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block(1)

conditional_statements(1)

statement_block(1)

task_definition(1)

transaction_block(1)

acmsxp_information(1)

statement(1)  —  Commands

Digital

NAME

Statement − describes work in a task definition, provides flow control between statements, and groups statements in blocks

SYNOPSIS

 [<label-name>:] { <statement> ; [ ... ] } [ ... ]
 

PARAMETERS

 

       •label-name
 
An internal unqualified identifier terminated with a colon (:) character. The label is associated with a statement within a task definition, for use in flow control operations. The scope of the label depends on whether it is defined on a statement, at the beginning of a statement block or transaction block, or within an exception handler.

       •statement
 
A statement or list of statements valid for the context in which they appear. Each statement is terminated by a semicolon (;) character. The following are the STDL statements.
 
 assignment
 AUDIT
 CALL PRESENTATION
 CALL PROCEDURE
 CALL TASK
 CANCEL TASK SUBMIT
 CONTROL FIELD
 DEQUEUE
 ENQUEUE RECORD
 EXIT BLOCK
 EXIT TASK
 GET MESSAGE
 GO TO
 IF THEN ELSE
 RAISE EXCEPTION
 READ QUEUE
 RERAISE EXCEPTION
 RESTART TRANSACTION
 SELECT FIRST TRUE OF
 STATEMENT BLOCK
 SUBMIT TASK
 TRANSACTION BLOCK
 WHILE DO
 
The statements together constitute a statement list.

DESCRIPTION

 
The rules for using statements depend on whether the task definition in which they appear is noncomposable or composable and whether they appear within a transaction block in a noncomposable task.
 
Some statements access transactional resources and therefore must be used only within a transaction. In a noncomposable task, these statements must appear within a transaction block. In a composable task, a transaction block is illegal and these statements execute within the transaction of the caller. For a description of statement usage in a task, see the task_definition man page. The stdl_syntax man page describes the elements of statements. 
 
Normal execution for a statement list is to execute all the statements sequentially and complete with default flow control.
 
Deviation from the normal execution flow occurs when a statement completes with one of the following:

oExplicit EXIT BLOCK or EXIT TASK flow control. The statement list completes with the same explicit flow control with which the statement completed. 

oExplicit GO TO flow control if the target of the GO TO statement is in the statement list and the normal execution flow resumes with the target statement. If normal execution flow does not resume with the target statement, the statement list completes with explicit flow control. 

An exception raised by the statement. The statement list completes with the exception raised by the statement. 
 

RELATED INFORMATION

Syntax: block(1), conditional_statements(1), statement_block(1), task_definition(1), transaction_block(1)

acmsxp_information(1)

Typewritten Software • bear@typewritten.org • Edmonds, WA 98026