a/ziglings
1
0
Fork 0
mirror of https://codeberg.org/andyscott/ziglings.git synced 2024-12-22 14:03:10 -05:00
Code Issues Projects Releases Packages Wiki Activity

Merge branch 'zig-build' of https://github.com/SpexGuy/ziglings into SpexGuy-zig-build

Browse source
This commit is contained in:
Dave Gauer 2021-02-12 20:49:57 -05:00
commit 37cb6a8b16
5 changed files with 573 additions and 169 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
.gitattributes vendored Normal file
View file

@ -0,0 +1,17 @@
# See https://git-scm.com/docs/gitattributes
# See https://help.github.com/articles/dealing-with-line-endings/
# Default behavior, if core.autocrlf is unset.
* text=auto
# Files to be converted to native line endings on checkout.
*.cpp text
*.h text
# Text files to always have CRLF (dos) line endings on checkout.
*.bat text eol=crlf
# Text files to always have LF (unix) line endings on checkout.
*.sh text eol=lf
*.zig text eol=lf

1
.gitignore vendored
View file

@ -1,2 +1,3 @@
*~
*.swp
zig-cache/

24
README.md
View file

@ -43,20 +43,35 @@ git clone https://github.com/ratfactor/ziglings
cd ziglings
```
Then run the `ziglings` script and follow the instructions to begin!
Then run `zig build` and follow the instructions to begin!
```bash
./ziglings
zig build
```
## Manual Usage
If you can't (or don't want to) use the script, you can manually verify each
exercise with the Zig compiler:
If you want to run a single file for testing, you can do so with this command:
```bash
zig run exercises/01_hello.zig
```
or, alternatively
```bash
zig build 01_test
```
To verify a single file, use
```bash
zig build 01_only
```
To prepare an executable for debugging, install it to zig-cache/bin with
```bash
zig build 01_install
```
## TODO
@ -66,7 +81,6 @@ the learning resource I wished for. There will be tons of room for improvement:
* Wording of explanations
* Idiomatic usage of Zig
* Additional exercises
* Re-write the `ziglings` script using the Zig build system (or just a Zig application)
Planned exercises:

536
build.zig Normal file
View file

@ -0,0 +1,536 @@
const std = @import("std");
const Builder = std.build.Builder;
const Step = std.build.Step;
const assert = std.debug.assert;
const print = std.debug.print;
const Exercise = struct {
/// main_file must have the format key_name.zig.
/// The key will be used as a shorthand to build
/// just one example.
main_file: []const u8,
/// This is the desired output of the program.
/// A program passes if its output ends with this string.
output: []const u8,
/// This is an optional hint to give if the program does not succeed.
hint: []const u8 = "",
/// By default, we verify output against stderr.
/// Set this to true to check stdout instead.
check_stdout: bool = false,
/// Returns the name of the main file with .zig stripped.
pub fn baseName(self: Exercise) []const u8 {
assert(std.mem.endsWith(u8, self.main_file, ".zig"));
return self.main_file[0 .. self.main_file.len - 4];
}
/// Returns the key of the main file, which is the text before the _.
/// For example, "01_hello.zig" has the key "01".
