Elm in Action

C.3. When memory locations stay the same

Custom type variants that don’t hold data—for example, the values True, False, and Nothing—always have the same memory location. They work the same way with lazy as strings and numbers do. (In contrast, values created with Just might not have the same memory locations, because Just holds data.)

Other values keep the same memory location when they are passed around. Table C.2 shows some ways to get a value with the same memory location as another value.

Table C.2. Ways to get a value with the same memory location as another value

Operation yielding same memory location	Examples
Assigning it to another constant	sameMemory = oldValue
Reading it from a record field	sameMemory = record.oldValue ...