ECE326 PROGRAMMING LANGUAGES Lecture 1 : Course Introduction Kuei (Jack) Sun ECE University of Toronto Fall 2019 Course Instructor Kuei (Jack) Sun Contact Information Use Piazza Send me (Kuei Sun) a private post Not “Instructors”, otherwise the TAs will also see it http://piazza.com/utoronto.ca/fall2019/ece326 Sign up to the course to get access Office: PRA371 (office hours upon request only) Research Interests Systems programming, software optimization, etc. 2 Course Information Course Website http://fs.csl.toronto.edu/~sunk/ece326.html Lecture notes, tutorial slides, assignment handouts Quercus Grade posting, course evaluation, lab group sign-up! Piazza Course announcement, course discussion Assignment discussion Lab TAs will read and answer relevant posts periodically 3 Course Information No required textbook Exam questions will come from lectures, tutorials, and assignments See course website for suggested textbooks Lab sessions Get face-to-face help from a TA with your assignments Tutorials Cover supplementary materials not in lectures Go through sample problems that may appear on exams 4 Volunteer Notetakers Help your peers Improve your own notetaking skills Receive Certificate of Recognition Information: https://www.studentlife.utoronto.ca/as/note-taking Registration: https://clockwork.studentlife.utoronto.ca/custom/misc/home.aspx Notetakers needed for lectures and tutorials 5 Background Programming Languages A formal language consisting of a instructions to implement algorithms and perform tasks on computers Thousands exist, more being made Programming Paradigms A way to categorize programming languages by features Execution model Code organization Style and syntax …etc 6 Course Outline Imperative Programming Writing instructions and commands (APS105) Object- Oriented Programming Objects interacting with one another (ECE244) Metaprogramming Writing code that generates more code (CSC324) Concurrent Programming Multiple tasks overlapping in their executions (ECE344, CSC367) Functional Programming Programming in the style of evaluating mathematical functions (CSC324) 7 Course Objective Learn different ways of writing computer programs Law of the instrument “To the man who only has a hammer, everything he encounters begins to look like a nail.” – Abraham Maslow One style may work better than others for a given problem E.g. recursion vs. iteration Analyze programming languages and their features Semantic: more expressive power Syntactic: easier to read/write Optimization: improves performance and efficiency 8 Syntactic Sugar Example: Java For Loop String[] fruits = { “Apple”, “Banana”, “Strawberry” }; for (int i = 0; i < fruits.length; i++) { system.out.println(fruits[i]); } For-Each Loop for (String f : fruits) { system.out.println(f); } Same bytecode generated, but easier to read 9 Compiler Optimization Example: C restrict keyword Informs compiler that a pointer has no alias void add2(int * a, int * b, int * restrict c) { *a += *c; // normally, *c must be reloaded because a may // point to same address as c, which means that // *c could change after “*a += *c” is executed *b += *c; } Compiler can thus be more aggressive in optimizing this function 10 Course Objective Learn implementations of language features Cost-benefit analysis E.g. automatic memory management Avoids bugs associated with manual memory management Requires garbage collection Learn programming languages that matters Popularity – large community of active developers Easy to find help Easy to find libraries or packages Easy to find jobs 11 Popularity By job posting Java: 65,986 jobs Mainly used by web application developers Python: 61,818 jobs Known for high productivity JavaScript: 38,018 jobs The de facto language for modern browsers C++: 36,798 jobs Favored by game developers, large application software, …etc. C#, PHP, Perl… Source: https://www.codingdojo.com/blog/the-7-most-in-demand-programming-languages-of-2019 12 Popularity By contribution on GitHub JavaScript Java Python PHP C++ C#, TypeScript, Shell, C, Ruby, …etc Correlates well with popularity by job postings Source: https://github.blog/2018-11-15-state-of-the-octoverse-top-programming-languages/ 13 Popularity By Google search trends JavaScript Python Java Go Google’s programming language Aims to simplify programming in multicore, networking environment Elixir Ruby, Kotlin, TypeScript, Scala, Clojure, ..etc. Source: https://codeburst.io/10-top-programming-languages-in-2019-for-developers-a2921798d652 14 Popularity By growth in community Kotlin HCL TypeScript PowerShell Rust CMake Go Python, Groovy, SQLPL Source: https://github.blog/2018-11-15-state-of-the-octoverse-top-programming-languages/ 