If you come around something like

{}

you might think it is an empty block, but it isn't.

Try the following: 

perl -e '{};{}' # works
perl -e '{1}{}' # works
perl -e '{}{1}' # works
perl -e '{}{}'  # doesn't work

[download]

Why? Because {} can be meant as an empty block or as an hashref, and to perl, those are two hashrefs.

perl apparently "uses fuzzy logic to guess whether you meant a {} to be a block or a hash-ref. It assigns points based on the surrounding code and the stuff inside the {} and then picks based on the resulting score" (this information courtesy of samtregar).

To see what happens for yourself, try this

perl -MO=Terse -e '{};{}'

This {} thing is actually a bug in perl. After all, you give it well written code and it complains about a syntax error.

In reply to Is { } an empty block or a bug in perl? by cog

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