pub fn key(self: Exercise) []const u8 {
const end_index = std.mem.indexOfScalar(u8, self.main_file, '_');
assert(end_index != null); // main file must be key_description.zig
return self.main_file[0..end_index.?];
}
};
const exercises = [_]Exercise{
.{
.main_file = "01_hello.zig",
.output = "Hello world",
.hint = "Note the error: the source file has a hint for fixing 'main'.",
},
.{
.main_file = "02_std.zig",
.output = "Standard Library",
},
.{
.main_file = "03_assignment.zig",
.output = "55 314159 -11",
.hint = "There are three mistakes in this one!",
},
.{
.main_file = "04_arrays.zig",
.output = "Fourth: 7, Length: 8",
.hint = "There are two things to complete here.",
},
.{
.main_file = "05_arrays2.zig",
.output = "LEET: 1337, Bits: 100110011001",
.hint = "Fill in the two arrays.",
},
.{
.main_file = "06_strings.zig",
.output = "d=d ha ha ha Major Tom",
.hint = "Each '???' needs something filled in.",
},
.{
.main_file = "07_strings2.zig",
.output = "Ziggy",
.hint = "Please fix the lyrics!",
},
.{
.main_file = "08_quiz.zig",
.output = "Program in Zig",
.hint = "See if you can fix the program!",
},
.{
.main_file = "09_if.zig",
.output = "Foo is 1!",
},
.{
.main_file = "10_if2.zig",
.output = "price is $17",
},
.{
.main_file = "11_while.zig",
.output = "n=1024",
.hint = "You probably want a 'less than' condition.",
},
.{
.main_file = "12_while2.zig",
.output = "n=1024",
.hint = "It might help to look back at the previous exercise.",
},
.{
.main_file = "13_while3.zig",
.output = "1 2 4 7 8 11 13 14 16 17 19",
},
.{
.main_file = "14_while4.zig",
.output = "n=4",
},
.{
.main_file = "15_for.zig",
.output = "A Dramatic Story: :-) :-) :-( :-| :-) The End.",
},
.{
.main_file = "16_for2.zig",
.output = "13",
},
.{
.main_file = "17_quiz2.zig",
.output = "8, Fizz, Buzz, 11, Fizz, 13, 14, FizzBuzz, 16",
.hint = "This is a famous game!",
},
.{
.main_file = "18_functions.zig",
.output = "Question: 42",
.hint = "Can you help write the function?",
},
.{
.main_file = "19_functions2.zig",
.output = "2 4 8 16",
},
.{
.main_file = "20_quiz3.zig",
.output = "32 64 128 256",
.hint = "Unexpected pop quiz! Help!",
},
.{
.main_file = "21_errors.zig",
.output = "2<4. 3<4. 4=4. 5>4. 6>4.",
.hint = "What's the deal with fours?",
},
.{
.main_file = "22_errors2.zig",
.output = "I compiled",
.hint = "Get the error union type right to allow this to compile.",
},
.{
.main_file = "23_errors3.zig",
.output = "a=64, b=22",
},
.{
.main_file = "24_errors4.zig",
.output = "a=20, b=14, c=10",
},
.{
.main_file = "25_errors5.zig",
.output = "a=0, b=19, c=0",
},
.{
.main_file = "26_hello2.zig",
.output = "Hello world",
.hint = "Try using a try!",
.check_stdout = true,
},
.{
.main_file = "27_defer.zig",
.output = "One Two",
},
.{
.main_file = "28_defer2.zig",
.output = "(Goat) (Cat) (Dog) (Dog) (Goat) (Unknown) done.",
},
.{
.main_file = "29_errdefer.zig",
.output = "Getting number...got 5. Getting number...failed!",
},
.{
.main_file = "30_switch.zig",
.output = "ZIG?",
},
.{
.main_file = "31_switch2.zig",
.output = "ZIG!",
},
.{
.main_file = "32_unreachable.zig",
.output = "1 2 3 9 8 7",
},
.{
.main_file = "33_iferror.zig",
.output = "2<4. 3<4. 4=4. 5>4. 6>4.",
.hint = "Seriously, what's the deal with fours?",
},
.{
.main_file = "34_quiz4.zig",
.output = "my_num=42",
.hint = "Can you make this work?",
.check_stdout = true,
},
.{
.main_file = "35_enums.zig",
.output = "1 2 3 9 8 7",
.hint = "This problem seems familiar...",
},
.{
.main_file = "36_enums2.zig",
.output = "#0000ff",
.hint = "I'm feeling blue about this.",
},
.{
.main_file = "37_structs.zig",
.output = "Your wizard has 90 health and 25 gold.",
},
.{
.main_file = "38_structs2.zig",
.output = "Character 2 - G:10 H:100 XP:20",
},
.{
.main_file = "39_pointers.zig",
.output = "num1: 5, num2: 5",
.hint = "Pointers aren't so bad.",
},
.{
.main_file = "40_pointers2.zig",
.output = "a: 12, b: 12",
},
.{
.main_file = "41_pointers3.zig",
.output = "foo=6, bar=11",
},
.{
.main_file = "42_pointers4.zig",
.output = "num: 5, more_nums: 1 1 5 1",
},
.{
.main_file = "43_pointers5.zig",
.output = "Wizard (G:10 H:100 XP:20)",
},
.{
.main_file = "44_quiz5.zig",
.output = "Elephant A. Elephant B. Elephant C.",
.hint = "Oh no! We forgot Elephant B!",
},
};
/// Check the zig version to make sure it can compile the examples properly.
