[#228] [RF] Improve Cove Coverage. Describe magics

docs/implementation-flow/ch01-s01-dart.tex

@@ -0,0 +1,46 @@
+% Copyright 2023 The terCAD team. All rights reserved.
+% Use of this content is governed by a CC BY-NC-ND 4.0 license that can be found in the LICENSE file.
+
+\subsection{Dart}
+\markboth{Bootcamping}{Dart}
+
+\subsubsection{Overloading operators}
+
+In Dart, "magic methods" are often referred to as "operator overloading" or "special methods." They allow you to define 
+custom behaviors for built-in operations:
+
+\begin{itemize}
+  \item \q{toString} returns a string representation of an object, can be used for a serialization and deserialization 
+  process of an object;
+  \item \q{call} allows an object to be treated as a function;
+  \item \q{hashCode} returns a hash code for an object (to use object as a key for \q{Map} and \q{Set});
+  \item \q{operator==} compares two objects for equality;
+  \item \q{get} and \q{set} -- to override the behavior of getting and setting properties.
+\end{itemize}
+
+\begin{lstlisting}
+class Person {
+  // Required from constructor
+  String name;
+  // Post-initialization
+  late DateTime _createdAt = DateTime.now();
+  // var person = Person('Tom');
+  Person(this.name);
+  // person() // 'Hello from Tom!'
+  String call() => 'Hello from $name!';
+  // person.createdAt = DateTime(2023, 01, 01);
+  set createdAt(DateTime date) => _createdAt = date;
+  // print(person.createdAt); // 2023-01-01 00:00:00
+  DateTime get createdAt => _createdAt;
+  // print(Person('Tom') == Person('Terry')); // false
+  @override
+  bool operator ==(Person other) => other.name == name;
+  // person = Person.fromString('Tom');
+  factory Person.fromString(String name) {
+    return Person(name);
+  }
+  // print(person); // 'Tom'
+  @override
+  String toString() => name;
+}
+\end{lstlisting}

docs/implementation-flow/ch01-s01-dart.tex-dump.tex

@@ -1,3 +1,5 @@
+\subsection{[TBD] Dart}
+
 Question: Flutter check that variable is a function
 
 Answer: In Flutter, you can use the is operator to check if a variable is a function. 

docs/implementation-flow/ch01-s02-flutter.tex

@@ -1,9 +1,8 @@
 % Copyright 2023 The terCAD team. All rights reserved.
 % Use of this content is governed by a CC BY-NC-ND 4.0 license that can be found in the LICENSE file.
 
-\markboth{Bootcamping Flutter}{Bootcamping Flutter}
-
-[TBD]
+\subsection{Flutter}
+\markboth{Bootcamping}{Flutter}
 
 
 \subsubsection{Asserting Functions Definition}
@@ -39,59 +38,6 @@ \subsubsection{Ignoring Function Arguments}
 \end{lstlisting}
 
 
-\subsubsection{Applying Getters and Setters for Class Variables}
-
-By migrating our data structures to class objects it can be used additionally getter and setter for class variables.
-That will help us to cover, as an example, \q{description}-attribute for Budget structures by showing 
-"Spent Amount / Total Budget", and for \q{details}-attribute - "Left Amount".
-
-\begin{lstlisting}
-class MyClass {
-  String _name; // Private variable
-
-  // Getter for name
-  String get name => _name;
-
-  // Setter for name
-  set name(String value) {
-    _name = value;
-  }
-}
-
-void main() {
-  MyClass myObject = MyClass();
-
-  // Using the setter
-  myObject.name = 'John';
-
-  // Using the getter
-  print(myObject.name); // Output: John
-}
-\end{lstlisting}
-
-In the example above, the \q{MyClass}-class has a private variable \q{\_name}. The getter for \q{\_name} is defined 
-using the get keyword, and the setter is defined using the set keyword. The getter returns the value of 
-\q{\_name}, and the setter sets the value of \q{\_name} to the provided value. By using that approach we can control 
-the access to class variables and perform additional logic or validation when getting or setting their values.
-
-One more question, is how to set \q{DateTime.now()} inside a constructor as default value, since, by defining it inside
-the constructor, an error would be taken: The default value of an optional parameter must be constant.
-
-So, to set a default value for a DateTime variable as the current date and time, we can use the \q{DateTime.now()} method 
-during the initialization of the variable.
-
-\begin{lstlisting}
-class MyClass {
-    DateTime _createdAt;
-
-    MyClass({DateTime? createdAt})
-        : _createdAt = createdAt ?? DateTime.now();
-
-    DateTime get createdAt => _createdAt;
-}
-\end{lstlisting}
-
-
 \subsubsection{Using cast to resolve dynamic structures}
 
 Migration our Bills to classes construction has lead to an error on .firstWhere when Account of Budget not found.