[](https://app.circleci.com/pipelines/github/leodido/go-urn) [](https://codecov.io/gh/leodido/go-urn) [](https://godoc.org/github.com/leodido/go-urn)
**A parser for URNs**.
> As seen on [RFC 2141](https://datatracker.ietf.org/doc/html/rfc2141), [RFC 7643](https://datatracker.ietf.org/doc/html/rfc7643#section-10), and on [RFC 8141](https://datatracker.ietf.org/doc/html/rfc8141).
[API documentation](https://godoc.org/github.com/leodido/go-urn).
Starting with version 1.3 this library also supports [RFC 7643 SCIM URNs](https://datatracker.ietf.org/doc/html/rfc7643#section-10).
Starting with version 1.4 this library also supports [RFC 8141 URNs (2017)](https://datatracker.ietf.org/doc/html/rfc8141).
## Installation
```
go get github.com/leodido/go-urn
```
## Features
1. RFC 2141 URNs parsing (default)
2. RFC 8141 URNs parsing (supersedes RFC 2141)
3. RFC 7643 SCIM URNs parsing
4. Normalization as per RFCs
5. Lexical equivalence as per RFCs
6. Precise, fine-grained errors
## Performances
This implementation results to be really fast.
Usually below 400 ns on my machine[1](#mymachine).
Notice it also performs, while parsing:
1. fine-grained and informative erroring
2. specific-string normalization
```
ok/00/urn:a:b______________________________________/-10 51372006 109.0 ns/op 275 B/op 3 allocs/op
ok/01/URN:foo:a123,456_____________________________/-10 36024072 160.8 ns/op 296 B/op 6 allocs/op
ok/02/urn:foo:a123%2C456___________________________/-10 31901007 188.4 ns/op 320 B/op 7 allocs/op
ok/03/urn:ietf:params:scim:schemas:core:2.0:User___/-10 22736756 266.6 ns/op 376 B/op 6 allocs/op
ok/04/urn:ietf:params:scim:schemas:extension:enterp/-10 18291859 335.2 ns/op 408 B/op 6 allocs/op
ok/05/urn:ietf:params:scim:schemas:extension:enterp/-10 15283087 379.4 ns/op 440 B/op 6 allocs/op
ok/06/urn:burnout:nss______________________________/-10 39407593 155.1 ns/op 288 B/op 6 allocs/op
ok/07/urn:abcdefghilmnopqrstuvzabcdefghilm:x_______/-10 27832718 211.4 ns/op 307 B/op 4 allocs/op
ok/08/urn:urnurnurn:urn____________________________/-10 33269596 168.1 ns/op 293 B/op 6 allocs/op
ok/09/urn:ciao:!!*_________________________________/-10 41100675 148.8 ns/op 288 B/op 6 allocs/op
ok/10/urn:ciao:=@__________________________________/-10 37214253 149.7 ns/op 284 B/op 6 allocs/op
ok/11/urn:ciao:@!=%2C(xyz)+a,b.*@g=$_'_____________/-10 26534240 229.8 ns/op 336 B/op 7 allocs/op
ok/12/URN:x:abc%1Dz%2F%3az_________________________/-10 28166396 211.8 ns/op 336 B/op 7 allocs/op
no/13/URN:---xxx:x_________________________________/-10 23635159 255.6 ns/op 419 B/op 5 allocs/op
no/14/urn::colon:nss_______________________________/-10 23594779 258.4 ns/op 419 B/op 5 allocs/op
no/15/URN:@,:x_____________________________________/-10 23742535 261.5 ns/op 419 B/op 5 allocs/op
no/16/URN:URN:NSS__________________________________/-10 27432714 223.3 ns/op 371 B/op 5 allocs/op
no/17/urn:UrN:NSS__________________________________/-10 26922117 224.9 ns/op 371 B/op 5 allocs/op
no/18/urn:a:%______________________________________/-10 24926733 224.6 ns/op 371 B/op 5 allocs/op
no/19/urn:urn:NSS__________________________________/-10 27652641 220.7 ns/op 371 B/op 5 allocs/op
```
* [1]: Apple M1 Pro
## Example
For more examples take a look at the [examples file](examples_test.go).
```go
package main
import (
"fmt"
"github.com/leodido/go-urn"
)
func main() {
var uid = "URN:foo:a123,456"
// Parse the input string as a RFC 2141 URN only
u, e := urn.NewMachine().Parse(uid)
if e != nil {
fmt.Errorf(err)
return
}
fmt.Println(u.ID)
fmt.Println(u.SS)
// Output:
// foo
// a123,456
}
```
```go
package main
import (
"fmt"
"github.com/leodido/go-urn"
)
func main() {
var uid = "URN:foo:a123,456"
// Parse the input string as a RFC 2141 URN only
u, ok := urn.Parse([]byte(uid))
if !ok {
panic("error parsing urn")
}
fmt.Println(u.ID)
fmt.Println(u.SS)
// Output:
// foo
// a123,456
}
```
```go
package main
import (
"fmt"
"github.com/leodido/go-urn"
)
func main() {
input := "urn:ietf:params:scim:api:messages:2.0:ListResponse"
// Parsing the input string as a RFC 7643 SCIM URN
u, ok := urn.Parse([]byte(input), urn.WithParsingMode(urn.RFC7643Only))
if !ok {
panic("error parsing urn")
}
fmt.Println(u.IsSCIM())
scim := u.SCIM()
fmt.Println(scim.Type.String())
fmt.Println(scim.Name)
fmt.Println(scim.Other)
// Output:
// true
// api
// messages
// 2.0:ListResponse
}
```