Guava Multimaps.index equivalent for golang?

Question

I'm relatively new to go, and I'm looking for a rough equivalent (library or implementation) of guava multimap's index method. It works as follow It should do the following: Given a slice of structs, construct a map from the common value to arrays of entries that share that value. For example: Repetition struct { ID int Days int Category string } reps := []Repetition{ Repetition{ID: 1, Day: 0, Category: "strength"}, Repetition{ID: 2, Day: 0, Category: "aerobic"} Repetition{ID: 3, Day: 1, Category: "strength"} Repetition{ID: 4, Day: 1, Category: "aerobic"} } result = indexByDay(reps) where result is: map[int][]Repetition{ 0: []Repetition{Repetition{ID: 1, Day: 0, Category: "strength"}, Repetition{ID: 2, Day: 0, Category: "aerobic"}}, 1: []Repetition{Repetition{ID: 3, Day: 1, Category: "strength"}, Repetition{ID: 4, Day: 1, Category: "aerobic"}} } The question is whether there are any built in or existing libraries that have methods like indexByDay (somehow generic enough for to be library code perhaps?) Apologies if my map literal is hilariously incorrect. I'm still new to the language. JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

Eh this turned out to not be that hard: func group(reps []lifting.Repetition) map[int][]Repetition { m := make(map[civil.Date][]lifting.Repetition) for _, rep := range reps { value, present := m[rep.Day] if !present { m[rep.Day] = []lifting.Repetition{rep} } else { m[rep.Day] = append(value, rep) } } return m }