zig

@@ -22,7 +22,7 @@ pub fn main() void {
 // You'll need to figure out the parameter name and type that we're
 // expecting. The output type has already been specified for you.
 //
-fn twoToThe(???) u32 {
+fn twoToThe(my_number: u8) u32 {
     return std.math.pow(u32, 2, my_number);
     // std.math.pow(type, a, b) takes a numeric type and two
     // numbers of that type (or that can coerce to that type) and

exercises/020_quiz3.zig

@@ -21,8 +21,8 @@ pub fn main() void {
 //
 // This function prints, but does not return anything.
 //
-fn printPowersOfTwo(numbers: [4]u16) ??? {
+fn printPowersOfTwo(numbers: [4]u16) void {
-    loop (numbers) |n| {
+    for (numbers) |n| {
         std.debug.print("{} ", .{twoToThe(n)});
     }
 }
@@ -31,13 +31,13 @@ fn printPowersOfTwo(numbers: [4]u16) ??? {
 // exercise. But don't be fooled! This one does the math without the aid
 // of the standard library!
 //
-fn twoToThe(number: u16) ??? {
+fn twoToThe(number: u16) u32 {
     var n: u16 = 0;
     var total: u16 = 1;
 
-    loop (n < number) : (n += 1) {
+    while (n < number) : (n += 1) {
         total *= 2;
     }
 
-    return ???;
+    return total;
 }

exercises/021_errors.zig

@@ -9,7 +9,7 @@
 // "TooSmall". Please add it where needed!
 const MyNumberError = error{
     TooBig,
-    ???,
+    TooSmall,
     TooFour,
 };
 
@@ -26,7 +26,7 @@ pub fn main() void {
         if (number_error == MyNumberError.TooBig) {
             std.debug.print(">4. ", .{});
         }
-        if (???) {
+        if (number_error == MyNumberError.TooSmall) {
             std.debug.print("<4. ", .{});
         }
         if (number_error == MyNumberError.TooFour) {

exercises/022_errors2.zig

@@ -19,7 +19,7 @@ const std = @import("std");
 const MyNumberError = error{TooSmall};
 
 pub fn main() void {
-    var my_number: ??? = 5;
+    var my_number: MyNumberError!u8 = 5;
 
     // Looks like my_number will need to either store a number OR
     // an error. Can you set the type correctly above?

exercises/023_errors3.zig

@@ -12,14 +12,14 @@ const MyNumberError = error{TooSmall};
 
 pub fn main() void {
     const a: u32 = addTwenty(44) catch 22;
-    const b: u32 = addTwenty(4) ??? 22;
+    const b: u32 = addTwenty(4) catch 22;
 
     std.debug.print("a={}, b={}\n", .{ a, b });
 }
 
 // Please provide the return type from this function.
 // Hint: it'll be an error union.
-fn addTwenty(n: u32) ??? {
+fn addTwenty(n: u32) MyNumberError!u32 {
     if (n < 5) {
         return MyNumberError.TooSmall;
     } else {

exercises/024_errors4.zig

@@ -59,7 +59,12 @@ fn fixTooSmall(n: u32) MyNumberError!u32 {
     // If we get a TooSmall error, we should return 10.
     // If we get any other error, we should return that error.
     // Otherwise, we return the u32 number.
-    return detectProblems(n) ???;
+    return detectProblems(n) catch |err| {
+        if (err == MyNumberError.TooSmall) {
+            return 10;
+        }
+        return err;
+    };
 }
 
 fn detectProblems(n: u32) MyNumberError!u32 {

exercises/025_errors5.zig

@@ -26,7 +26,7 @@ fn addFive(n: u32) MyNumberError!u32 {
     // This function needs to return any error which might come back from detect().
     // Please use a "try" statement rather than a "catch".
     //
-    const x = detect(n);
+    const x = try detect(n);
 
     return x + 5;
 }

exercises/026_hello2.zig

@@ -23,5 +23,5 @@ pub fn main() !void {
     // to be able to pass it up as a return value of main().
     //
     // We just learned of a single statement which can accomplish this.
-    stdout.print("Hello world!\n", .{});
+    try stdout.print("Hello world!\n", .{});
 }

exercises/027_defer.zig

@@ -20,6 +20,6 @@ const std = @import("std");
 pub fn main() void {
     // Without changing anything else, please add a 'defer' statement
     // to this code so that our program prints "One Two\n":
-    std.debug.print("Two\n", .{});
+    defer std.debug.print("Two\n", .{});
     std.debug.print("One ", .{});
 }

exercises/028_defer2.zig

@@ -18,7 +18,7 @@ pub fn main() void {
 fn printAnimal(animal: u8) void {
     std.debug.print("(", .{});
 
