Conform UUID to Stringer interface

[quinn]

Is your feature request related to a problem? Please describe.
I use sqlc, updated sql_package use pgx instead of previous version which used github.com/google/uuid. My code generally works as-is, except for some cases where I would pass an ID to something that expects a "stringer":

func (t T) String() string

For example, this makes it easy to tag logs with ID's:

logger = logger.With(zap.Stringer("thing", thing.ID))

Describe the solution you'd like
Add String method to UUID.

Describe alternatives you've considered

Additional context
here's the implementation from google's package:

func (uuid UUID) String() string {
	var buf [36]byte
	encodeHex(buf[:], uuid)
	return string(buf[:])
}

func encodeHex(dst []byte, uuid UUID) {
	hex.Encode(dst, uuid[:4])
	dst[8] = '-'
	hex.Encode(dst[9:13], uuid[4:6])
	dst[13] = '-'
	hex.Encode(dst[14:18], uuid[6:8])
	dst[18] = '-'
	hex.Encode(dst[19:23], uuid[8:10])
	dst[23] = '-'
	hex.Encode(dst[24:], uuid[10:])
}

I can make a PR if that would help expedite this.

[jackc]

I guess we could add it, but pgtype.UUID isn't intended to be anything more that the minimum necessary to transfer UUIDs. I actually recommend using a 3rd party UUID type. Both the google one and the gofrs one work out of the box with pgx and there are extension packages for both that completely integrate them into pgx.

[quinn]

@jackc yep makes sense. thats what I ended up doing, the first example in the sqlc docs is for doing exactly this:

https://docs.sqlc.dev/en/stable/howto/overrides.html

[andradei]

@jackc Is this documented in this package? There's a vague documentation on sqlc as linked by @quinn but it would be great to have this mentioned in the docs since pgtype.UUID does not have good API for users of the driver and google/uuid and others are much better on higher levels like web apps.

[jackc]

@andradei The extension libraries are listed in the README. https://github.com/jackc/pgx/?tab=readme-ov-file#adapters-for-3rd-party-types. It's the same situation for decimal/numeric. pgx has a type whose sole purpose is to transfer values, but you really probably want to use shopspring/decimal.

[grachevko]

#2145

It's not looking as a big deal especially we already have encode UUID function.
Looks worst to install 3rd party just for unexported simple function

[andradei]

@grachevko Finally! That's very helpful.