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Keynote. Professor Steven G. Johnson | JuliaCon 2019

The Julia Programming Language · 17.8K views · 2019-07-24 · 52:40

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Overview

Steven G. Johnson, MIT professor and FFTW co-author, gives a JuliaCon 2019 keynote on metaprogramming and staged programming in Julia, showing how it enables high-performance numerical code and when not to use macros.

On Hacker News

Cited for showing how Julia's metaprogramming can beat C and Fortran, along with sound advice not to overuse it.

Recommended by 2 HN people across 2 months · HN mentions 2019–2022

Topics

Python, Ruby & scripting languagesProgramming language designSoftware performance & optimization
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juliametaprogramminghigh performance computingmacrosnumerical computing

What people said

eigenspace · 2019-08 · Strong recommendation

If anyone is looking for video recommendations to get started: here’s a couple that I thought were great and should be interesting and approachable to just about anyone. Steven G. Johnson’s keynote address. It’s longer format but really interesting, informative, entertaining and well delivered. The main topic is metaprogramming. [VIDEO] Stefan Karpinski’s talk on the unreasonable effectiveness of multiple dispatch. He discusses the fact that Julia has such dramatic code re-use and sharing between libraries and he discusses some reasons why he thinks multiple dispatch is uniquely able to offer this. [LINK]

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ViralBShah · 2020-10 · Recommendation

You can write slow programs in all languages. There are many cases where Julia's language features enable higher performance than in comparable C libraries. Have a look at Steve Johnson's keynote from JuliaCon 2019: [VIDEO]

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mwattsun · 2022-01 · Reference

When I first started writing asm code, it was accepted to write self-modifying code (programmatically create new code, then jmp to it.) Then I discovered and was told it was a bad idea. So that's how I view Lisp macros - creating code on the fly and executing it. When I was studying this issue, I came across femtolisp, which is a standalone Lisp by the author of Julia, Jeff Bezanson. Julia has metaprogramming so I wanted to look at it. In this video [1] Professor Steve G. Johnson explains metaprogramming (around 10 min mark) and says "most of the time, don't do metaprogramming." He points out in the base Julia there are 36,798 methods, but only 138 macros and 14 generated functions (.04% of the code), so I have the impression it is still frowned upon. [1] [VIDEO]

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Sources

Video by The Julia Programming Language, played through YouTube.

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