add Compiler diagram

[sjkelly]

This is inspired by the diagram presented by Lionel Zoubritzky
in his 2018 JuliaCon talk.
This gives a visual overview of what is happening in the compiler.

[sjkelly]

I've cleaned up the design up a bit for symmetry and legibility. Feedback is appreciated.

[Seelengrab]

The green on orange text is a bit hard to make out, and the "Specialize" from "Method Dispatch" to "IR" could do with a different layout/position - it looks a bit odd that it's the only text crossing a colored box boundary.

[sjkelly]

Thanks for the great feedback @Seelengrab! I tweaked the colors and alignment a bit. I agree yellows are tough on the eyes!

[Seelengrab]

Thank you! Yeah, that's easier to follow.

[cormullion]

the black lines might struggle for visibility on a dark background (eg dark mode)... Here's a suggested edit that should work on any background. Changing the black elements to a midtone color would also work...

[sjkelly]

Thanks for the feedback @cormullion, good catch!

[KristofferC]

Note that CI seems to fail here.

[inkydragon]

Note that CI seems to fail here.

LaTeX does not have good support for SVG.
So there is an error when compiling PDFs.

• https://tex.stackexchange.com/questions/2099/how-to-include-svg-diagrams-in-latex

A workaround is to keep both SVG and PNG formatted images, and to refer to the PNG images in the md document.

This is an upstream issue that requires Documenter.jl to improve the SVG support of the LaTeX backend.

[ViralBShah]

Simplest to just check in a png as well

[sjkelly]

I've opted to commit both the PNG and SVG. It was done in Google Draw, so there is unfortunately no other lossless format we can use for posterity.

[fredrikekre]

There is also https://github.com/JuliaDocs/DocumenterMermaid.jl for things like this now, but will probably also fail in PDF output.