/// This will compile with Zig 0.6.0 and later.
fn checkVersion() bool {
if (!@hasDecl(std.builtin, "zig_version")) {
return false;
}
const needed_version = std.SemanticVersion.parse("0.8.0-dev.1065") catch unreachable;
const version = std.builtin.zig_version;
const order = version.order(needed_version);
return order != .lt;
}
pub fn build(b: *Builder) void {
// Use a comptime branch for the version check.
// If this fails, code after this block is not compiled.
// It is parsed though, so versions of zig from before 0.6.0
// cannot do the version check and will just fail to compile.
// We could fix this by moving the ziglings code to a separate file,
// but 0.5.0 was a long time ago, it is unlikely that anyone who
// attempts these exercises is still using it.
if (comptime !checkVersion()) {
// very old versions of Zig used warn instead of print.
const stderrPrintFn = if (@hasDecl(std.debug, "print")) std.debug.print else std.debug.warn;
stderrPrintFn(
\\Error: Your version of zig is too old. Please download a master build from
\\https://ziglang.org/download/
\\
, .{});
return;
}
use_color_escapes = false;
switch (b.color) {
.on => use_color_escapes = true,
.off => use_color_escapes = false,
.auto => {
if (std.io.getStdErr().supportsAnsiEscapeCodes()) {
use_color_escapes = true;
} else if (std.builtin.os.tag == .windows) {
const w32 = struct {
const WINAPI = std.os.windows.WINAPI;
const DWORD = std.os.windows.DWORD;
const ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x0004;
const STD_ERROR_HANDLE = @bitCast(DWORD, @as(i32, -12));
extern "kernel32" fn GetStdHandle(id: DWORD) callconv(WINAPI) ?*c_void;
extern "kernel32" fn GetConsoleMode(console: ?*c_void, out_mode: *DWORD) callconv(WINAPI) u32;
extern "kernel32" fn SetConsoleMode(console: ?*c_void, mode: DWORD) callconv(WINAPI) u32;
};
const handle = w32.GetStdHandle(w32.STD_ERROR_HANDLE);
var mode: w32.DWORD = 0;
if (w32.GetConsoleMode(handle, &mode) != 0) {
mode |= w32.ENABLE_VIRTUAL_TERMINAL_PROCESSING;
use_color_escapes = w32.SetConsoleMode(handle, mode) != 0;
}
}
},
}
if (use_color_escapes) {
red_text = "\x1b[31m";
green_text = "\x1b[32m";
bold_text = "\x1b[1m";
reset_text = "\x1b[0m";
}
const header_step = b.addLog(
\\
\\ _ _ _
\\ ___(_) __ _| (_)_ __ __ _ ___
\\ |_ | |/ _' | | | '_ \ / _' / __|
\\ / /| | (_| | | | | | | (_| \__ \
\\ /___|_|\__, |_|_|_| |_|\__, |___/
\\ |___/ |___/
\\
\\
, .{});
const verify_all = b.step("ziglings", "Verify all ziglings");
verify_all.dependOn(&header_step.step);
b.default_step = verify_all;
var prev_chain_verify = verify_all;
for (exercises) |ex| {
const base_name = ex.baseName();
const file_path = std.fs.path.join(b.allocator, &[_][]const u8{
"exercises", ex.main_file,
}) catch unreachable;
const build_step = b.addExecutable(base_name, file_path);
build_step.install();
const verify_step = ZiglingStep.create(b, ex);
const key = ex.key();
const named_test = b.step(b.fmt("{s}_test", .{key}), b.fmt("Run {s} without verifying output", .{ex.main_file}));
const run_step = build_step.run();
named_test.dependOn(&run_step.step);
const named_install = b.step(b.fmt("{s}_install", .{key}), b.fmt("Install {s} to zig-cache/bin", .{ex.main_file}));
named_install.dependOn(&build_step.install_step.?.step);
const named_verify = b.step(b.fmt("{s}_only", .{key}), b.fmt("Verify {s} only", .{ex.main_file}));
named_verify.dependOn(&verify_step.step);
const chain_verify = b.allocator.create(Step) catch unreachable;
chain_verify.* = Step.initNoOp(.Custom, b.fmt("chain {s}", .{key}), b.allocator);
chain_verify.dependOn(&verify_step.step);
