Lecture 26

Programming Languages and Paradigms

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engineering v. programming

What’s the best language?

• There isn’t one
• Different languages for different projects
• Languages come and go pretty fast
• “We use about 10 languages a year, but they change from year to year”
• You want to learn to program
• You want to learn programming paradigms/styles
• Functional (declarative)
• Imperative
• Object-oriented
• We’ll do all three of these this quarter
• You want to learn to learn languages
• No matter what we teach you, 80% of you won’t be using at your jobs

The Racket language

We started the quarter using Racket’s Intermediate Student Language and then moved to the Advanced Student Language. These are dialects of Racket!

• Low barrier to entry (for those with and without programming experience)
• More powerful than more conventional languages
• Specifically designed to use to learn how to program
• Racket itself is a language-oriented language. You can use it to build your own programming languages for specialized content domains.
• Multi-paradigmatic – functional…imperative…object-oriented
• VideoLang is an example of a domain-specific language
• Racket's parser can be modified to emulate any kind of syntax

Currently Popular Text-based Languages

• Python (CS 150) - popular in machine learning and data science
• C and C++ (CS 211 and upper-level compilers courses)
• JavaScript - popular in web development
• Java - popular in security focused applications
• Rust - this is the hot new thing
• Perl - popular in networking contexts
• Go - popular in video/audio editing
• Swift - iOS/Mac development

Most popular programming languages over time

How do you choose what language to use?

• Performance
• What is the most common operation you'll be doing?
• What sort of hardware will you run on?
• How crucial is performance and will it be distributed?
• Talent
• Programmers are by far the most limited resource in software engineering.
• Is there an existing talent pool?
• Will you have to have training?
• Domain-specificity
• What sort of work are you doing?
• Will it need to be used by non-software engineers?
• Can you take advantage of domain-knowledge to improve the development process?

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• Security - Has the programming language been verified to be secure? What about your 3rd party libraries?

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• Licensing - Is it free to use? Is it extensible? What about libraries? What's the attitude of the community?

Learning new languages

https://doc.rust-lang.org/rust-by-example/index.html

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StackOverflow

Domain/context specific languages

Bifrost (Maya)

Max (from Cycling 74)

NetLogo (designed at Northwestern)