Because if I run it from the command-line, it takes 40 seconds before it has precompiled and prepared my project for use. The only way to avoid that wait on every change is to use the REPL, where I only need to wait on the first run.
You don't precompile just because it's run from the commandline though. There must be something missing from your workflow description, or you're somehow misunderstanding what is going on. Since this is a v1.6 blog post: did you try a v1.6 RC?
Maybe precompile is the wrong word, and I should have called it JIT or something else. I don't know.
The point is that running a .jl script that calls my algorithm on a small test case takes 40 seconds to run. If I change the script to run the algorithm more than once on that dataset, all calls after the first complete in less than one second.
Running it with v1.6-rc1, it appears to have improved the running time from 40 seconds to 30. That's pretty good, but still way too slow to enable any kind of workflow that doesn't involve the REPL.
(The 30 and 40 second numbers are very consistent from run to run.)
Outside the REPL, every run is the first run.