const named_chain = b.step(key, b.fmt("Verify all solutions starting at {s}", .{ex.main_file}));
named_chain.dependOn(&header_step.step);
named_chain.dependOn(chain_verify);
prev_chain_verify.dependOn(chain_verify);
prev_chain_verify = chain_verify;
}
}
var use_color_escapes = false;
var red_text: []const u8 = "";
var green_text: []const u8 = "";
var bold_text: []const u8 = "";
var reset_text: []const u8 = "";
const ZiglingStep = struct {
step: Step,
exercise: Exercise,
builder: *Builder,
pub fn create(builder: *Builder, exercise: Exercise) *@This() {
const self = builder.allocator.create(@This()) catch unreachable;
self.* = .{
.step = Step.init(.Custom, exercise.main_file, builder.allocator, make),
.exercise = exercise,
.builder = builder,
};
return self;
}
fn make(step: *Step) anyerror!void {
const self = @fieldParentPtr(@This(), "step", step);
self.makeInternal() catch {
if (self.exercise.hint.len > 0) {
print("\n{s}hint: {s}{s}", .{ bold_text, self.exercise.hint, reset_text });
}
print("\n{s}Edit exercises/{s} and run this again.{s}", .{ red_text, self.exercise.main_file, reset_text });
print("\n{s}To continue from this zigling, use this command:{s}\n {s}zig build {s}{s}\n", .{ red_text, reset_text, bold_text, self.exercise.key(), reset_text });
std.os.exit(0);
};
}
fn makeInternal(self: *@This()) !void {
print("Compiling {s}...\n", .{self.exercise.main_file});
const exe_file = try self.doCompile();
print("Verifying {s}...\n", .{self.exercise.main_file});
const cwd = self.builder.build_root;
const argv = [_][]const u8{exe_file};
const child = std.ChildProcess.init(&argv, self.builder.allocator) catch unreachable;
defer child.deinit();
child.cwd = cwd;
child.env_map = self.builder.env_map;
child.stdin_behavior = .Inherit;
if (self.exercise.check_stdout) {
child.stdout_behavior = .Pipe;
child.stderr_behavior = .Inherit;
} else {
child.stdout_behavior = .Inherit;
child.stderr_behavior = .Pipe;
}
child.spawn() catch |err| {
print("{s}Unable to spawn {s}: {s}{s}\n", .{ red_text, argv[0], @errorName(err), reset_text });
return err;
};
// Allow up to 1 MB of stdout capture
const max_output_len = 1 * 1024 * 1024;
const output = if (self.exercise.check_stdout)
try child.stdout.?.reader().readAllAlloc(self.builder.allocator, max_output_len)
else
try child.stderr.?.reader().readAllAlloc(self.builder.allocator, max_output_len);
// at this point stdout is closed, wait for the process to terminate
const term = child.wait() catch |err| {
print("{s}Unable to spawn {s}: {s}{s}\n", .{ red_text, argv[0], @errorName(err), reset_text });
return err;
};
// make sure it exited cleanly.
switch (term) {
.Exited => |code| {
if (code != 0) {
print("{s}{s} exited with error code {d} (expected {d}){s}\n", .{ red_text, self.exercise.main_file, code, 0, reset_text });
return error.BadExitCode;
}
},
else => {
print("{s}{s} terminated unexpectedly{s}\n", .{ red_text, self.exercise.main_file, reset_text });
return error.UnexpectedTermination;
},
}
// validate the output
if (std.mem.indexOf(u8, output, self.exercise.output) == null) {
print(
\\
\\{s}----------- Expected this output -----------{s}
\\{s}
\\{s}----------- but found -----------{s}
\\{s}
\\{s}-----------{s}
\\
, .{ red_text, reset_text, self.exercise.output, red_text, reset_text, output, red_text, reset_text });
return error.InvalidOutput;
}
print("{s}** PASSED **{s}\n", .{ green_text, reset_text });
}
// The normal compile step calls os.exit, so we can't use it as a library :(
// This is a stripped down copy of std.build.LibExeObjStep.make.
