re = /(?<=[=,])\s*[A-Za-z2]+(?=\()(?![^']*'!)/
str = '=VLOOKUP($A9,\'Summary\'!$A$10:$C$30,3,FALSE)
=IFERROR((C10/B10),"N/A")
=sum(\'New Chart =Data(Date)\'!L70)
=IFERROR((C10/B10),Len(E30))'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html