Making a Go program 70% faster with a one character change • Harry Marr

Programmer and engineering manager working at GitHub. Co-founded Dependabot, and helped build Monzo and GoCardless.

If you read the title and thought “well, you were probably just doing something silly beforehand”, you’re right! But what is programming if not an exercise in making silly mistakes? Tracking down silly mistakes is where all the fun is to be had! I’ll also state the usual benchmarking caveat up front: the 1.7x speedup was measured while running the program on my data on my computer, so take that number with a big old pinch of salt. What does the program do? codeowners is a Go program that prints out the owners for each file in a repository according to a set of rules defined in a GitHub CODEOWN

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