15 Lab Assignments 4 Assignments 3 Programming languages C++11 A newer version of C++ compared to what’s learned in ECE244 Python 3 Extremely popular high-level programming language Rust Fairly new systems programming language Focuses on performance and safety Requires you to really understand your own code 16 Lab Assignments 1. Easy Blackjack Play the game automatically 2. Optimal strategy calculator Play Blackjack optimally 3. Object-relational mapping Seamless integration of objects with a relational database 4. Concurrent Database Implement a fast toy database 17 Lab Assignments Expect significant efforts involved You will need to spend time outside of lab hours Learn new programming languages Apply new programming techniques Require time to design and implement your program Require lots of time for debugging and performance improvement Groups of 2 Sign up for a group on Quercus Required for you to gain access to Git repository Allows you to work on a common code base Also used to submit your assignment 18 Lab Information You may go to any of the lab sessions for TA help Lab times and location posted on course website After hour support (on Piazza) Your peers! Teaching Assistants Assignment 1: Xue (Chloe) Geng Assignment 2: Wenjun (Wendy) Qiu Assignment 3: Szu-Chieh (Jeffrey) Fang Assignment 4: Jemin Andrew Choi Me I won’t answer unless the problem is with the assignment 19 Assignment Grading Automated Tester Runs a set of tests Correctness Performance Gives you a mark on your solution WYSIWYG Mark you get from tester is what you expect for the assignment Assignment Submission Follow lab instructions You may submit multiple times – do not submit last minute! 20 Assignment Policy No deadline extensions Failure to submit on time will result in zero marks There’s two of you per group You are given 3 to 5 weeks per assignment start early, don’t procrastinate! Make sure you submit something for partial marks Plagiarism and Cheating Severe penalty Grade reduction to suspension from University Talk to me if you feel overwhelmed 21 Grading Scheme Midterm: 25% October 29th, 4pm to 5:30pm, EXE320 Final: 45% Assignments: 26% 5%, 6%, 7%, 8%, respectively Tutorial Quizzes: 4% 12 tutorials, 12 quizzes Only need to complete 10/12 quizzes for full marks 22 Next Lecture “Classifications of Programming Languages” Instructor: Kuei (Jack) Sun Course Website: http://fs.csl.toronto.edu/~sunk/ece326.html Piazza Discussion: http://piazza.com/utoronto.ca/fall2019/ece326 23 ECE326 PROGRAMMING LANGUAGES Lecture 2 : Comparison of Programming Languages Kuei (Jack) Sun ECE University of Toronto Fall 2019 Programming Languages Thousands of them Goal How to describe a programming language in one line? Buzzwords! Intended audience (i.e. programmers) Performance Expressiveness Dominant style, syntax, or feature etc… 2 By Intended Users General-purpose language Used by various application domains E.g. C++, Python, Java, …etc Domain-specific language (DSL) Specialized use E.g. Galaxy Designed for StarCraft 2’s map editor by Blizzard Entertainment No clear boundary Perl and SQL used to be considered DSL 3 By Support Standard Library Provides frequently used functionality E.g. libstdc++ Build tool Automates creation of executables from source code E.g. GNU make, Apache Ant Compiler must support separate compilation Package Manager E.g. Python pip Tool that automates installing, upgrading, and removing software and/or data in a consistent manner 4 By Implementation Compiled Source code compiled to machine code (executable) Runs faster/more efficient Requires recompilation for any source code change Can impact productivity, especially for large software Portability concerns Compiler must support all target architectures Bugs may be introduced when porting to another architecture E.g. long in C is architecture dependent – can break developer assumption long long – at least 64 bits In couple of years: long long long for 128-bits? 5 By Implementation Interpreted Usually associated with high-level languages Interpreter directly executes instructions of a program Usually done in one of the following way: 1. Parse as you go Syntax errors not caught until line is (about to be) executed E.g. Bash script 2. Translate to some intermediate representation first E.g. Python Limited form of optimization possible 6 By Implementation Mixture of both Virtual machine Source code compiled to bytecode Run bytecode on virtual machine Virtual machine can run on any hardware platform (portability) E.g. Java Virtual Machine (JVM) Just -in-time compilation Compile while program is running! Compile when “needed” E.g. if compilation