Perl hash substitution with special characters in keys

Question

My current script will take an expression, ex:

my $expression = \'( a || b || c )\';

and go through each boolean combination of inputs using su

Answer 1

Problem 1

You use the pattern a* thinking it will match only a*, but a* means "0 or more a". You can use quotemeta to convert text into a regex pattern that matches that text.

Replace

my $keys = join '|', keys %stimhash;

with

my $keys = join '|', map quotemeta, keys %stimhash;

Problem 2

\b

is basically

(?<!\w)(?=\w)|(?<=\w)(?!\w)

But * (like the space) isn't a word character. The solution might be to replace

s/($keys)\b/$stimhash{$1}/g

with

s/($keys)(?![\w*])/$stimhash{$1}/g

though the following make more sense to me

s/(?<![\w*])($keys)(?![\w*])/$stimhash{$1}/g

Personally, I'd use

s{([\w*]+)}{ $stimhash{$1} // $1 }eg