TAL Reference Manual

Structures

TAL Reference Manual—526371-001

8-10

Definition Substructure Declaration

A definition substructure describes a layout and allocates storage for it.

identifier

is the identifier of the definition substructure.

lower-bound

is an INT constant expression (in the range –32,768 through 32,767) that specifies

the index (relative to the zeroth substructure occurrence) of the first substructure

occurrence you want allocated. Each occurrence is one copy of the substructure.

The default value is 0.

upper-bound

is an INT constant expression (in the range –32,768 through 32,767) that specifies

the index (relative to the zeroth substructure occurrence) of the last substructure

occurrence you want allocated. The default value is 0. For a single-occurrence

substructure, omit both bounds or specify the same value for both bounds.

substructure-layout

is the same BEGIN-END construct as for structures. It can contain declarations for

simple variables, arrays, substructures, filler bits, filler bytes, redefinitions, simple

pointers, and structure pointers. The size of one substructure occurrence is the

size of the layout, either in odd or even bytes. The total layout for one occurrence

of the encompassing structure must not exceed 32,767 bytes.

VST0806.vsd

identifier

STRUCT

[ : ]

lower-

bound

upper-

bound

; ;

substructure-

layout