CSC 347 - Concepts of Programming Languages

Course Overview

Instructor: Stefan Mitsch

Programming Languages

• 1970: assembly, FORTRAN, COBOL, Lisp
• 1980: C, Pascal, BASIC, ML, Smalltalk
• 1990: C++, Perl, Objective C, Erlang
• 2000: Java, JavaScript, Python, Ruby, Lua
• 2005: C#
• 2010: Scala, F#, Clojure, Go
• 2015: Rust, Swift, Kotlin, Elm, Elixir, TypeScript, PureScript
• 2020: ReasonML, Crystal, Pony, Zig
• Many more!

Programming Languages

• Programming languages keep popping up
• You will have to keep learning new languages
• And keep up with changes to current languages
  • Java 8 and C++ 11 added Lambda expressions (nested, anonymous functions)
• Lots of common concepts!

Learning Objectives

Learn PLs more easily by recognizing concepts

• "it has while loops"
• "it has closures"
• "it has list comprehensions"
• "it has dynamic dispatch"

• Deeper understanding of PL concepts / paradigms
• Impact of PL on program development, modularity, correctness, runtime efficiency, etc.

Non-Goals

• Learn a PL similar to one you already know
• Instead, learn concepts to facilitate quick assimilation of new PLs as they appear

• Learn an IDE
• Instead, become familiar with a range of tools and build systems

Course Overview

What are different ways of expressing computations?

• Programming paradigms and styles:
  • functional vs object-oriented
  • mutability vs immutability
  • iteration vs recursion
  • pattern matching vs visitor design pattern

• Runtime Storage: lexical and dynamic scope; stack layout; how to support inheritance and dynamic dispatch; nested structures (functions or objects); garbage collection
• Static Analysis: dynamic vs static type checking; subtyping; parametric polymorphism

Course Approach

• Hands on: write many programs and experiments

• Scala as main language:
  • carefully designed multi-paradigm language
  • textbook explains PL concepts in context
• Also bits of: C, C++, C#, Java, JavaScript...
  • ... Kotlin, Swift, Rust, Scheme, Haskell
  • chosen as exemplars of concepts

Discussion Forum

• On D2L
• Use appropriate language

Asking Questions

• For non-personal messages use D2L
  • "I think there is a mistake with grading of Question 3 of Homework 2." - direct message/email to instructor
  • "I cannot run program foo. I have tried running it from the command line on OS X. See below for a transcript of what I typed and the error message I received. Could you please help?" - ask in D2L discussion forum

Asking Questions

• Include name, student number, and class in messages directly to the instructor
• Include enough context to answer your question:
  • "program foo doesn't work." - bad
  • "program foo fails with output pasted below" - good
  • "program foo fails with input and output pasted below" - better
  • "program foo fails with input and output pasted below; using OS X; I have run extra commands to show current working directory, the version of foo in use, and other relevant information" - best

Course Syllabus

• Review the Syllabus linked from the course homepage
• Programming in Scala, First Edition is available for free online
• Get Programming in Scala 5th edition
• Earlier editions use a different version of Scala than class; you can use them but may need to look up new syntax