CardSimEngine/cardsim/player.go

package cardsim

import "math/rand"

// Player stores all gameplay state for one player at a specific point in time.
// Game-specific data is stored in Stats.
//
// Player is a generic type -- see https://go.dev/blog/intro-generics for more
// information on how these work. Think of "Player" as a "type of type" --
// when you create one, you tell it what kind of data it needs to keep for
// the simulation itself, and each Player that works with a different kind of
// data is a different kind of Player and the compiler will help you with that.
// This is the same idea as "slice of something" or "map from something to
// something" -- different kinds of Players are different from each other and
// "know" what type of data they use, so the compiler can tell you if you're
// using the wrong type.
//
// Generic types have to use a placeholder to represent the type (or types --
// consider maps, which have both keys and values) that will be more specific
// when the type is actually used. They're called "type parameters", like
// function parameters, because they're the same kind of idea. A function puts
// its parameters into variables so you can write a function that works with
// whatever data it gets; a generic type takes type parameters and represents
// them with type placeholders so you can write a *type* that works with
// whatever specific other types it gets.
//
// Just like function parameters have a type that says what kind of data the
// function works with, type parameters have a "type constraint" that says what
// kind of types the generic type works with. Go already has a familiar way
// to express the idea of "what a type has to do": `interface`. In Go, type
// constraints are just interfaces.
//
// But wait, why use generics at all? Can't we just use an interface in the
// normal way instead of doing this thing? Well, yes, we could, but then the
// compiler doesn't know that the "real types" for things matching these
// interfaces all have to actually be the same type. The compiler will stop
// you from putting an `Orange` into a `[]Apple`, but it wouldn't stop you from
// putting a `Fruit` into a `[]Fruit` because, well, of course it wouldn't,
// they're the same type.
//
// Different simulation games made with `cardsim` are different. Rules made for
// simulating the economy of a kobold colony and mine wouldn't work at all with
// data for a simulation about three flocks of otter-gryphons having a
// territory conflict over a river full of fish. By using generics, the compiler
// can recognize functions and data and types intended for different simulation
// games and prevent you from using the wrong one, when it wouldn't be able to
// if all this stuff was written for "some simulation game, don't care what".
//
// Generic interfaces (like `Card[C]`, `Rule[C]`, `InfoPanel[C]`, and more)
// don't mean you have to write generics of your own. It's exactly the opposite!
// Because the interface has this extra type in it, you only need to implement
// the specific kind of interface that works with your game. There's more detail
// on this in the comment on `Rule[C]`.
type Player[C StatsCollection] struct {
	Stats             C
	Name              string
	Deck              *Deck[C]
	Hand              []Card[C]
	HandLimit         int
	ActionsPerTurn    int
	ActionsRemaining  int
	PermanentActions  []Card[C]
	InfoPanels        []InfoPanel[C]
	Prompt            InfoPanel[C]
	Rules             *RuleCollection[C]
	Rand              rand.Rand
	Turn              int
	TemporaryMessages []Message
	TemporaryPanels   []InfoPanel[C]

	DebugLevel int
}