-    std.debug.print(") ", .{}); // <---- how?!
+    defer std.debug.print(") ", .{}); // <---- how?!
 
     if (animal == 'g') {
         std.debug.print("Goat", .{});

exercises/029_errdefer.zig

@@ -32,7 +32,7 @@ fn makeNumber() MyErr!u32 {
 
     // Please make the "failed" message print ONLY if the makeNumber()
     // function exits with an error:
-    std.debug.print("failed!\n", .{});
+    errdefer std.debug.print("failed!\n", .{});
 
     var num = try getNumber(); // <-- This could fail!
 

exercises/030_switch.zig

@@ -46,6 +46,7 @@ pub fn main() void {
             // match for every possible value).  Please add an "else"
             // to this switch to print a question mark "?" when c is
             // not one of the existing matches.
+            else => std.debug.print("?", .{}),
         }
     }
 

exercises/031_switch2.zig

@@ -31,6 +31,7 @@ pub fn main() void {
             26 => 'Z',
             // As in the last exercise, please add the 'else' clause
             // and this time, have it return an exclamation mark '!'.
+            else => '!',
         };
 
         std.debug.print("{c}", .{real_char});

exercises/032_unreachable.zig

@@ -35,6 +35,7 @@ pub fn main() void {
             3 => {
                 current_value *= current_value;
             },
+            else => unreachable,
         }
 
         std.debug.print("{} ", .{current_value});

exercises/033_iferror.zig

@@ -39,7 +39,7 @@ pub fn main() void {
             std.debug.print("={}. ", .{value});
         } else |err| switch (err) {
             MyNumberError.TooBig => std.debug.print(">4. ", .{}),
-            // Please add a match for TooSmall here and have it print: "<4. "
+            MyNumberError.TooSmall => std.debug.print("<4. ", .{}),
         }
     }
 

exercises/034_quiz4.zig

@@ -6,14 +6,11 @@
 //     my_num=42
 //
 const std = @import("std");
-
 const NumError = error{IllegalNumber};
 
-pub fn main() void {
+pub fn main() !void {
     const stdout = std.io.getStdOut().writer();
-
+    const my_num: u32 = try getNumber();
-    const my_num: u32 = getNumber();
-
     try stdout.print("my_num={}\n", .{my_num});
 }
 

exercises/035_enums.zig

@@ -20,7 +20,7 @@
 const std = @import("std");
 
 // Please complete the enum!
-const Ops = enum { ??? };
+const Ops = enum { inc, dec, pow };
 
 pub fn main() void {
     const operations = [_]Ops{

exercises/036_enums2.zig

@@ -31,7 +31,7 @@ const std = @import("std");
 const Color = enum(u32) {
     red = 0xff0000,
     green = 0x00ff00,
-    blue = ???,
+    blue = 0x0000ff,
 };
 
 pub fn main() void {
@@ -53,12 +53,12 @@ pub fn main() void {
         \\<p>
         \\  <span style="color: #{x:0>6}">Red</span>
         \\  <span style="color: #{x:0>6}">Green</span>
-        \\  <span style="color: #{}">Blue</span>
+        \\  <span style="color: #{x:0>6}">Blue</span>
         \\</p>
         \\
     , .{
         @intFromEnum(Color.red),
         @intFromEnum(Color.green),
-        @intFromEnum(???), // Oops! We're missing something!
+        @intFromEnum(Color.blue), // Oops! We're missing something!
     });
 }

exercises/046_optionals2.zig

@@ -51,8 +51,6 @@ fn visitElephants(first_elephant: *Elephant) void {
         // We should stop once we encounter a tail that
         // does NOT point to another element. What can
         // we put here to make that happen?
-        if (e.tail == null) ???;
+        e = e.tail ???
-
-        e = e.tail.?;
     }
 }

