Card Effect Compilation

Card Effect Compilation

How to turn a played card into an ordered series of executable commands. This needs to remember to respect control blocks, external modifiers, other effects that could be triggered along the way (maybe more of an execution problem than compilation), and various other issues.

"Compilation" needs to happen as cards are played (not as they are created), because effects may need to read the current board state to work properly (and then those differences can cascade down to affect other effects).

This informs data structures for card effects and the shape of effect handling code.

What does an effect look like?

Each card has an ordered list of instructions, represented in bytecode. During execution, instructions are pushed onto a stack, and taken off incrementally. When an instruction is read from the stack, some corresponding code is run. Effects are chunks of instructions, put together in a deliberate way.

Effect Types

Effect Name	Byte structure (after HEAD)
Loop	INT(num times), BYTES to compile, ENDLOOP
Forloop	INT (id), LIST, BYTES (chunks + placeholders), ENDLOOP
Add to Hand
Set Points	PLAYER, INT
Set Max Hand Size	PLAYER, INT
Set Draw Size	PLAYER, INT
Set Win Condition	Set a player's win condition
Send To Hand	Put a card in a player's hand
Discard	Put card in discard
Destroy	Destroy a card
Change Owner	Give a played card to a player
Duplicate	Duplicate a card
Deck	Put a card in deck
Add Tag	Add tag to a card
Set Flag	Set global flag
Set Counter	Set global counter
Set Var	Set global variable
Toggle Turn Order	Reverse turn order
Set Player Turn	Make it a player's turn
Add Listener	Add a global listener
Roll Dice	Roll a 1DX and return result
Shuffle Deck	Shuffle deck
OOE	Out of engine