Basic Retrieval

Basic retrieval functions are used to retrieve a single element from the injector.

Get

Get returns the element and an error. Use this when you need to handle errors explicitly.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
package main

import (
	"database/sql"
	"log"

	"github.com/wrapped-owls/goremy-di/remy"
)

func main() {
	db, err := remy.Get[*sql.DB](injector)
	if err != nil {
		log.Fatal(err)
	}
	// Use db...
}

MustGet

MustGet returns the element and panics if an error occurs. Use when you’re certain the element exists.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
package main

import (
	"database/sql"

	"github.com/wrapped-owls/goremy-di/remy"
)

func main() {
	db := remy.MustGet[*sql.DB](injector)
	// Use db... (will panic if not found)
}

MaybeGet

MaybeGet returns the element or the zero value if an error occurs. Use when you want to ignore errors gracefully.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
package main

import (
	"database/sql"

	"github.com/wrapped-owls/goremy-di/remy"
)

func main() {
	db := remy.MaybeGet[*sql.DB](injector)
	// db will be nil if not found, but no error handling needed
	if db != nil {
		// Use db...
	}
}

Retrieving Multiple Matches

When you expect multiple registered elements to match the same requested type (for example, several implementations of an interface while duck typing is enabled), use the GetAll family:

GetAll[T] returns ([]T, error)
MustGetAll[T] panics on error
MaybeGetAll[T] returns an empty slice on error

1
2
3
4
5
6
7
// Example: retrieve all encoders implementing the same interface
type Encoder interface{ Encode([]byte) []byte }

encoders := remy.MustGetAll[Encoder](injector)
for _, enc := range encoders {
	_ = enc.Encode([]byte("payload"))
}

If you only need one specific implementation among many, prefer registering and retrieving with tags to disambiguate.