fn doCompile(self: *@This()) ![]const u8 {
const builder = self.builder;
var zig_args = std.ArrayList([]const u8).init(builder.allocator);
defer zig_args.deinit();
zig_args.append(builder.zig_exe) catch unreachable;
zig_args.append("build-exe") catch unreachable;
if (builder.color != .auto) {
zig_args.append("--color") catch unreachable;
zig_args.append(@tagName(builder.color)) catch unreachable;
}
const zig_file = std.fs.path.join(builder.allocator, &[_][]const u8{ "exercises", self.exercise.main_file }) catch unreachable;
zig_args.append(builder.pathFromRoot(zig_file)) catch unreachable;
zig_args.append("--cache-dir") catch unreachable;
zig_args.append(builder.pathFromRoot(builder.cache_root)) catch unreachable;
zig_args.append("--enable-cache") catch unreachable;
const argv = zig_args.items;
var code: u8 = undefined;
const output_dir_nl = builder.execAllowFail(argv, &code, .Inherit) catch |err| {
switch (err) {
error.FileNotFound => {
print("{s}{s}: Unable to spawn the following command: file not found{s}\n", .{ red_text, self.exercise.main_file, reset_text });
for (argv) |v| print("{s} ", .{v});
print("\n", .{});
},
error.ExitCodeFailure => {
print("{s}{s}: The following command exited with error code {}:{s}\n", .{ red_text, self.exercise.main_file, code, reset_text });
for (argv) |v| print("{s} ", .{v});
print("\n", .{});
},
error.ProcessTerminated => {
print("{s}{s}: The following command terminated unexpectedly:{s}\n", .{ red_text, self.exercise.main_file, reset_text });
for (argv) |v| print("{s} ", .{v});
print("\n", .{});
},
else => {},
}
return err;
};
const build_output_dir = std.mem.trimRight(u8, output_dir_nl, "\r\n");
const target_info = std.zig.system.NativeTargetInfo.detect(
builder.allocator,
.{},
) catch unreachable;
const target = target_info.target;
const file_name = std.zig.binNameAlloc(builder.allocator, .{
.root_name = self.exercise.baseName(),
.target = target,
.output_mode = .Exe,
.link_mode = .Static,
.version = null,
}) catch unreachable;
return std.fs.path.join(builder.allocator, &[_][]const u8{
build_output_dir, file_name,
});
}
};

164
ziglings
View file

@ -1,164 +0,0 @@
#!/bin/bash
# ziglings takes one parameter: the exercise number to jump to
jump_to=${1:-0}
echo
echo " _ _ _ "
echo " ___(_) __ _| (_)_ __ __ _ ___ "
echo " |_ | |/ _' | | | '_ \ / _' / __| "
echo " / /| | (_| | | | | | | (_| \__ \ "
echo " /___|_|\__, |_|_|_| |_|\__, |___/ "
echo " |___/ |___/ "
echo
# Capture terminal escape sequences (ANSI) for formatting
fmt_err=$( tput setaf 1 ) # red foreground
fmt_yay=$( tput setaf 2 ) # green foreground
fmt_off=$( tput sgr0 ) # reset colors/effects
zig_cmd=zig
zig_minimum_version="0 8 0 1065"
zig_version=$($zig_cmd version 2>/dev/null)
if [[ "$zig_version" =~ ([0-9]+)\.([0-9]+)\.([0-9]+)-dev\.([0-9]+) ]]
then
match_idx=1 # regex matches start at index 1
for v in $zig_minimum_version
do
if [[ ${BASH_REMATCH[$match_idx]} -lt $v ]]
then
echo "Your current Zig version is $zig_version."
echo "Please update your zig compiler to a version >=$(echo "${zig_minimum_version// /.}") "`
`"or change \$zig_cmd in ./ziglings to the appropriate path."
exit 1
fi
match_idx=$((match_idx+1))
done
elif [[ -z $zig_version ]]
then
echo "Ziglings failed to determine your Zig version."
echo "Please check if \$zig_cmd in ./ziglings matches the zig executable in your PATH."
exit 1
else
echo "Sorry, Zig version number '${zig_version}' is not in the expected format for a current development build."
exit 1
fi
exercise_num=0
function check_it {
source_file="exercises/$1"
correct_output=$2
hint=$3
# If the current exercise is less than the requested one, skip it
let exercise_num+=1
if [[ $exercise_num -lt $jump_to ]]
then
return
fi
# Compile/run the source and capture the result and exit value
cmd="$zig_cmd run $source_file"
echo "$ $cmd"
result=$($cmd 2>&1)
result_status=$?