exercises/094_c_math.zig

@@ -13,7 +13,7 @@
 // How could we do that? A good method is to use the modulo function.
 // But if we write "765.2 % 360", it only works with float values
 // that are known at compile time.
-// In Zig, we would use %mod(a, b) instead.
+// In Zig, we would use @mod(a, b) instead.
 //
 // Let us now assume that we cannot do this in Zig, but only with
 // a C function from the standard library. In the library "math",

exercises/096_memory_allocation.zig

@@ -30,9 +30,9 @@
 //         std.debug.print("slice_ptr={*}\n", .{slice_ptr});
 //     }
 
-// Instead of a simple integer or a constant sized slice, this
+// Instead of a simple integer or a slice with a constant size,
-// program requires a slice to be allocated that is the same size as
+// this program requires allocating a slice that is the same size
-// an input array.
+// as an input array.
 
 // Given a series of numbers, take the running average. In other
 // words, each item N should contain the average of the last N

exercises/097_bit_manipulation.zig

@@ -1,5 +1,5 @@
 //
-// Bit manipulations is a very powerful tool just also from Zig.
+// Bit manipulation is a very powerful tool, also from Zig.
 // Since the dawn of the computer age, numerous algorithms have been
 // developed that solve tasks solely by moving, setting, or logically
 // combining bits.
@@ -8,10 +8,10 @@
 // functions where possible. And it is often possible with calculations
 // based on integers.
 //
-// Often it is not easy to understand at first glance what exactly these
+// At first glance, it is often not easy to understand what exactly these
 // algorithms do when only "numbers" in memory areas change outwardly.
-// But it must never be forgotten that the numbers only represent the
+// However, it should never be forgotten that the numbers only represent
-// interpretation of the bit sequences.
+// the interpretation of the bit sequences.
 //
 // Quasi the reversed case we have otherwise, namely that we represent
 // numbers in bit sequences.
@@ -21,7 +21,7 @@
 // Zig provides all the necessary functions to change the bits inside
 // a variable. It is distinguished whether the bit change leads to an
 // overflow or not. The details are in the Zig documentation in section
-// 10.1 "Table of Operators".
+// "Table of Operators".
 //
 // Here are some examples of how the bits of variables can be changed:
 //

exercises/098_bit_manipulation2.zig

@@ -1,5 +1,5 @@
 //
-// Another useful practice for bit manipulation is setting bits as flags.
+// Another useful application for bit manipulation is setting bits as flags.
 // This is especially useful when processing lists of something and storing
 // the states of the entries, e.g. a list of numbers and for each prime
 // number a flag is set.
@@ -19,9 +19,9 @@
 // For example, you could take an array of bool and set the value to 'true'
 // for each letter in the order of the alphabet (a=0; b=1; etc.) found in
 // the sentence. However, this is neither memory efficient nor particularly
-// fast. Instead we take a simpler way, very similar in principle, we define
+// fast. Instead we choose a simpler approach that is very similar in principle:
-// a variable with at least 26 bits (e.g. u32) and also set the bit for each
+// We define a variable with at least 26 bits (e.g. u32) and set the bit for
-// letter found at the corresponding position.
+// each letter that is found in the corresponding position.
 //
 // Zig provides functions for this in the standard library, but we prefer to
 // solve it without these extras, after all we want to learn something.
@@ -39,7 +39,7 @@ fn isPangram(str: []const u8) bool {
     // first we check if the string has at least 26 characters
     if (str.len < 26) return false;
 
-    // we uses a 32 bit variable of which we need 26 bits
+    // we use a 32 bit variable of which we need 26 bits
     var bits: u32 = 0;
 
     // loop about all characters in the string

exercises/099_formatting.zig

@@ -19,10 +19,10 @@
 //     https://github.com/ziglang/zig/blob/master/lib/std/fmt.zig#L29
 //
 // Zig already has a very nice selection of formatting options.
-// These can be used in different ways, but typically to convert
+// These can be used in different ways, but generally to convert
-// numerical values into various text representations. The
+// numerical values into various text representations. The results
-// results can be used for direct output to a terminal or stored
+// can be used for direct output to a terminal or stored for
-// for later use or written to a file. The latter is useful when
+// later use or written to a file. The latter is useful when
 // large amounts of data are to be processed by other programs.
 //
 // In Ziglings, we are concerned with the output to the console.

