RegexLocate and RegexLocateUp (Stringlist functions)

and RegexLocateUp: Find item in Stringlist

RegexLocate and RegexLocateUp are a members of the Stringlist class.

These methods use a regular expression (regex) to locate an item in the method Stringlist. They return the item number of the first item that the regex matches. Information about the regular expression matching rules observed is provided in Regex processing. The methods are available as of Version 6.9 of the Sirius Mods. Both functions proceed item-by-item through the Stringlist. RegexLocate starts by default from item 1, the first item in the Stringlist, or it starts from the item you specify. RegexLocateUp starts from the item .n you specify and proceeds "upward" to item n-1, then n-2, and so on. RegexLocate and RegexLocateUp accept one required and five optional arguments, and they return a number. They are also callable methods. Specifying an invalid argument results in request cancellation.

RegexLocate and RogexLocateUp Syntax

[%itemnum =] %sl:RegexLocate[Up] (regex, [startitem] -
                        [, StartCol=num1] -
                        [, EndCol=num2] -
                        [, Options=string] -
                        [, Status=num])

Syntax Terms

%itemnum

If specified, a numeric variable that is set to the number of the %sl item matched by regex, or it is 0 if no items are matched.

%sl

A Stringlist object.

regex

A string that is interpreted as a regular expression and is applied to the %sl method Stringlist items to determine whether the regex finds a match.

startitem

The item number from which the regex matching is to begin. If this item is not matched, the method attempts to match the item with the next higher (if RegexLocate) or lower (if RegexLocateUp) item number, and so on. This numeric value is an optional argument that defaults to 1 (if RegexLocate) or to the number of items in %sl (if RegexLocateUp). This value must not be negative and must not be greater than the number of sl items. Setting this argument to 0 is the same as setting it to 1.

StartCol= num1

The StartCol argument (name required) is an optional number that specifies the starting column of the range of columns in which the matched string must be located. If the argument is specified, its value must be greater than or equal to 1 and less than or equal to the EndCol argument value. If the argument is omitted, its default value is 1. If you specify a value that is greater than the length of a particular %sl item, regex is matched against the empty string for that item.

EndCol= num2

The EndCol argument (name required) is an optional number that specifies the ending column of the range of columns in which the matched string must be located. If the argument is specified, its value must be greater than or equal to 1, greater than or equal to the StartCol argument value, and less than or equal to 6124. If the EndCol argument is omitted, its default value is 6124.

If the EndCol argument is omitted and a %sl item exceeds 6124 bytes, the run is cancelled.

Options= string

The Options argument (name required) is an optional string of options. The options are single letters, which may be specified in uppercase or lowercase, in any combination, and separated by blanks or not separated. For more information about these options, see Regex processing.

I

Do case-insensitive matching between string and regex.

S

Dot-All mode: a dot (..) can match any character, including carriage return and linefeed.

M

Multi-line mode: let anchor characters match end-of-line indicators wherever the indicator appears in the input string. M mode is ignored if C (XML Schema) mode is specified.

C

Do the match according to XML Schema regex rules. Each regex is implicitly anchored at the beginning and end, and no characters serve as anchors. For more information, see :hdref refid=regxml..

Status= num

The Status argument (name required) is optional; if specified, it is set to an integer code. These values are possible:

n

The number of the %sl item that is first matched.

0

No match: no items in :hp1.%sl:ehp1. were matched by :hp1.regex:ehp1..

-2

The %startitem value is invalid (either a negative value or a value greater than the number of list items), or the method Stringlist is empty.

-1nnn

The pattern in regex is invalid.nnn, the absolute value of the return minus 1000, gives the 1-based position of the character being scanned when the error was discovered. The value for an error occurring at end-of-string is the length of the string + 1. Prior to Version 7.0 of the Sirius Mods, an invalid regex results in a Status value of .-1.

If you omit this argument and a negative Status value is to be returned, the run is cancelled.

Usage Notes

• It is strongly recommended that you protect your environment from regex processing demands on PDL and STBL space by setting, say, .UTABLE LPDLST 3000 and .UTABLE LSTBL 9000. For further discussion of this, see :hdref refid=ulcons..
• The regex matching is limited to the first 6124 bytes of each item.
• The request is cancelled in any of these cases:
  • You specify an invalid argument option.
  • You omit the Status argument and a situation occurs that would cause a negative Status value.
  • You omit the EndCol argument and the length of an %sl item exceeds 6124 bytes.
• For information about additional methods and $functions that support regular expressions, see :hdref refid=regexp..

Examples

In the following code fragment, RegexLocate is applied to the method Stringlist .%sl to find the first occurrence of the string .'CUST'. If this is successful, the containing item is copied to a new Stringlist. The matching is done case-insensitively, and the starting item is the beginning of the list, by default. Substituting RegexLocateUp for RegexLocate in the example would find the last occurrence of .'CUST'.

...
%sl = new
text to %sl
%n = %list:findImageItem(%cust:ssn)
if %n then
%list:replaceImage(%n, 'CUST')
else
%list:addimage('CUST')
end if
end text

%opt='i'
%regex = '''cust'''
%itemnum = %sl:RegexLocate(%regex, Options=%opt, Status=%st)
If (%itemnum EQ 0) then
Print 'Status from RegexLocate[Up] is ' %st
Else
Print %regex ' matches item ' %itemnum
Print 'Now for %sl2 . . . '
%sl2 = new
%i = %sl2:CopyItems(%sl, %itemnum, '1')
%i = %sl2:Print
End If
...