lessons: formatting, some nits, mostly: fmt -l10000000

web/_posts/2011-05-01-lesson.textile

@@ -5,9 +5,7 @@ layout: post
 desc: Values, functions, classes, methods, inheritance, try-catch-finally. Expression-oriented programming
 ---
 
-h1. Lesson 1
-
-Today we'll cover:
+This lesson covers:
 * values
 * expressions
 * functions
@@ -18,14 +16,11 @@ Today we'll cover:
 
 h2. About this class
 
-The first few weeks will cover basic syntax and concepts. Then we'll start
-to open it up with more exercises.
+The first few weeks will cover basic syntax and concepts.  Then we'll start to open it up with more exercises.
 
-Some examples will be given as if written in the interpreter, others
-as if written in a source file.
+Some examples will be given as if written in the interpreter, others as if written in a source file.
 
-Having an interpreter available makes it easy to explore a problem
-space.
+Having an interpreter available makes it easy to explore a problem space.
 
 
 h2. Why Scala?
@@ -50,8 +45,7 @@ h2. How Scala?
 
 h2. Think Scala
 
-Scala is not just a nicer Java. You should learn it with a fresh mind,
-you will get more out of these classes.
+Scala is not just a nicer Java.  You should learn it with a fresh mind, you will get more out of these classes.
 
 h2. Start the Interpreter
 
@@ -73,11 +67,9 @@ scala> 1 + 1
 res0: Int = 2
 </pre>
 
-res0 is an automatically created value name given by the interpreter
-to the result of your expression. It has the type Int and contains the
-Integer 2.
+res0 is an automatically created value name given by the interpreter to the result of your expression.  It has the type Int and contains the Integer 2.
 
-Everything in Scala is an expression.
+(Almost) everything in Scala is an expression.
 
 h2. Values
 
@@ -97,9 +89,7 @@ scala> def addOne(m: Int): Int = m + 1
 addOne: (m: Int)Int
 </pre>
 
-In Scala, you need to specify the type signature for function
-parameters. The interpreter happily repeats the type signature back to
-you.
+In Scala, you need to specify the type signature for function parameters.  The interpreter happily repeats the type signature back to you.
 
 <pre>
 scala> val three = addOne(2)
@@ -151,16 +141,11 @@ scala> calc.brand
 res2: String = "HP"
 </pre>
 
-
-Contained are examples are defining methods with def and fields with
-val. methods are just functions that can access the state of the class.
+Contained are examples are defining methods with def and fields with val.  methods are just functions that can access the state of the class.
 
 h4. Constructor
 
-Constructors aren't special methods, they are the code outside of
-method definitions in your class. Let's extend our Calculator example
-to take a constructor argument and use it to initialize internal
-state.
+Constructors aren't special methods, they are the code outside of method definitions in your class.  Let's extend our Calculator example to take a constructor argument and use it to initialize internal state.
 
 <pre>
 class Calculator(brand: String) {
@@ -201,9 +186,7 @@ class EvenMoreScientificCalculator(brand: String) extends ScientificCalculator(b
 
 h3. Expressions
 
-Our BasicCalculator example gave an example of how Scala is
-expression-oriented. The value color was bound based on an if/else
-expression.
+Our BasicCalculator example gave an example of how Scala is expression-oriented.  The value color was bound based on an if/else expression.
 
 h3. try-catch-finally
 
@@ -234,7 +217,6 @@ val result: Int = try {
 }
 </pre>
 
-This is not an example of excellent programming style, just an example
-of expressions in action. Better would be to re-throw.
+This is not an example of excellent programming style, just an example of expressions in action.  Better would be to re-throw.
 
 Finally will be called after any exception has been handled.

web/_posts/2011-05-02-lesson.textile

@@ -5,9 +5,7 @@ layout: post
 desc: Case classes, objects, packages, apply, update, Functions are Objects (uniform access principle), pattern matching.
 ---
 
-h1. Lesson 2
-
-Today we'll cover:
+This lesson covers:
 * apply
 * objects
 * case classes
@@ -63,12 +61,9 @@ scala> Timer.currentCount
 res0: Long = 1
 </pre>
 
+Classes and Objects can have the same name.  The object is called a 'Companion Object'.  We commonly use Companion Objects for Factories.
 
-Classes and Objects can have the same name. The object is called a
-'Companion Object'. We commonly use Companion Objects for Factories.
-
-Here is a trivial example that only serves to remove the need to use
-'new' to create an instance.
+Here is a trivial example that only serves to remove the need to use 'new' to create an instance.
 
 <pre>
 class Bar(foo: String)
@@ -80,8 +75,7 @@ object Bar {
 
 h3. Case Classes
 
-case classes are used to conveniently store data with a class. You can
-construct them without using new.
+case classes are used to conveniently store data with a class.  You can construct them without using new.
 
