Update types.md

docs/types.md

@@ -1,130 +1,20 @@
 ## Values and Types
 
-Gravity is a dynamically typed language so variables do not have a type, although they refer to a value that does have a type. In Gravity everything is an object (with methods you can call and instance variables you can use). Basic intrinsic types are of class Object, Int, Float, String, Bool, Null, [Class](class.md), [Function](func.md), Fiber, Instance, [List](list.md), [Map](map.md) and Range.
+Gravity is a dynamically typed language so variables do not have a type, although they refer to a value that does have a type. In Gravity everything is an object (with methods you can call and instance variables you can use). Basic intrinsic types are of class [Object](object.md), [Int](int.md), [Float](float.md), [String](string.md), [Bool](bool.md), [Null](null.md), [Class](class.md), [Function](func.md), [Fiber](fiber.md), [Instance](instance.md), [List](list.md), [Map](map.md) and [Range](range.md).
 
-### Object
-Object is the root class of every object inside Gravity. Through the Object class, objects inherit a basic interface to the runtime system and the ability to behave as Gravity objects.
+### Manifest Typing
 
-### Int
-An Int represents a 64 bit (can optionally be compiled as 32 bit) signed number:
+Gravity supports manifest typing, so you can specify which type is associated with an Object with a syntax like:
 ```swift
-	var a = 123;        // decimal
-	var b = 0xFF;       // hexadecimal
-	var c = 0O7777;     // octal
-	var d = 0B0101;     // binary
-
-	var e = Int.random(1, 10) // returns a random int between 1 and 10 inclusive
-
-	var f = 30.radians // returns the result of converting 30 degrees to radians
-	var f = 3.degrees  // returns the result of converting 3 radians to degrees
-```
-
-### Float
-A float represents a 64 bit (can optionally be compiled as 32 bit) floating point number:
-```swift
-	var a = 3.1415;		// float
-	var b = 1.25e2;		// scientific notation
-
-	var f = 30.5.radians // returns the result of converting 30.5 degrees to radians
-	var f = 3.14.degrees // returns the result of converting 3.14 radians to degrees
-```
-
-### String
-Strings are an immutable sequence of characters. String literals can be surrounded with double or single quotes.
-```swift
-	var a = "Hello World";  // double quotes
-	var b = 'Hello World';  // single quotes
-
-	// Strings have also a length property
-	var n = b.length;       // n is now 11
-
-	// Strings also have some built in methods
-	n = b.index("Wor")      // n is now 6.
-
-	n = b.count("l")        // n is now 3.
-	n = b.count("llo")      // n is now 1.
-
-	n = "A".repeat(10)      // n is now "AAAAAAAAAA"
-
-	// upper() and lower() operate on the whole string when 0 arguments are passed
-	n = b.upper()           // n is now "HELLO WORLD"
-	n = b.lower()           // n is now "hello world"
-
-	// upper() and lower() can both take multiple integer arguments
-	n = b.upper(1, -1)     // n is now "HEllo WorlD"
-
-	// split() is the opposite of a list join
-	var string = "Roses are Red, Violets are Blue"
-	var list = string.split(", ")
-	list[0]                // "Roses are Red"
-	list[1]                // "Violets are Blue"
-
-	// Split can also be used to convert a string to a list type so that you can
-	// call list specific methods
-	var string = "abcdefghijklmnpqrstuvwxyz".split('')
-	string.contains("o")   // false
-	string.contains("s")   // true
-
-	// You are also able to edit strings by character...
-	b[0] = "Z"              // b is now "Zello World"
-	b[1] = "abc"            // b is now "Zabco World"
-	b[-7] = "QWERTY"        // b is now "ZabcQWERTYd"
-
-	// and retrieve those characters
-	n = a[6]                // n is now "W"
-	n = a[-7]               // n is now "o"
-	n = a[0...4]            // n is now "Hello"
-	n = a[-5...-1]          // n is now "World"
-	n = a[-5...10]          // n is now "World"
-	n = a[-1...-5]          // n is now "dlroW"
-	
-	// replace o with i
-	var str = "momo"
-	str.replace("o", "i") // returns mimi
-```
-
-### Bool
-The Bool data type can have only two values, they are the literals true and false. A Bool value expresses the validity of a condition (tells whether the condition is true or false).
-```swift
-	var a = true;
-	var b = false;
+var s:String = "Hello World";
+var n:Int = 100;
 ```
 
-### Null
-It indicates the absence of a value. If you call a method that doesn’t return anything and get its returned value, you get null back. The null data type is also used to initialize uninitialized variables with a default value.
+It can also be used in func parameters:
 ```swift
-	class Newton {
-		var mass = 10;
-		var acceleration;
-		func force() {
-			return mass * acceleration;
-		}
-	}
-
-	func f2() {
-		var sir = Newton();
-		// acceleration instance variable has no default value
-		// so it is automatically set to null
-		return sir.force();
-	}
-
-	func f1() {
-		var a;
-		// a is uninitialized so it has a default null value
-		return a;
-	}
+func sum (a:Int, b: Int) {
+	return a + b;
+}
 ```
 
-### Range
-A range is an object that represents a consecutive range of numbers. Syntax for this type has been directly inspired by Swift.
-```swift
-	// a represents a range with values 1,2,3
-	var a = 1...3;
-
-	// b represents a range with values 1,2
-	var b = 1..<3;
-
-	// Ranges have also a conveniente count property
-	var n1 = a.count;	// n1 is now 3
-	var n2 = b.count;	// n2 is now 2
-```
+Manifest typing is currently used in autocompletion feature but I plan to introduce a full static type checking in a future release.