Merge pull request #53 from pedropark99/revision-4

Add revision for Chapters 4, 5 and 6

.gitignore

@@ -17,3 +17,5 @@ foo.txt
 *.aux
 *.log
 *.toc
+
+Chapters/15-vectors_files/

Chapters/01-memory.qmd

@@ -394,7 +394,7 @@ object you declare is stored:
 One key aspect about Zig, is that there are "no hidden-memory allocations" in Zig.
 What that really means, is that "no allocations happen behind your back in the standard library" [@zigguide].
 
-This is a known problem, specially in C++. Because in C++, there are some operators that do allocate
+This is a known problem, especially in C++. Because in C++, there are some operators that do allocate
 memory behind the scene, and there is no way for you to known that, until you actually read the
 source code of these operators, and find the memory allocation calls.
 Many programmers find this behaviour annoying and hard to keep track of.

Chapters/01-zig-weird.qmd

@@ -920,7 +920,7 @@ try stdout.print("{any}\n", .{c});
 ### Runtime versus compile-time known length in slices
 
 We are going to talk a lot about the differences between compile-time known
-and runtime known across this book, specially at @sec-compile-time.
+and runtime known across this book, especially at @sec-compile-time.
 But the basic idea is that a thing is compile-time known, when we know
 everything (the value, the attributes and the characteristics) about this thing at compile-time.
 In contrast, a runtime known thing is when the exact value of a thing is calculated only at runtime.
@@ -1065,7 +1065,7 @@ const object: []const u8 = "A string object";
 Zig always assumes that this sequence of bytes is UTF-8 encoded. This might not be true for every
 sequence of bytes you have it, but is not really Zig's job to fix the encoding of your strings
 (you can use [`iconv`](https://www.gnu.org/software/libiconv/)[^libiconv] for that).
-Today, most of the text in our modern world, specially on the web, should be UTF-8 encoded.
+Today, most of the text in our modern world, especially on the web, should be UTF-8 encoded.
 So if your string literal is not UTF-8 encoded, then, you will likely
 have problems in Zig.
 
@@ -1418,7 +1418,7 @@ the data produced by all of this technology becomes one of the most important
 (and also, one of the most dangerous) assets that we have.
 
 This is probably the main reason why modern low-level programming languages
-have been giving great attention to safety, specially memory safety, because
+have been giving great attention to safety, especially memory safety, because
 memory corruption is still the main target for hackers to exploit.
 The reality is that we don't have an easy solution for this problem.
 For now, we only have techniques and strategies that mitigates these
@@ -1453,7 +1453,7 @@ pattern.
 
 In contrast, the Zig language is not a memory safe language by default.
 There are some memory safety features that you get for free in Zig,
-specially in arrays and pointer objects. But there are other tools
+especially in arrays and pointer objects. But there are other tools
 offered by the language, that are not used by default.
 In other words, the `zig` compiler does not obligates you to use such tools.
 
@@ -1482,7 +1482,7 @@ We already learned a lot about Zig's syntax, and also, some pretty technical
 details about it. Just as a quick recap:
 
 - We talked about how functions are written in Zig at @sec-root-file and @sec-main-file.
-- How to create new objects/identifiers at @sec-root-file and specially at @sec-assignments.
+- How to create new objects/identifiers at @sec-root-file and especially at @sec-assignments.
 - How strings work in Zig at @sec-zig-strings.
 - How to use arrays and slices at @sec-arrays.
 - How to import functionality from other Zig modules at @sec-root-file.

Chapters/02-debugging.qmd

@@ -18,17 +18,17 @@ knitr::opts_chunk$set(
 
 # Debugging Zig applications
 
-Being able to debug your programs is essential to any programmer who wants to
+Being able to debug your applications is essential for any programmer who wants to
 do serious programming in any language. That is why, in this chapter, we are going to talk about the
 available strategies and tools to debug applications written in Zig.
 
 
-## Printing debugging
+## Print debugging
 
 We begin with the classic and battle-tested *print debugging* strategy.
 The key advantage that debugging offers you is *visibility*.
 With *print statements* you can easily see what results and objects
-that are being generated within your functions.
+are being produced by your application.
 
 That is the essence of *print debugging*. Is to use
 print expressions to see the values that are being generated by your program,
@@ -37,20 +37,20 @@ is behaving.
 
