Update book to add new example
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				| @ -247,6 +247,8 @@ calls, literals, or if-expressions. Types of supported expressions include: | ||||
| - **Function calls**, to invoke a predefined function with given parameters | ||||
| - **Associated function calls**, to invoke a predefined function on a certain | ||||
|   *associated type* with given parameters. | ||||
|   - **Accessing function calls**, a shorthand to call associated function calls | ||||
|     which have `&self` or `&mut self` as their first parameter. | ||||
| - **Block-expressions**, which can return a value to the higher-level expression | ||||
|   if they have a statement with a soft-return. Otherwise they return void. | ||||
| - **If-expressions**, which can execute one of two expressions depending on the | ||||
| @ -263,7 +265,7 @@ In formal grammar: | ||||
|     <array> | <struct> | | ||||
|     <indexing> | <accessing> | | ||||
|     <binary-exp> | <unary-exp> | | ||||
|     <function-call> | <assoc-function-call> | ||||
|     <function-call> | <accessing-function-call> | <assoc-function-call> | ||||
|     <block> | <if-expr> | <cast> | | ||||
|     ( "(" <expression> ")" ) | ||||
| 
 | ||||
| @ -278,6 +280,7 @@ In formal grammar: | ||||
| <binary-exp> :: <expression> <binop> <expression> | ||||
| <unary-exp> :: <unary> <expression> | ||||
| <function-call> :: <expression> "(" [ <expression> ( "," <expression> )* ] ")" | ||||
| <accessing-function-call> :: <accessing> "(" [ <expression> ( "," <expression> )* ] ")" | ||||
| <assoc-function-call> :: <type> "::" <function-call> | ||||
| <if-expr> :: "if" <expression> <expression> [ "else" <expression> ] | ||||
| <cast> :: <expression> "as" <type> | ||||
| @ -296,6 +299,7 @@ test.first // Accessing | ||||
| !bool_value // Unary | ||||
| func(value, 14) // Function call | ||||
| Test::get_field(&test); // Associated function call | ||||
| test.get_field(); // Same, but using a the dot-form shorthand | ||||
| if varname {} else {} // If-expression | ||||
| value as u32 // cast | ||||
| (value + 2) // Binop within parenthesis | ||||
|  | ||||
| @ -22,6 +22,7 @@ or simply casting the value (e.g. `5 as u32`). | ||||
| ## Table of Contents: | ||||
| - [Hello World](#hello-world) | ||||
| - [Borrowing and Pointers](#borrowing-and-pointers) | ||||
| - [Harder Hello World](#harder-hello-world) | ||||
| 
 | ||||
| ### Hello World | ||||
| 
 | ||||
| @ -120,3 +121,73 @@ This example will always return `17`. Notice also, how a **mutable** borrow was | ||||
| passed to `mutate`-function. While borrows do not always need to be mutable, | ||||
| this example would not work without the `mut`-keyword. Try it out for yourself | ||||
| to see why! | ||||
| 
 | ||||
| ### Harder Hello World | ||||
| 
 | ||||
| A little bit harder example to the previous hello world would be | ||||
| `hello_world_harder.reid` from [examples](../examples/hello_world_harder.reid) | ||||
| 
 | ||||
| ```rust | ||||
| import std::print; | ||||
| import std::String; | ||||
| 
 | ||||
| fn main() { | ||||
|     let mut test = String::from("hello"); | ||||
| 
 | ||||
|     test.push(String::from(" world: ")); | ||||
|     test.push_num(175); | ||||
|      | ||||
|     print(test); | ||||
| 
 | ||||
|     test.free(); | ||||
|     return; | ||||
| } | ||||
| ``` | ||||
| 
 | ||||
| Let's go through this again line-by-line | ||||
| 
 | ||||
| ```rust | ||||
| import std::print; | ||||
| import std::String; | ||||
| ``` | ||||
| 
 | ||||
| At the start are the standard imports, like in the original Hello World, but | ||||
| notice that instead of importing just functions we import the type `String` as | ||||
| well. When importing types, not only are the type imported, but also any binary | ||||
| functions or associated functions related to it with it. | ||||
| 
 | ||||
| ```rust | ||||
|     let mut test = String::from("hello"); | ||||
| ``` | ||||
| 
 | ||||
| Next we create the initial string, just like in our original example, but this | ||||
| time the message is not complete. We also use an associated function to create | ||||
| the string instead one of the now-deprecated global functions. | ||||
| 
 | ||||
| ```rust | ||||
|     test.push(String::from(" world: ")); | ||||
|     test.push_num(175); | ||||
| ``` | ||||
| 
 | ||||
| After that we edit the message by first pushing ` world: ` to it, and also | ||||
| appending the number `175` at the end of it. For both of these operations we are | ||||
| again using associated functions, but in a different short-hand syntax. | ||||
| 
 | ||||
| These two lines would be actually equivalent to the above ones: | ||||
| ```rust | ||||
|     String::push(&mut test, String::from(" world: ")); | ||||
|     String::push_num(&mut test, 175); | ||||
| ``` | ||||
| 
 | ||||
| ---- | ||||
| 
 | ||||
| ```rust | ||||
| 
 | ||||
|     print(test); | ||||
| 
 | ||||
|     test.free(); | ||||
|     return; | ||||
| ``` | ||||
| 
 | ||||
| After that we simply print the string, and free up the string (again with an | ||||
| associated function) before returning. Nothing special there! | ||||
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