Memory and locals

Memory

memory hasPower: bool = startsPowered "Power"
memory rang: int = 0 "Rings today"

• memory is the instance's lasting state: it changes in transactions, it is saved, and a world opened again goes on from it.
• Its label names it in the editor and in Play's Objects panel.
• The initial value is computed once, when the instance is first set up; it must be a pure expression of literals and properties.
• was "oldName" carries the old name's value over in a migration (Saving and migration).

Memory belongs to its script; other scripts cannot see it. A value others need goes into a contract field.

Local variables

let total = business.visitors + 1      // immutable, type inferred
var count = 0                          // mutable
var left: int = rings                  // type written

• let is immutable, var mutable; without a type, the type comes from the value.
• Both are local to their block and to each turn of a loop.
• A local cannot have the name of anything at the script's level or in the standard library (Names).