go-utils

Go Utils

Functional programming utilities for Go 1.21+ designed to complement stdlib's slices, maps, and cmp packages.

Why Go Utils?

Complementary to stdlib: Use slices.Index, slices.Contains, slices.Clone for basic operations. Use go-utils for functional patterns (Map, Filter, Reduce), LINQ-style operations (GroupBy, Partition), and utilities not in stdlib.

Type-safe with generics: All functions use Go 1.21+ generics with appropriate constraints for compile-time type safety.

Immutable by default: Functions don't mutate inputs. Operations return new values.

100% test coverage: Every function is comprehensively tested.

Installation

go get -u github.com/Goldziher/go-utils

Quick Examples

Functional Slice Operations

import "github.com/Goldziher/go-utils/sliceutils"

numbers := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

// Chain functional operations
evens := sliceutils.Filter(numbers, func(v, i int, s []int) bool {
    return v%2 == 0
})

doubled := sliceutils.Map(evens, func(v, i int, s []int) int {
    return v * 2
})

sum := sliceutils.Reduce(doubled, func(acc, v, i int, s []int) int {
    return acc + v
}, 0)
// Result: sum = 60 (2+4+6+8+10 doubled = 4+8+12+16+20 = 60)

LINQ-Style Operations

type User struct {
    Name string
    Age  int
    Role string
}

users := []User{
    {"Alice", 30, "admin"},
    {"Bob", 25, "user"},
    {"Charlie", 30, "user"},
}

// Group by age
byAge := sliceutils.GroupBy(users, func(u User) int { return u.Age })
// Result: map[int][]User{25: [{Bob 25 user}], 30: [{Alice 30 admin}, {Charlie 30 user}]}

// Partition by predicate
admins, regularUsers := sliceutils.Partition(users, func(u User) bool {
    return u.Role == "admin"
})

// Get distinct ages
ages := sliceutils.DistinctBy(users, func(u User) int { return u.Age })

Map Transformations

import "github.com/Goldziher/go-utils/maputils"

data := map[string]int{"apple": 5, "banana": 3, "cherry": 8}

// Extract keys and values
keys := maputils.Keys(data)     // []string{"apple", "banana", "cherry"}
values := maputils.Values(data) // []int{5, 3, 8}

// Filter map entries
filtered := maputils.Filter(data, func(k string, v int) bool {
    return v > 4
})
// Result: map[string]int{"apple": 5, "cherry": 8}

Type-Safe String Conversion

import "github.com/Goldziher/go-utils/stringutils"

// Stringify any type with options
hex := stringutils.Stringify(42, stringutils.Options{Base: 16})  // "2a"
float := stringutils.Stringify(3.14159, stringutils.Options{Precision: 2})  // "3.14"

// Stringify complex types
m := map[string]int{"a": 1, "b": 2}
str := stringutils.Stringify(m)  // "{a: 1, b: 2}"

Business Date Calculations

import "github.com/Goldziher/go-utils/dateutils"

// Add business days (skips weekends)
future := dateutils.AddBusinessDays(time.Now(), 5)

// Check date range overlap
overlaps := dateutils.Overlap(start1, end1, start2, end2)

// Calculate age
age := dateutils.Age(birthdate)

Packages

Documentation

Full documentation available at goldziher.github.io/go-utils

API reference at pkg.go.dev/github.com/Goldziher/go-utils

Contributing

Contributions are welcome! Please read the Contributing Guide before submitting PRs.

License

MIT License - see LICENSE for details.

Author

Na'aman Hirschfeld