Optimize

To run:

go build && ./debugging && open http://localhost:8080/

Before optimizing do a benchmark first

$ go test -bench=.

goos: darwin
goarch: amd64
pkg: github.com/MarcGrol/go-training/examples/debugging
BenchmarkMyHandler-8   	  100000	     13946 ns/op
PASS
ok  	github.com/MarcGrol/go-training/examples/debugging	1.557s

Make your fix

Do not recreate regexp upon each request

Run benchmark again

$ go test -bench=.

goos: darwin
goarch: amd64
pkg: github.com/MarcGrol/go-training/examples/debugging
BenchmarkMyHandler-8   	  500000	      2699 ns/op
PASS
ok  	github.com/MarcGrol/go-training/examples/debugging	1.394s

Has improved enough?

Or need to optimize even more?

// fmt.Fprintf(w, "Hallo %s van nexushealth", match[0][1]) // if strings.HasSuffix(path, "@nexushealth.be") { name := strings.TrimSuffix(path, "@nexushealth.be")