readme version 2

README.md

@@ -28,12 +28,52 @@ You can also declare a constant using the `const` keyword instead.
 ```
 const x int = 9;
 ```
+---
+
+### Scopes
+
+Like in most languages, variables in One are only limited to their scope.
+You can access a variable from a deeper nested scope, but not the opposite:
+
+```
+let x int = 5;
+if 5 > 0 {
+    x = 2;
+}
+```
+
+is valid code, while
+
+```
+if 3 < 10 {
+    let y int = 288;
+}
+y = 10;
+```
+
+isn't valid, as the variable `y` cannot be access outside its scope.
+
+You can also create scopes by wrapping statements in braces. This lets you declare
+variables with the same name in different scopes, for example:
+
+```
+let x int = 3
+{
+    let y real = 5.5;
+    print(y);
+}
+print("y is now undefined again here");
+{
+    let y real = 0.2;
+    print(y);
+}
+```
 
 ---
 
 ### Primitive Types
 
-As of now, One has a total of 4 primitive types: `int`, `real`, `bool` and `string`.
+As of now, One has a total of 4 primitive types: `void`. `int`, `real`, `bool` and `string`.
 There are no methods for types, but you can cast a variable to one of them with this syntax
 
 ```
@@ -44,13 +84,14 @@ let myint int = int(myreal);
 Right now, strings are implemented as direct counterparts to `char*` in C, which is what they
 get translated to during compilation. Comparisons and operations on strings are still work in progress
 and quite buggy, but you are free to use string literals for prints or simple variable declarations with no issues.
+Variables cannot be declared with type `void`.
 
 ---
 
 ### Functions
 
 Functions in One are very similar to what you see in languages such as go.
-You declare a function called `foo` which takes an `int` and returns a `bool` with the following syntax
+You declare a function called `foo` which takes an `int` and returns a `bool` with the following syntax:
 
 ```
 fn foo(myarg int) bool {
@@ -58,7 +99,9 @@ fn foo(myarg int) bool {
 }
 ```
 
-Calling a function looks like this
+If a function is not expected to return anything, the return type must be `void`.
+
+Calling a function looks like this:
 
 ```
 let b bool = foo(9);
@@ -69,8 +112,8 @@ let b bool = foo(9);
 ### Classes
 
 Right now, Classes in One are very similar to C structs. They are declared using the `class` keyword
-followed by the class name and a block with a list of class members. Defining a class User might look
-something like this
+followed by the class name and a block with a list of class members.
+Defining a class User might look something like this:
 
 ```
 class User {
@@ -80,13 +123,16 @@ class User {
 }
 ```
 
-Creating an instance of a class is very simple, just write the name of the class followed by braces and
-a list of initial values for the class members
+Creating an instance of a class is very simple, just write the name of the class
+followed by braces and a list of initial values for the class members.
 
 ```
 let myuser User = User{17, "uan", false}
 ```
 
+Class types can be used anywhere primitive types can, such as function arguments
+or other classes' members.
+
 ---
 
 ### Print
@@ -100,14 +146,14 @@ let x int = 144;
 print(x, 240);
 ```
 
-produces this output
+produces this output:
 
 ```
 144 240
 ```
 
-class-type variables will be printed with special formatting which, if we take the User class and variable
-we defined earlier, will look like this
+class-type variables will be printed with special formatting which, if we takes
+the User class and variable we defined earlier, will look like this.
 
 ```
 User {
@@ -117,4 +163,36 @@ User {
 }
 ```
 
+### Control Flow
+
+Control flow in One is still quite limited, as the `for` keyword has not been implemented yet. `if`, `else` and `elif` statements are fully implemented and are written like this.
+
+```
+let x int = 17;
+
+if x >= 100 {
+    print(x, "is greater than 100");
+} elif x >= 10 {
+    print(x, "is greater than 10"):
+} else {
+    print(x, "is less than 10");
+}
+```
+
+Using parentheses around the condition isn't necessary.
+
+### The main function
+
+It is important that every One program has an entry point called `main`.
+The 'main' function must always return `int` and does not accept any arguments.
+
+```
+fn main() int {
+    print("my code here");
+}
+```
+
+It isn't necessary to explicitly insert a `return` statement in the main function.
+Returning from the main function will exit the program with an exit code equal
+to the returned integer.