5-Aug-1998
                                                                
This directory contains the procedure idlv4_to_v5.pro for converting an IDL
V4.0 (or earlier) procedure file to use the IDL V5.0 convention of square 
brackets for array subscripts, and the procedure idl5to4.pro to convert V5
procedures to run under V4.0.

IDLV4_TO_V5 has the following restrictions:

(1) Only runs under IDL V5.0 and later (since it calls ROUTINE_INFO())
(2) May possibly get confused by parentheses within strings.
(3) May get confused by IDL statements that extend over multiple lines
    idlv4_to_v5 will supply a warning when it becomes confused by
    unmatched parenthesis.
(4) Do not include this procedure 'idlv4_to_v5' in the directory that 
    you are trying to convert (since it will compile the procedure 
    while executing it, and do a retall.)
(5) Conversions cannot be performed unless specified procedure(s) 
    already compile properly
(6) Will not work on IDL main programs
(7) May get confused by gaps between array name and parenthesis

IDLV4_TO_V5 requires the following supporting procedures:

ISFUNCTION() - Determine whether the IDL program(s) in a file are procedures
		or functions.
FDECOMP - Decompose a file (from IDL Astro Library)
REMOVE - Remove specified elements from specified vectors (from IDL Astro Lib)
GETTOK() - Retrieve first part of a string up to a character token (from IAL)
MATCH - Find matching elements in two arrays (from IAL)


**************************************************************

Also available is the procedure idl5to4.pro to remove all square subscripts
in a V5.0 procedure, so that it can run under V4.0.    This procedure was
written by William Thompson at Goddard Space Flight Center.     This procedure
runs under V4.0, and does not have many of the other restrictions of
IDLV5_TO_V4.    IDL5TO4.PRO requires the following supporting procedures:  

BREAK_FILE, CONCAT_DIR, DATA_CHK, DATATYPE, FILE_EXIST, FIND_ALL_DIR,
FIND_FILE, FIND_FILES OS_FAMILY(), TAG_EXIST

***Note that several of these supporting procedures (e.g. FILE_EXIST, FIND_FILE)
do not exist in the IDL Astronomy Library and must be copied from either this
directory or from the Solar Library at
(http://sohowww.nascom.nasa.gov/solarsoft/gen/idl/).***


June 2001:    Include FIND_ALL_DIR procedure

August 1998:  Replace idlv5_to_v4 with idl5to4, which is a much less restrictive
              conversion procedure written by William Thompson.

September 1997: Updated idlv4_to_v5 to recognize that variable names can 
                include numerals.     Use V5.0 versions of FDECOMP, REMOVE, 
		and GETTOK

October 1997:   Never put square brackets after an intrinsic IDL function name,
                even if it is also a variable name.

February 1997:  Added idlv5_to_v4