coalesce

Coalesce built-in Go types.

motivation

Go doesn't have a null coalescing operator, so this package brings the capability to return the first non-nil value in a list, pretty much inspired by the COALESCE() SQL function.

install

go get github.com/romanodesouza/coalesce

example

package main

import (
	"github.com/romanodesouza/coalesce"
)

// OptionalParams holds values that are not required.
type OptionalParams struct {
	Int    *int
	String *string
}

// Params represents the "final" structure to be used.
type Params struct {
	Int    int
	String string
}

// DefaultParams holds the optional params fallback values.
var DefaultParams = Params{Int: 10, String: "default string"}

func main() {
	// OptionalParams could be given by user input containing non-required field values.
	optional := OptionalParams{}
	// The coalesce functions are handy when initializing structs:
	params := Params{
		Int:    *coalesce.Int(optional.Int, &DefaultParams.Int),
		String: *coalesce.String(optional.String, &DefaultParams.String),
	}
}