memoize various read-only arrays

[sean-]

Description

Cache array operations to reduce memory utilization and CPU time associated with heap management. faker is now no longer in the hot path when generating random data.

[jaswdr]

LGTM, this is an excellent catch and improvement.

[jaswdr]

Congratulations for your first contribution 🎉 I'll follow up on this topic and start to check benchmarks on generators performance.

[jaswdr]

Changes released in v1.18.0

[sean-]

There's some other low-hanging fruit in the following two that I expect to take a pass at, too, if they end up being critical (vs just inefficient):

• faker/internet.go

  Lines 49 to 50 in 614e97a

  	name = strings.ToLower(name)
  	name = validEmailOnlyValidCharacters.ReplaceAllString(name, "_")

• faker/internet.go

  Lines 61 to 64 in 614e97a

  	user = strings.Replace(user, "{{firstName}}", i.transformIntoValidEmailName(p.FirstName()), 1)
  	// {{lastName}}
  	user = strings.Replace(user, "{{lastName}}", i.transformIntoValidEmailName(p.LastName()), 1)