# Echo the result to the screen so user can see what their program does
echo "$result"
if [[ $result_status -ne 0 ]]
then
echo
printf "${fmt_err}Uh oh! Looks like there was an error.${fmt_off}\n"
if [[ ! -z "$hint" ]]
then
echo "$hint"
fi
echo
echo "Edit '$source_file' and run me again."
echo
exit 1
fi
# Wildcards to be lenient with anything AROUND the correct output
if [[ "$result" == *"$correct_output"* ]]
then
printf "${fmt_yay}** PASSED **${fmt_off}\n"
else
printf "${fmt_err}It seems to compile, but I wanted to see '$correct_output'.${fmt_off}\n"
if [[ ! -z "$hint" ]]
then
echo "$hint"
fi
echo
exit 1
fi
}
# I've chosen to explicitly number AND list each exercise rather than rely
# on sorting. Though it does mean manually renaming things to remove/insert,
# it's worked out well so far.
check_it 01_hello.zig "Hello world" "Note the error: the source file has a hint for fixing 'main'."
check_it 02_std.zig "Standard Library"
check_it 03_assignment.zig "55 314159 -11" "There are three mistakes in this one!"
check_it 04_arrays.zig "Fourth: 7, Length: 8" "There are two things to complete here."
check_it 05_arrays2.zig "LEET: 1337, Bits: 100110011001" "Fill in the two arrays."
check_it 06_strings.zig "d=d ha ha ha Major Tom" "Each '???' needs something filled in."
check_it 07_strings2.zig "Ziggy" "Please fix the lyrics!"
check_it 08_quiz.zig "Program in Zig" "See if you can fix the program!"
check_it 09_if.zig "Foo is 1!"
check_it 10_if2.zig "price is \$17"
check_it 11_while.zig "n=1024" "You probably want a 'less than' condition."
check_it 12_while2.zig "n=1024" "It might help to look back at the previous exercise."
check_it 13_while3.zig "1 2 4 7 8 11 13 14 16 17 19"
check_it 14_while4.zig "n=4"
check_it 15_for.zig "A Dramatic Story: :-) :-) :-( :-| :-) The End."
check_it 16_for2.zig "13"
check_it 17_quiz2.zig "8, Fizz, Buzz, 11, Fizz, 13, 14, FizzBuzz, 16" "This is a famous game!"
check_it 18_functions.zig "Question: 42" "Can you help write the function?"
check_it 19_functions2.zig "2 4 8 16"
check_it 20_quiz3.zig "32 64 128 256" "Unexpected pop quiz! Help!"
check_it 21_errors.zig "2<4. 3<4. 4=4. 5>4. 6>4." "What's the deal with fours?"
check_it 22_errors2.zig "I compiled" "Get the error union type right to allow this to compile."
check_it 23_errors3.zig "a=64, b=22"
check_it 24_errors4.zig "a=20, b=14, c=10"
check_it 25_errors5.zig "a=0, b=19, c=0"
check_it 26_hello2.zig "Hello world" "Try using a try!"
check_it 27_defer.zig "One Two"
check_it 28_defer2.zig "(Goat) (Cat) (Dog) (Dog) (Goat) (Unknown) done."
check_it 29_errdefer.zig "Getting number...got 5. Getting number...failed!"
check_it 30_switch.zig "ZIG?"
check_it 31_switch2.zig "ZIG!"
check_it 32_unreachable.zig "1 2 3 9 8 7"
check_it 33_iferror.zig "2<4. 3<4. 4=4. 5>4. 6>4." "Seriously, what's the deal with fours?"
check_it 34_quiz4.zig "my_num=42" "Can you make this work?"
check_it 35_enums.zig "1 2 3 9 8 7" "This problem seems familiar..."
check_it 36_enums2.zig "#0000ff" "I'm feeling blue about this."
check_it 37_structs.zig "Your wizard has 90 health and 25 gold."
check_it 38_structs2.zig "Character 2 - G:10 H:100 XP:20"
check_it 39_pointers.zig "num1: 5, num2: 5" "Pointers aren't so bad."
check_it 40_pointers2.zig "a: 12, b: 12"
check_it 41_pointers3.zig "foo=6, bar=11"
check_it 42_pointers4.zig "num: 5, more_nums: 1 1 5 1"
check_it 43_pointers5.zig "Wizard (G:10 H:100 XP:20)"
check_it 44_quiz5.zig "Elephant A. Elephant B. Elephant C." "Oh no! We forgot Elephant B!"
# optional vals (simple scalar)
# optional fields (elephant tail - no longer need circular)
# super-simple struct method
# use struct method for elephant tails
# quiz: add elephant trunk (like tail)!
echo
echo " __ __ _ "
echo " \ \ / __ _ _ _| | "
echo " \ V / _' | | | | | "
echo " | | (_| | |_| |_| "
echo " |_|\__,_|\__, (_) "
echo " |___/ "
echo
echo "You've completed all of the Ziglings exercises!"
echo " (That have been written so far.)"
echo