CPS 530 Study Guide - Summer 2018, Comprehensive Midterm Notes - Type System, Type Inference, Smalltalk
12 Oct 2018
School
Department
Course
Professor
CPS 530
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Jan’s Somewhat Half-Assed Guide to Mason’s fucking wildride.
No seriously, i’d rather trust United to fly me somewhere than him to teach.
I’d rather get in a car with Paul Walker than him teaching this class.
I’d even trust Bill Cosby to buy me a fucking drink more than this guy. Anyways:
Notes about general comparative programming languages:
• Smalltalk is an object-oriented, dynamically typed, reflective programming language. What
does this mean?
◦ Everything in smalltalk is an object.
◦ Dynamically typed, you don’t have to declare a type in small talk
• Haskell is a purelyfunctional programming language, with non-strict semantics and strong static
typing.
◦ Functional means, basically, it treats its evaluations like math, data is immutable
◦ Haskell is lazy, meaning (non-strict semantics) it isn’t going to evaluate something if it isn’t
directly part of a function call.
◦ Also has strong typing. This means that if the types are off, haskell will fail to compile
◦ Literally the biggest sticking point of Haskell is monads
▪ These are blocks of computation, kinda like functions, but they NEED parameters,
▪ According to Mason, Java doesn’t have Monads. Literally Google Java Monads and all
you’ll see is how Java 8 has fucking monads.
◦ Haskell has similar semantics to the language Miranda. Do with that what you will.
• Elixir is functional and concurrent.
◦ Again, functional, shit in this language is immutable. Why the FUCK you would make a
game with constant changing states like snakes-and-ladders is fucking beyond me.
◦ Concurrent means that it’s the type of language that allows several things happening at
once, concurrently, which is why Elixir is used for things like chatrooms.
• Rust is functional and imperative. Well it combines the two to be honest
◦ Yes things are immutable, but the language is also procedural, meaning code does depend
on state.
Smalltalk Notes
• Smalltalk was created as the language to underpin the “new world of computing exemplified by
human computer symbiosis”
o No I’m not making that fucking up. Now this language has been relegated to a bunch of
old dudes.
▪ You know, its kind of poetic irony. I’ll let you all figure that out on your own
o Allowable characters (remember this language is old af)
▪ A-Z, a-z, 0-9, .+/*~<>@%|&?
▪ Blank,tab,cr,ff,if
o Variables!
▪ Must be declared before use
▪ Shared vars begin with uppercase
▪ Local vars begin with lowercase
▪ Reserved names are nil, true, false, self, super, and Smalltalk
find more resources at oneclass.com
find more resources at oneclass.com
• Variable scope:
o Global
o Local to a method
o Local to a black
• Sample Transcript
o Transcript clear. //clears transcript window
o Transcript show: ‘Hello World’. //output string in transcript
• Assignment
o | x y |
o x := 5 //assignment
o x := y := 6 //compound assignment
o x := Object new. //bind to allocated instance
• Conversion
o | x |
o X := 3.99 asInteger.
• Blocks
o |x y z|
o x := [y :=1. z:=2.]. x value /////simple block assignment
o X := [:argOne :argTwo | argOne, ‘ and ‘, argTwo.]. ////block with argument passing
o Transcript show: (x value: ‘First’ value: ‘Second’); cr.
• Method calls:
o Unary methods are messages with no arguments
o Binary methods
o Keyword methods are messages with selectors including colons
• Conditional Statements
o | x |
o X > 10 ifTrue: [aBlock]
▪ Note: Yes you can nest them
• X > 10 ifTrue: [x > 5 ifTrue: [aBlock]].
• Man I wish I didn’t have to hate this language
• Iterations
o | x y |
o X := 4. Y := 1.
o [x > 0] whileTrue: [x := x – 1. Y:=y *2]
o 1 to: x do: [:a |y := y * 2]
• Ordered Collections
o | b x y sum max|
o X := OrderedCollection with: 4 with: 3 with: 2 with: 1. //creates a collection with up to 4
elements
o X := OrderedCollection new. ////allocate it
o X add: 3; add: 2; add: 1; add: 4; yourself. ///add elements to collection
o Y := addFirst: 5.
• Return
o ^
find more resources at oneclass.com
find more resources at oneclass.com
