Storage.md

Storage

Dynamic memory allocation module. Provides the low-level allocation and deallocation procedures used internally by NEW and DISPOSE.

Exported Procedures

PROCEDURE ALLOCATE(VAR p: ADDRESS; size: CARDINAL);
PROCEDURE DEALLOCATE(VAR p: ADDRESS; size: CARDINAL);

Notes

• ALLOCATE allocates size bytes and stores the pointer in p.
• DEALLOCATE frees the memory at p and sets p to NIL.
• The built-in NEW(p) expands to ALLOCATE(p, TSIZE(T)) where T is the base type of the pointer p.
• The built-in DISPOSE(p) expands to DEALLOCATE(p, TSIZE(T)).
• Import Storage (or at least ALLOCATE) to use NEW/DISPOSE.

Example

MODULE StorageDemo;
FROM Storage IMPORT ALLOCATE, DEALLOCATE;
TYPE
  NodePtr = POINTER TO Node;
  Node = RECORD
    value: INTEGER;
    next: NodePtr;
  END;
VAR p: NodePtr;
BEGIN
  NEW(p);
  p^.value := 42;
  p^.next := NIL;
  DISPOSE(p);
END StorageDemo.