Scripting Guide - SAS

580 JSL Syntax Reference Appendix A
Character Pattern Functions
Returns
A pattern.
Argument
string a string.
Pat Succeed()
Description
Constructs a pattern that always succeeds, even when the matcher backs into it. It matches the null
string.
Returns
1 when the match succeeds.
Argument
none
Pat Tab(int)
Description
Constructs a pattern that matches forward to position int in the source string. It can match 0 or more
characters. It fails if it would have to move backwards or beyond the end of the string.
Returns
A pattern.
Argument
int an integer that specifies a position in a string.
Pat Test(expr)
Description
Constructs a pattern that succeeds and matches the null string if expr is not zero and fails otherwise.
Returns
A pattern.
Argument
expr An expression.
Note
Usually the argument is wrapped with expr() because the test needs to be made on the current value of
variables set by Pat Immediate, Pat Conditional, and Pat At. Without expr, the test is based on
values that were known when the pattern was constructed, which means the test always succeeds or
always fails at pattern execution time, which is probably not what you want.
Example
nCats = 0;
whichCat = 3;
string = "catch a catnapping cat in a catsup factory";
rc = Pat Match(string, "cat" + Pat Test(expr(nCats=nCats+1; nCats ==
whichCat)), "dog");
show(rc, string, nCats);