Understanding whitespace

[Collin Peters]

I have a piece of text that I am parsing that looks like this:
c: winsize0 is {"1919","1925","1936"}
The above rule matches fine with the rule IFSTATEMENT:
VARIABLE        : /\w[a-z0-9-\/]*/i     
DOMAIN_COMP     : /is\s+[not]*/ix
DOMAIN          : VALUES(s)  # {"vsk", "vr", ...}
IFSTATEMENT     : VARIABLE DOMAIN_COMP '{' DOMAIN '}'
My question is how to continue to get a match with:
c: winsize0 is{"1919","1925","1936"}
Notice the missing space between the is and the '{'

Collin