Natural for OpenVMS Version 6.3.12 for OpenVMS
 —  Statements  —

CALL LOOP

Structured Mode Syntax

CALL LOOP   operand1   [operand2] ...40
    statement ../graphics/dot3.gif
END-LOOP

Reporting Mode Syntax

CALL LOOP  operand1  [operand2] ...40
    statement ../graphics/dot3.gif
LOOP

This document covers the following topics:

For an explanation of the symbols used in the syntax diagram, see Syntax Symbols.

Related Statements: CALL | CALL FILE | CALLNAT | DEFINE SUBROUTINE | ESCAPE | FETCH | PERFORM

Belongs to Function Group: Invoking Programs and Routines


Function

The CALL LOOP statement is used to generate a processing loop that contains a call to a non-Natural program.

Unlike the CALL statement, the CALL LOOP statement results in a processing loop which is used to repeatedly call the non-Natural program. See the CALL statement for a detailed description of the CALL processing.

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Restriction

The statements AT BREAK, AT START OF DATA and AT END OF DATA must not be used within a CALL LOOP processing loop.

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Syntax Description

Operand Definition Table:

Operand Possible Structure Possible Formats Referencing Permitted Dynamic Definition
operand1 C S       A                         yes no
operand2 C S A G   A U N P I F B D T L C     yes yes

Syntax Element Description:

Syntax Element Description
operand1
Program to be Called:
The name of the non-Natural program to be called can be specified as a constant or - if different programs are to be called dependent on program logic - as an alphanumeric variable of length 1 to 8. A program name must be placed left-justified in the variable.
operand2
Parameters:
The CALL LOOP statement can have a maximum of 40 parameters. The parameter list is constructed as described for the CALL statement. Fields used in the parameter list may be initially defined in the CALL LOOP statement itself or may have been previously defined.
statement ...
Processing Loop:
The CALL LOOP statement initiates a processing loop which must be terminated with an ESCAPE statement.
END-LOOP
End of CALL LOOP Statement:

In structured mode, the Natural reserved word END-LOOP must be used to end the CALL LOOP statement.

In reporting mode, the Natural statement LOOP is used to end the CALL LOOP statement.

LOOP

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Example

DEFINE DATA LOCAL
1 PARAMETER1 (A10)
END-DEFINE
CALL LOOP 'ABC' PARAMETER1
  IF PARAMETER1 = 'END'
     ESCAPE BOTTOM
  END-IF
END-LOOP
END

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