TAL Reference Manual

Procedures

TAL Reference Manual—526371-001

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Usage Considerations

Labels are the only declarable objects that you need not declare before using them.

For best program management, however, declare all labels. For example, declaring a

label helps ensure that you access the label, not a variable that has the same identifier.

Local Labels

You can use a local label as follows:

1. Declare the label inside a procedure at the local level.

2. Place the label identifier and a colon (:) preceding a local statement in the same

procedure.

3. Branch to the label by using local or sublocal GOTO statements in the same

procedure.

Future software platforms require that you declare local labels that are referenced by

sublocal GOTO statements.

Sublocal Labels

You can use a sublocal label as follows:

1. Declare the label inside a subprocedure.

2. Place the label identifier and a colon (:) preceding a sublocal statement in the

same subprocedure.

3. Branch to the label by using sublocal GOTO statements in the same subprocedure.

Examples of Label Declarations

1. In this example, a local GOTO statement branches to a local label named ADDR:

PROC p;

BEGIN

LABEL addr; !Declare label

INT result;

INT op1 := 5;

INT op2 := 28;

addr:

result := op1 + op2; !Labeled statement

op1 := op2 * 299;

IF result < 100 THEN

GOTO addr; !Branch to label

!Some code

END;