Rework the example a little bit, add some tokens to match

sample.amo

@@ -2,9 +2,9 @@
 
 type SimpleType
 	= MyVariant1
-	| MyVariant2 Integer[u32]
-	| MyVariant3 Integer[1..20]
-	| MyVariant4 Integer String
+	| MyVariant2 Int[u32]
+	| MyVariant3 Int[1..20]
+	| MyVariant4 Int String
 
 /* Multiline
    Comment! */
@@ -15,23 +15,24 @@ type Option val
 
 struct MyStruct =
 	.field1 : SimpleType
-	.field2 : Integer
+	.field2 : Int
 
 trait Eq needs
-	add : Self, Self -> Self
+	.add : Self, Self -> Self
 
 trait Functor[a, b] on Self _ needs
-	map : (a -> b), Self a -> Self b
-	pure : a -> Self a
+	.map : (a -> b), Self a -> Self b
+	.pure : a -> Self a
 
 type ComplexType[a, b : Functor]
 	= Left a
 	| Right b
 
 impl Functor on Option _:
-	map mapper union = if union is
+	.map mapper union = if union is
 		Some val -> Some (mapper val)
 		None -> None
+	.pure elem = Some elem
 
 magnitude : Int, Int -> Int
 magnitude x y = sqrt (x * x) (y * y)
@@ -43,7 +44,7 @@ soundeffect type =
 	else
 		"bop!"
 
-destructure : MyStruct -> Option Integer
+destructure : MyStruct -> Option Int
 destructure s =
 	if s is
 		MyStruct
@@ -60,10 +61,23 @@ destructure s =
 				None
 		_ -> None
 
-destructure_type : SimpleType -> Integer
+destructure_type : SimpleType -> Int
 destructure_type t =
 	if t is
 		MyVariant1 -> 0
 		MyVariant2 x -> x * x
 		MyVariant3 x -> x /2
 		MyVariant4 x _ -> x
+
+simple_tuple : (Int, Int)
+simple_tuple = (1, 2)
+
+magnitude_plus_ten : Int, Int -> Int
+magnitude_plus_ten x y =
+	let magnitude =
+		let x_squared = x * x
+		let y_squared = y * y
+		in sqrt (x + y)
+	in
+		let magnitude_plus_5 = magnitude + 5
+		in magnitude_plus_5 + 5

src/token.rs

@@ -90,6 +90,19 @@ pub enum Token {
 	#[token("on")]
 	On,
 
+	/// the `let` keyword
+	///
+	/// Allows binding a value to an immutable variable that can be used multiple times
+	#[token("let")]
+	Let,
+
+	/// the `in` keyword
+	///
+	/// Used to seperate a series of `let` bindings from the expression they're being used
+	/// in.
+	#[token("in")]
+	In,
+
 	/// An `->` arrow
 	///
 	/// Used as part of function type annotations as well as in the cases of If-Is blocks
@@ -186,6 +199,18 @@ pub enum Token {
 	#[token("..")]
 	RangeOp,
 
+	/// A `.` period
+	///
+	/// For getting fields of structs
+	#[token(".")]
+	Dot,
+
+	/// A `,` comma
+	///
+	/// The age-old and timeless delineator
+	#[token(",")]
+	Comma,
+
 	/// A newline NOT followed by whitespace
 	///
 	/// This means that the following tokens are at the start of a line.  For example