 Many programmers often resort to the print functions in Zig, such as the `stdout.print()`,
 or, the `std.debug.print()`, to get a better understanding of their programs.
-This is an known and old strategy that is very simple and effective, and it is better known within
+This is a known and old strategy that is very simple and effective, and it is better known within
 the programming community as *print debugging*.
-In Zig, you can either print information to the `stdout` or `stderr` streams of your system.
+In Zig, you can print information to the `stdout` or `stderr` streams of your system.
 
 Let's begin with `stdout`. First, you
 need to get access to the `stdout`, by calling the `getStdOut()` method, from
-the Zig standard library. This method returns a *file descriptor* object,
+the Zig Standard Library. This method returns a *file descriptor* object,
 and, through this object you can read/write to the `stdout`.
 I recommend you to check out all methods available in this object, by [checking the page in
 the Zig Standard Library Official Reference for the type `File`](https://ziglang.org/documentation/master/std/#std.fs.File)[^zig-fiile-reference].
 
 [^zig-fiile-reference]: <https://ziglang.org/documentation/master/std/#std.fs.File>.
 
-For our purpose here, which is to write something to the `stdout`, specially to debug our
+For our purpose here, which is to write something to the `stdout`, especially to debug our
 program, I recommend you to use the `writer()` method, which gives your a *writer* object.
 This *writer* object offers some helper methods to write stuff into the file descriptor object
 that represents the `stdout` stream. In special, the `print()` method.
@@ -64,7 +64,7 @@ in the second argument, you provide a list of values (or objects) that you want
 into your template message.
 
 Ideally, the template string in the first argument should contain some format specifier.
-Each format specifier is matched to a value (or object) that you listed in the second argument.
+Each format specifier is matched to a value (or object) that you have listed in the second argument.
 So, if you provided 5 different objects in the second argument, then, the template string
 should contain 5 format specifiers, one for each object provided.
 
@@ -80,7 +80,7 @@ Here is a quick list of the most used format specifiers:
 - `x`: for printing hexadecimal values.
 - `any`: use any compatible format specifier (i.e. it automatically selects a format specifier for you).
 
-The code example below, gives you an example of use of this `print()` method
+The code example below gives you an example of use of this `print()` method
 with the `d` format specifier.
 
 ```{zig}
@@ -122,11 +122,23 @@ pub fn main() !void {
 Result: 50
 ```
 
+You could also achieve the exact same result by getting a file descriptor object to `stderr`,
+then, creating a *writer* object to `stderr`, then, using the `print()` method of this
+*writer* object, like in the example below:
+
+```{zig}
+#| eval: false
+const std = @import("std");
+const stderr = std.io.getStdErr().writer();
+// some more lines ...
+_ = try stderr.print("Result: {d}", .{result});
+```
+
 
 
 ## Debugging through debuggers
 
-Although *print debugging* is a valid and very useful strategy,
+Although *print debugging* being a valid and very useful strategy,
 most programmers prefer to use a debugger to debug their programs.
 Since Zig is a low-level language, you can use either GDB (GNU Debugger),
 or LLDB (LLVM Project Debugger) as your debugger.
@@ -136,28 +148,28 @@ You choose the debugger of your preference, and you work with it.
 In this book, I will use LLDB as my debugger on the examples.
 
 
-### Compile your source code in Debug mode {#sec-compile-debug-mode}
+### Compile your source code in debug mode {#sec-compile-debug-mode}
 
 In order to debug your program through a debugger, you must compile
-your source code in Debug mode. Because when you compile your
-source code in other modes (such as Release), the compiler usually
+your source code in `Debug` mode. Because when you compile your
+source code in other modes (such as `Release`), the compiler usually
 strips out some essential information that is used by the debugger
 to read and track your program, like PDB (*Program Database*) files.
 
-By compiling your source code in Debug mode, you ensure that the debugger
+By compiling your source code in `Debug` mode, you ensure that the debugger
 will find the necessary information in your program to debug it.
-By default, the compiler uses the Debug mode. Having this in mind,
-when you compile your program with the `build-exe`
-command (that we exposed at @sec-compile-code), if you don't specify an explicit mode through the `-O` command-line [^oargument]
-argument, then, the compiler will compile your code in Debug mode.
+By default, the compiler uses the `Debug` mode when compiling your code.
+Having this in mind, when you compile your program with the `build-exe`
+command (which was described at @sec-compile-code), if you don't specify
+an explicit mode through the `-O` command-line [^oargument]
+argument, then, the compiler will compile your code in `Debug` mode.
 