exercises/104_threading.zig

@@ -4,8 +4,8 @@
 // one possibility, namely asynchronous processes, in Exercises 84-91.
 //
 // However, the computing power of the processor is only distributed to
-// the started tasks, which always reaches its limits when pure computing
+// the started and running tasks, which always reaches its limits when
-// power is called up.
+// pure computing power is called up.
 //
 // For example, in blockchains based on proof of work, the miners have
 // to find a nonce for a certain character string so that the first m bits

exercises/105_threading2.zig

@@ -1,6 +1,6 @@
 //
-// Now that we are familiar with the principles of multi threading, we
+// Now that we are familiar with the principles of multi-threading,
-// boldly venture into a practical example from mathematics.
+// let's boldly venture into a practical example from mathematics.
 // We will determine the circle number PI with sufficient accuracy.
 //
 // There are different methods for this, and some of them are several
@@ -104,4 +104,4 @@ fn thread_pi(pi: *f64, begin: u64, end: u64) !void {
 // to such an extent that seconds become minutes during execution.
 //
 // And you should remove the formatting restriction in "print",
-// otherwise you will not be able to see the additional diggits.
+// otherwise you will not be able to see the additional digits.

exercises/106_files.zig

@@ -50,20 +50,20 @@ pub fn main() !void {
     // we try to open the file `zigling.txt`,
     // and propagate the error up if there are any errors
     const file: std.fs.File = try output_dir.createFile("zigling.txt", .{});
-    // it is a good habit to close a file after you are done with
+    // it is a good habit to close a file after you are done with it
-    // so that other program can read it and prevent data corruption
+    // 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 are a keyword in zig that
+    // if only there were a keyword in zig that
-    // allow you "defer" code execute to the end of scope...
+    // allows you "defer" code execute to the end of scope...
     file.close();
 
-    // !you are not allow to switch this two lines to before file closing line!
+    // !you are not allowed to switch these two lines above the file closing line!
     const byte_written = try file.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,
 // 1. open the file on your text editor, or
-// 2. print the content of the file in the console with command
+// 2. print the content of the file in the console with the following command
 //    >> cat ./output/zigling.txt
 //
 //
@@ -89,4 +89,4 @@ pub fn main() !void {
 //   - go to documentation of the struct `std.fs.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 option can you uses with those function?
+//       - what kind of options can you use with those functions?

exercises/107_files2.zig

@@ -5,14 +5,14 @@
 //      with content `It's zigling time!`(18 byte total)
 //
 // Now there no point in writing to a file if we don't read from it am I right?
-// let's wrote a program to read the content of the file that we just created.
+// let's write a program to read the content of the file that we just created.
 //
-// I am assuming you've created the appropriate files for this to work.
+// I am assuming that you've created the appropriate files for this to work.
 //
 // Alright, bud, lean in close here's the game plan.
 //    - First, we open the {project_root}/output/ directory
 //    - Secondly, we open file `zigling.txt` in that directory
-//    - then, we initalize an array of character with all letter 'A', and print it
+//    - then, we initalize an array of characters with all letter 'A', and print it
 //    - After that, we read the content of the file to the array
 //    - Finally, we print out the read content
 
@@ -31,22 +31,22 @@ pub fn main() !void {
     defer file.close();
 
     // initalize an array of u8 with all letter 'A'.
-    // we need to pick a size of the array, 64 seems like a good number.
+    // we need to pick the size of the array, 64 seems like a good number.
     // fix the initalization below
     var content = ['A']*64;
     // this should print out : `AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA`
     std.debug.print("{s}\n", .{content});
 
-    // okay, seem like threat of violence is not the answer in this case
+    // okay, seems like a threat of violence is not the answer in this case
     // can you go here to find a way to read the content ?
     // https://ziglang.org/documentation/master/std/#std.fs.File
-    // hint: you might find two answer that are both vaild in this case
+    // hint: you might find two answers that are both vaild in this case
-    const byte_read = zig_read_the_file_or_i_will_fight_you(&content);
+    const bytes_read = zig_read_the_file_or_i_will_fight_you(&content);
 
