The best replacement for closures is anonymous functions.

The best alternatives to closures are rated as following:
★★★★★  anonymous functions
★★★★  callbacks
★★★  lambdas
★★★  frontals
★  clasps
★  delays
★  objects
  lace closures
  silk base closures
  steri strips

Your alternative for closures is not listed? Suggest!
Speaking about closures, one probably shouldn't forget about weaves.

Other search terms related to closures and their ratings are:
★★★★★ weaves
You have in mind a companion for closures and it is not yet here? Propose!



Google Trends

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closures
anonymous functions
callbacks