 [^oargument]: See <https://ziglang.org/documentation/master/#Debug>.
 
 
 ### Let's debug a program
 
-As an example, let's debug some Zig code, and demonstrate
-how can we use LLDB to navigate and check the following
+As an example, let's use LLDB to navigate and investigate the following
 piece of Zig code:
 
 ```{zig}
@@ -182,7 +194,7 @@ pub fn main() !void {
 There is nothing wrong with this program. But it is
 a good start for us. First, we need to compile
 this program with the `zig build-exe` command.
-For this example, suppose that I compiled the above
+For this example, suppose that I have compiled the above
 Zig code into a binary executable called `add_program`.
 
 ```bash
@@ -226,12 +238,12 @@ Process 8654 stopped
    14  	}
 ```
 
-I can start to navigate through the code, and investigating the variables
-that are being generated. If you not familiar with the commands
+I can start navigating through the code, and checking the objects
+that are being generated. If you are not familiar with the commands
 available in LLDB, I recommend you to read the official documentation
 of the project[^lldb].
-You can also look for cheat sheets. Which quickly describes all commands
-available for you, and, as a result, are also good resources for you[^lldb-quick-list].
+You can also look for cheat sheets, which quickly describes all commands
+available for you[^lldb-quick-list].
 
 [^lldb]: <https://lldb.llvm.org/>
 [^lldb-quick-list]: <https://gist.github.com/ryanchang/a2f738f0c3cc6fbd71fa>.
@@ -271,11 +283,11 @@ Process 4798 stopped
 
 Now, on the next line of code, we are executing the `add_and_increment()` function once again.
 Why not step inside this function? Shall we? We can do that, by executing the `s` LLDB command.
-Notice in the example below that, after executing this command, we entered inside the context of the
+Notice in the example below that, after executing this command, we have entered into the context of the
 `add_and_increment()` function.
 
-Also notice in the example below that, I walked two more lines in the functions body, then,
-I executed the `frame variable` LLDB command, to see at once, the value stored in each of the variables
+Also notice in the example below that, I have walked two more lines in the function's body, then,
+I execute the `frame variable` LLDB command, to see at once, the value stored in each of the variables
 that were created inside the current scope.
 
 You can see in the output below that, the object `sum` stores the value `\f`,
@@ -337,3 +349,4 @@ pub fn main() !void {
 
 This function is similar to the `type()` built-in function from Python,
 or, the `typeof` operator in Javascript.
+

Chapters/03-structs.qmd

@@ -18,7 +18,7 @@ knitr::opts_chunk$set(
 # Control flow, structs, modules and types
 
 We have discussed a lot of Zig's syntax in the last chapter,
-specially at @sec-root-file and @sec-main-file.
+especially at @sec-root-file and @sec-main-file.
 But we still need to discuss some other very important
 elements of the language. Elements that you will use constantly on your day-to-day
 routine.

Chapters/03-unittests.qmd

@@ -106,7 +106,7 @@ All 1 tests passed.
 One of the advantages of Zig is that it offers great tools
 that hep us, programmers, to avoid (but also detect) memory problems, such as
 memory leaks and double-frees. The `defer` keyword
-is specially helpful in this regard.
+is especially helpful in this regard.
 
 When developing your
 source code, you, the programmer, is responsible for making
@@ -245,7 +245,7 @@ All 1 tests passed.
 In Zig, there are some different ways you can test for an equality.
 You already saw that we can use `expect()` with the logical operator `==`
 to essentially reproduce an equality test. But we also have
-some helper functions that you should know about, specially
+some helper functions that you should know about, especially
 `expectEqual()`, `expectEqualSlices()` and `expectEqualStrings()`.
 
 

Chapters/04-http-server.qmd

@@ -983,7 +983,7 @@ into our `main.zig` module, then, I add the function calls to `send_200()`
 and `send_404()`.
 
 Notice that I'm using if statements to decide which "response function" to call,
-based specially on the URI present in the HTTP Request. If the user asked for
+based especially on the URI present in the HTTP Request. If the user asked for
 a content (or a document) that is not present in our server, we should respond
 with a 404 status code. But since we have just a simple HTTP server, with no
 real documents to send, we can just check if the URI is the root path (`/`)