 <pre>
 scala> case class Bottle(color: String)
@@ -96,8 +90,7 @@ res1: String = Blue
 
 You will often see them used in Twitter code as record types.
 
-case classes automatically have equality and nice toString methods
-based on the constructor arguments.
+case classes automatically have equality and nice toString methods based on the constructor arguments.
 
 <pre>
 scala> val blue = Bottle("Blue")
@@ -113,17 +106,13 @@ scala> blue.equals(blu)
 res1: Boolean = true
 </pre>
 
-
 case classes can have methods.
 
 h3. Functions are Objects
 
-In Scala, we talk about object-functional programming often. What does
-that mean?
+In Scala, we talk about object-functional programming often.  What does that mean?
 
-We saw earlier that giving your class an apply method you can use it
-like it's a function. Let's look in the other direction. Let's define
-a simple function and see what's under the hood.
+We saw earlier that giving your class an apply method you can use it like it's a function.  Let's look in the other direction.  Let's define a simple function and see what's under the hood.
 
 <pre>
 def addOne(x: Int) = x + 1
@@ -139,8 +128,7 @@ scala> addOne _
 res1: (Int) => Int = <function1>
 </pre>
 
-Hmm, what is a function1? A Function1 is simply a trait for a function
-that takes one argument.
+Hmm, what is a function1?  A Function1 is simply a trait for a function that takes one argument.
 
 <pre>
 scala> val addOne = new Function1[Int, Int] {
@@ -152,20 +140,11 @@ scala> addOne(1)
 res2: Int = 2
 </pre>
 
-There is Function1 through 22. Why 22? It's an arbitrary magic
-number. I've never needed a function with more than 22 arguments so it
-seems to work out.
+There is Function1 through 22.  Why 22?  It's an arbitrary magic number.  I've never needed a function with more than 22 arguments so it seems to work out.
 
-The syntatic sugar of apply helps unify the duality of object and
-functional programming. You can pass classes around and use them as
-functions and functions are just instances of classes under the
-covers.
-
-Does this mean that everytime you define a method in your class,
-you're actually getting an instance of Function*? No, methods in
-classes are methods. methods defined standalone in the repl are
-Function* instances.
+The syntatic sugar of apply helps unify the duality of object and functional programming.  You can pass classes around and use them as functions and functions are just instances of classes under the covers.
 
+Does this mean that everytime you define a method in your class, you're actually getting an instance of Function*?  No, methods in classes are methods.  methods defined standalone in the repl are Function* instances.
 
 h3. Packages
 
@@ -177,8 +156,7 @@ package com.twitter.example
 
 at the top of a file will declare everything in the file to be in that package.
 
-Values and functions cannot be outside of a class or object. Objects
-are a useful tool for organizing static functions.
+Values and functions cannot be outside of a class or object.  Objects are a useful tool for organizing static functions.
 
 <pre>
 package com.twitter.example
@@ -205,10 +183,7 @@ scala> object colorHolder {
 defined module colorHolder
 </pre>
 
-This gives you a small hint that the designers of Scala designed
-objects to be part of Scala's module system.
-
-
+This gives you a small hint that the designers of Scala designed objects to be part of Scala's module system.
 
 h3. Pattern Matching
 
@@ -238,8 +213,7 @@ times match {
 
 Notice how we captured the value in the variable 'i'.
 
-case classes are designed to be used with pattern matching. Let's
-expand on our bottle example from earlier.
+case classes are designed to be used with pattern matching.  Let's expand on our bottle example from earlier.
 
 <pre>
 case class Bottle(color: String, ounces: Int)

web/_posts/2011-05-03-lesson.textile

@@ -5,9 +5,7 @@ layout: post
 desc: Lists, Maps, functional combinators (map, foreach, filter, zip, folds)
 ---
 
-h1. Lesson 3
-
-Today we'll cover:
+This lesson covers:
 * Lists
 * Maps
 * Sets
@@ -171,8 +169,7 @@ res0: scala.collection.immutable.Set[Int] = Set(1, 2)
 
 h3. Seq
 
-Sequences have a defined order, they are Lists under the covers but
-many APIs will use the more generic Seq as their return type.
+Sequences have a defined order, they are Lists under the covers but many APIs will use the more generic Seq as their return type.
 
 <pre>
 scala> Seq(1, 1, 2)
@@ -189,8 +186,7 @@ scala> val hostPort = ("localhost", 80)
 hostPort: (java.lang.String, Int) = (localhost, 80)
 </pre>
 
-Unlike case classes, they don't have named accessors, instead they
-have accessors that are named by their position (1-based).
+Unlike case classes, they don't have named accessors, instead they have accessors that are named by their position (1-based).
 
