iterset

Golang set operations using maps and iterators.

There are many mapset implementations available, but they restrict the values to struct{} or bool. This means slices, maps, and iterators have to be converted to sets. Which besides being inefficient, loses slice ordering and map values. Additionally since sets are not built-in, they realistically will always be secondary types. Even in languages with built-in sets, it is common to call set operations on keys while still retaining data in a map.

So iterset is built around generic maps with any value type. Maps can be casted without copying, and the methods support set operations which integrate with functions in maps and slices. Additionally the methods support iterators for further efficiency. Inspired by Python sets, which allow iterables in methods.

Usage

There are constructors for all common use cases.

• Cast a map
• Unique iterates keys in order
• Collect with default value
• Set from variadic args
• Index retains original position
• Count stores key counts
• IndexBy stores values by key function
• GroupBy stores slices grouped by key function
• Memoize caches function call

Methods support iterators, compatible with slices.Values and maps.Keys.

• Equal
• IsSubset
• IsSuperset
• IsDisjoint
• Union
• Intersect
• Difference
• ReverseDifference
• SymmetricDifference

Scalar operations can be passed as bound methods for functional programming.

• Get
• Contains
• Missing
• Add
• Delete

Installation

No dependencies. Go 1.23 required.

go get github.com/coady/iterset

Tests

go test .