It's not a false economy if, for legibility reasons: 

m/a[ ]b/      # You wish to make it obvious that a space is needed.

m/a[ ]{2,5}b/ # You wish to define a quantifier on a whitespace
m/a[ ]+b/     # character that would otherwise be difficult to read.

m/a[ ]b/x     # You're using the /x modifier where whitespace
              # is ignored by default.

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Dave

In reply to Re^2: Why would one want in a regex a class with only a single entry? by davido
in thread Why would one want in a regex a class with only a single entry? by ack

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