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 %TITLE 'CHMPAREN - handle parentheses'
MODULE CHMPAREN (				! Handle parentheses
		IDENT = '3-003'			! File: CHMPAREN.BLI Edit: GB3003
		) =
BEGIN
!
!			  COPYRIGHT (c) 1981, 1985 BY
!	      DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASS.
!		ALL RIGHTS RESERVED.
!
! THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY BE USED AND  COPIED
! ONLY  IN  ACCORDANCE  WITH  THE  TERMS  OF  SUCH  LICENSE AND WITH THE
! INCLUSION OF THE ABOVE COPYRIGHT NOTICE.  THIS SOFTWARE OR  ANY  OTHER
! COPIES  THEREOF MAY NOT BE PROVIDED OR OTHERWISE MADE AVAILABLE TO ANY
! OTHER PERSON.  NO TITLE TO AND OWNERSHIP OF  THE  SOFTWARE  IS  HEREBY
! TRANSFERRED.
!
! THE INFORMATION IN THIS SOFTWARE IS SUBJECT TO CHANGE  WITHOUT  NOTICE
! AND  SHOULD  NOT  BE  CONSTRUED  AS  A COMMITMENT BY DIGITAL EQUIPMENT
! CORPORATION.
!
! DIGITAL ASSUMES NO RESPONSIBILITY FOR THE USE OR  RELIABILITY  OF  ITS
! SOFTWARE ON EQUIPMENT WHICH IS NOT SUPPLIED BY DIGITAL.
!

!++
! FACILITY:	EDT -- The DEC Standard Editor
!
! ABSTRACT:
!
!	This module implements a parenthesized string of commands.
!
! ENVIRONMENT:	Runs at any access mode - AST reentrant
!
! AUTHOR: Bob Kushlis, CREATION DATE: Unknown
!
! MODIFIED BY:
!
! 1-001	- Original.  DJS 04-Feb-1981.  This module was created by
!	extracting the routine EDT$$PARENT  from module CHANGE.BLI.
! 1-002	- Regularize headers.  JBS 03-Mar-1981
! 1-003	- Use new message codes.  JBS 04-Aug-1981
! 1-004	- Add return values.  JBS 02-Oct-1981
! 1-005	- Add an entry point so that this module can be loaded back into
!	   memory after calling the change mode parser.  Also, use a different
!	   symbol for the name of the change mode parser so the call can be
!	   ignored by the overlay analyzer (and so that the call can be
!	   intercepted by a routine which will load us back into memory).
!	   JBS 02-Apr-1982
! 1-006	- Set a flag if control C actually aborts something.  JBS 24-May-1982
! 1-007	- If an error occurs in processing the commands inside parens, such
!	   as string not found, continue after the right paren.  JBS 23-Feb-1983
! 3-001 - Change all occurrences of CMD_BUF to CMD_PTR.  GB 07-Apr-1983
! 3-002 - Don't need overlay code. CJG 17-Apr-1983
! 3-003 - Add updates from V3 source kit.  GB 27-Apr-1983
!--

%SBTTL 'Declarations'
!
! TABLE OF CONTENTS:
!

REQUIRE 'EDTSRC:TRAROUNAM';

FORWARD ROUTINE
    EDT$$PARENT;				! Collect and execute a parenthesized string of commands

!
! INCLUDE FILES:
!

REQUIRE 'EDTSRC:EDTREQ';

!
! MACROS:
!
!	NONE
!
! EQUATED SYMBOLS:
!
!	NONE
!
! OWN STORAGE:
!
!	NONE
!
! EXTERNAL REFERENCES:
!
!	In the routine

%SBTTL 'EDT$$PARENT  - handle parentheses'

GLOBAL ROUTINE EDT$$PARENT (			! Handle parentheses
    COUNT, 					! Number of times to execute
    EXECUTE					! 1 = execute the commands
    ) =

!++
! FUNCTIONAL DESCRIPTION:
!
!	This routine implements a parenthesized string of commands.  The
!	string is analyzed without execution in order to verify it syntactically,
!	and find the end of the string.  It is then executed COUNT times, or until
!	a command in the string fails.  In either case, CMD_PTR is left pointing
!	at the first character after the parenthesized command list.
!
! FORMAL PARAMETERS:
!
!  COUNT		Number of times to execute
!
!  EXECUTE		1 = execute the commands
!
! IMPLICIT INPUTS:
!
!	CMD_PTR
!
! IMPLICIT OUTPUTS:
!
!	CC_DONE
!
! ROUTINE VALUE:
!
!	1 = ok, 0 = control C , 2 = end of journal file
!
! SIDE EFFECTS:
!
!	NONE
!
!--

    BEGIN

    EXTERNAL ROUTINE
	EDT$$MSG_BELL : NOVALUE,		! Output a message to the terminal with a warning bell
	EDT$$CHK_CC,				! Check to see if a CTRL/C has been typed
	EDT$$CHM_PAREXE;		! Parse and execute a change mode command string

    EXTERNAL
	CMD_PTR,				! Command string pointer
	CC_DONE;				! Set to 1 if control C actually aborts something

    MESSAGES ((PARENMIS));

    LOCAL
	SUCCEED,
	COM_END,
	COM_START;

    CMD_PTR = COM_START = CH$PLUS (.CMD_PTR, 1);
!+
! Check syntax and find the end of the command.
!-
    SUCCEED = EDT$$CHM_PAREXE (0);

    IF (.SUCCEED NEQ 1) THEN RETURN (.SUCCEED);

    COM_END = .CMD_PTR;

!+
! If we are not positioned on the right paren we have a syntax error.
!-
    IF (CH$RCHAR (.COM_END) NEQ %C')')
    THEN
	BEGIN
	EDT$$MSG_BELL (EDT$_PARENMIS);
	RETURN (0);
	END;

    IF .EXECUTE
    THEN

	DECR I FROM .COUNT - 1 TO 0 DO
	    BEGIN

	    IF EDT$$CHK_CC ()
	    THEN
		BEGIN
		CC_DONE = 1;
		RETURN (0);
		END;

	    CMD_PTR = .COM_START;
	    SUCCEED = EDT$$CHM_PAREXE (1);

	    IF (.SUCCEED NEQ 1) THEN EXITLOOP;

	    END;
    CMD_PTR = CH$PLUS (.COM_END, 1);

!+
! Don't indicate an error in executing the command within parens as an error
! in executing this command.  This allows multiple commands to be executed
! terminated by search failures.
!-

    IF (.SUCCEED EQL 0) THEN SUCCEED = 1;
    RETURN (.SUCCEED);
    END;					! of routine EDT$PARENT

END
ELUDOM