Advanced Programming Guide

A.2 Internal Representations of Data Types • 345it, and relying on it not to change. The normal procedure to modify astructure is to copy it, and then to modify the copy. Structures that areno longer used are eventually reclaimed by the garbage collector.The following figures describe each of the 60 structures currently implementedin Maple, along with the constraints on their length and contents.The 6-bit numeric value identifying the type of structure is of littleinterest, so symbolic names will be used.Logical ANDMaple syntax: expr and exprLength: 3Assignment StatementMaple syntax: name := exprLength: 3AND ∧ expr ∧ exprASSIGN ∧ name ∧ exprThe name entry should evaluate to an assignable object: a NAME,FUNCTION, or TABLEREF structure.Binary ObjectMaple syntax: noneLength: arbitraryBINARY data . . .The BINARY structure can hold any arbitrary data. It is not useddirectly as a Maple object, but is used as storage for large blocks of datainside other Maple objects (currently only RTABLEs). It is also sometimesused as temporary storage space during various kernel operations.Break StatementMaple syntax: breakLength: 1BREAK