Go: Google's Plan9 refugees are staging a breakout

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > Go: Google's Plan9 refugees are staging a breakout

Fluue: Jan 2, 2008

Trying to understand an idiomatic approach to a set-once lazy value for a struct.

I have a simple struct:

code:

type MyObject struct {
	ID              uint32 `db:"id"`
	Name            string `db:"name"`
	shiny           *bool
	types           []ObjectType
}

//
func (o *MyObject) IsShiny() bool {
	// TODO: implement randomness
	return o.shiny
}

I'm initializing and hydrating instances of MyObject from data I retrieve in a database and there are often multiple instances that I construct and return to the caller. The shiny field is determined by a random dice roll and is only set once for the lifetime of the struct.

Should I:
1. Pass in an instance of a seeded *rand.Rand() to IsShiny and only calculate it if o.shiny == nil
2. Create a constructor that accepts *rand.Rand() and do the dice roll during construction

My goal is to be able to test the IsSiny function and make sure the `shiny` field can't be changed after it's set.

edit: also, the dice roll does not need to be perfectly random

Fluue fucked around with this message at 03:56 on Sep 5, 2021

# ¿ Sep 5, 2021 03:51

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# ¿ May 11, 2024 07:26

Fluue: Jan 2, 2008

Thank you both! Good suggestion to use an internal constructor.

# ¿ Sep 5, 2021 16:51

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > Go: Google's Plan9 refugees are staging a breakout