 <pre>
 scala> hostPort._1
@@ -211,16 +207,13 @@ hostPort match {
 
 h2. Functional Combinators
 
-This fancy name is giving to a standard set of functions that can be
-applied to Lists and Maps.
+This fancy name is giving to a standard set of functions that can be applied to Lists and Maps.
 
-They are called combinators because they are meant to be combined. the
-output of one function is often suitable as the input for another.
+They are called combinators because they are meant to be combined.  the output of one function is often suitable as the input for another.
 
 h4. map
 
-Evaluates a function over each element in the list, returning a list
-with the same number of elements.
+Evaluates a function over each element in the list, returning a list with the same number of elements.
 
 <pre>
 scala> numbers.map((i: Int) => i * 2)
@@ -257,9 +250,7 @@ doubled: Unit = ()
 
 h4. filter
 
-removes any elements where the function you pass in evaluates to
-false. Functions that return a Boolean are often called predicate
-functions.
+removes any elements where the function you pass in evaluates to false.  Functions that return a Boolean are often called predicate functions.
 
 <pre>
 scala> numbers.filter((i: Int) => i % 2 == 0)
@@ -285,8 +276,7 @@ res0: List[(Int, java.lang.String)] = List((1,a), (2,b), (3,c))
 
 h4. partition
 
-partition splits a list based on where it falls with respect to a
-predicate function.
+partition splits a list based on where it falls with respect to a predicate function.
 
 <pre>
 scala> List(1, 2, 3, 4, 5, 6, 7, 8, 9, 10).partition((i: Int) => i > 5)
@@ -311,8 +301,7 @@ scala> numbers.drop(5)
 res0: List[Int] = List(6, 7, 8, 9, 10)
 </pre>
 
-dropWhile removes elements that don't match a predicate function. Here
-we can re-implement drop.
+dropWhile removes elements that don't match a predicate function.  Here we can re-implement drop.
 
 <pre>
 scala> numbers.dropWhile((i: Int) => i < 6)
@@ -368,13 +357,11 @@ res0: Int = 55
 
 h4. Generalized functional combinators
 
-Now we've learned a grab-bag of functions for working with
-collections.
+Now we've learned a grab-bag of functions for working with collections.
 
 What we'd like is to be able to write our own functional combinators.
 
-Interestingly, every functional combinator shown above can be written
-on top of fold. Let's see some examples.
+Interestingly, every functional combinator shown above can be written on top of fold.  Let's see some examples.
 
 <pre>
 def ourMap(numbers: List[Int], fn: Int => Int): List[Int] = {
@@ -391,9 +378,7 @@ Why <tt>List[Int]()</tt>? Scala wasn't smart enough to realize that you wanted a
 
 h3. Map?
 
-All of the functional combinators shown work on Maps, too. Maps can be
-thought of as a list of pairs so the functions you write work on a
-pair of the keys and values in the Map.
+All of the functional combinators shown work on Maps, too.  Maps can be thought of as a list of pairs so the functions you write work on a pair of the keys and values in the Map.
 
 <pre>
 scala> val extensions = Map("steve" -> 100, "bob" -> 101, "joe" -> 201)

web/_posts/2011-05-04-lesson.textile

@@ -6,11 +6,9 @@ desc: More functions! PartialFunctions, more Pattern Matching
 ---
 
 
-h1. Lesson 4
-
 h2. Advanced Pattern Matching and Functional Composition
 
-Today we'll cover
+This lesson covers:
 
 * Functions (again)
 ** compose
@@ -143,14 +141,11 @@ scala> stevej match {
          case User("stevej", _, _) => println("it's stevej")
 </pre>
 
-But what if we don't want User to be a case class? How can we make
-User interact nicely with pattern matching without changing the User
-class?
+But what if we don't want User to be a case class?  How can we make User interact nicely with pattern matching without changing the User class?
 
 Use the extractor method: unapply.
 
-Make a companion object with an unapply method. The unapply should
-return an Option with a Tuple that matches your class' constructor.
+Make a companion object with an unapply method.  The unapply should return an Option with a Tuple that matches your class' constructor.
 
 <pre>
 object User {
@@ -185,14 +180,11 @@ They are multiple PartialFunctions composed together.
 
 h3. Understanding PartialFunction
 
-A function closes over an entire domain. In other words, a function
-defined as (Int) => String takes any Int and returns a String.
+A function closes over an entire domain.  In other words, a function defined as (Int) => String takes any Int and returns a String.
 
-A Partial Function is only partially closed over a domain. A Partial
-Function (Int) => String might not accept every Int.
+A Partial Function is only partially closed over a domain.  A Partial Function (Int) => String might not accept every Int.
 
-isDefinedAt is a method on PartialFunction that can be used to
-determine if the PartialFunction will accept a given argument.
+isDefinedAt is a method on PartialFunction that can be used to determine if the PartialFunction will accept a given argument.
 
 <pre>
 scala> val one: PartialFunction[Int, String] = { case 1 => "one" }