pTAL Conversion Guide

Arrays

pTAL Conversion Guide—527302-002

9-2

Constant Lists in Array Declarations

pTAL introduces two requirements for array declarations, as follows:

•

If an array declaration includes an initialization string, the number of bits in the

array and in the initialization string must be equal.

•

If the alignment of the elements of the initialization string under SHARED2 rules

and SHARED8 rules is different, you must specify a FIELDALIGN clause in the

initialization string.

pTAL rules for initializing arrays are more restrictive than TAL rules. In pTAL, the

number of bits in a constant list you assign to an array must be the same as the

number of bits in the array. Read-only arrays, however, do not have a declared length

and, therefore, have slightly different rules.

Topics:

•

Read-Only Arrays on page 9-2

•

Nonstring Arrays on page 9-3

Read-Only Arrays

TAL

You can assign any constant string to any read-only array.

pTAL

•

The number of bits in the initialization string must equal the number of bits in the

read-only array.

•

If the read-only-array declaration does not specify array bounds, the number of bits

in the initialization string must be an integral multiple of the number of bits in the

array’s base type.

Example 9-2. Constant Lists in Read-Only Array Declarations

(pTAL) (page1of2)

Invalid:

string u[0:3] = 'P' := [1,2,3]; ! ERROR: Initialization size

! (24 bits) must equal

! array size (32 bits)

int x = 'P' := "abc"; ! ERROR: Initialization size

! must be integral multiple

! of array’s base type size