     // Woah, too screamy, I know you're excited for zigling time but tone it down a bit
     // Can you print only what we read from the file ?
-    std.debug.print("Successfully Read {d} byte: {s}\n", .{
+    std.debug.print("Successfully Read {d} bytes: {s}\n", .{
-        byte_read,
+        bytes_read,
         content, // change this line only
     });
 }

patches/patches/046_optionals2.patch

@@ -1,5 +1,5 @@
---- exercises/046_optionals2.zig	2023-10-03 22:15:22.122241138 +0200
+--- exercises/046_optionals2.zig	2024-05-10 23:11:25.796632478 +0200
-+++ answers/046_optionals2.zig	2023-10-05 20:04:07.049433424 +0200
++++ answers/046_optionals2.zig	2024-05-10 23:10:16.115335668 +0200
 @@ -21,7 +21,7 @@
  
  const Elephant = struct {
@@ -9,12 +9,11 @@
      visited: bool = false,
  };
  
-@@ -51,7 +51,7 @@
+@@ -51,6 +51,6 @@
          // We should stop once we encounter a tail that
          // does NOT point to another element. What can
          // we put here to make that happen?
--        if (e.tail == null) ???;
+-        e = e.tail ???
-+        if (e.tail == null) break;
++        e = e.tail orelse break;
- 
-         e = e.tail.?;
      }
+ }

patches/patches/106_files.patch

@@ -1,5 +1,5 @@
---- exercises/106_files.zig	2024-03-27 16:52:05.660910200 +0800
+--- exercises/106_files.zig	2024-05-05 00:48:25.808548611 +0200
-+++ answers/106_files.zig	2024-03-27 16:52:09.649422200 +0800
++++ answers/106_files.zig	2024-05-05 01:00:40.742969819 +0200
 @@ -35,7 +35,7 @@
          // by doing nothing
          //
@@ -20,10 +20,10 @@
      // we try to open the file `zigling.txt`,
 @@ -55,7 +55,7 @@
      // but here we are not yet done writing to the file
-     // if only there are a keyword in zig that
+     // if only there were a keyword in zig that
-     // allow you "defer" code execute to the end of scope...
+     // allows you "defer" code execute to the end of scope...
 -    file.close();
 +    defer file.close();
  
-     // !you are not allow to switch this two lines to before file closing line!
+     // !you are not allowed to switch these two lines above the file closing line!
      const byte_written = try file.write("It's zigling time!");

patches/patches/107_files2.patch

@@ -1,8 +1,8 @@
---- exercises/107_files2.zig	2024-03-27 16:51:56.199719600 +0800
+--- exercises/107_files2.zig	2024-05-05 00:48:25.808548611 +0200
-+++ answers/107_files2.zig	2024-03-27 16:52:01.650935300 +0800
++++ answers/107_files2.zig	2024-05-05 01:14:03.866062288 +0200
 @@ -33,7 +33,7 @@
      // initalize an array of u8 with all letter 'A'.
-     // we need to pick a size of the array, 64 seems like a good number.
+     // we need to pick the size of the array, 64 seems like a good number.
      // fix the initalization below
 -    var content = ['A']*64;
 +    var content = [_]u8{'A'} ** 64;
@@ -12,15 +12,15 @@
 @@ -41,12 +41,12 @@
      // can you go here to find a way to read the content ?
      // https://ziglang.org/documentation/master/std/#std.fs.File
-     // hint: you might find two answer that are both vaild in this case
+     // hint: you might find two answers that are both vaild in this case
--    const byte_read = zig_read_the_file_or_i_will_fight_you(&content);
+-    const bytes_read = zig_read_the_file_or_i_will_fight_you(&content);
-+    const byte_read = try file.read(&content);
++    const bytes_read = try file.read(&content);
  
      // Woah, too screamy, I know you're excited for zigling time but tone it down a bit
      // Can you print only what we read from the file ?
-     std.debug.print("Successfully Read {d} byte: {s}\n", .{
+     std.debug.print("Successfully Read {d} bytes: {s}\n", .{
-         byte_read,
+         bytes_read,
 -        content, // change this line only
-+        content[0..byte_read], // change this line only
++        content[0..bytes_read], // change this line only
      });
  }