regex - Regular expression - match all words but match unique words only once

Question

Is it possible to use a regular expression to match all words but match unique words only once? I am aware there are other ways of doing this however I'm interested in knowing if this is possible with the use of a regular expression.

For example I currently have the following expression:

(w+)(?!.*1)

and the following string:

glass shoes door window door glasses. window glasses

For the most part the expression works and matches the following words:

shoes
door 
window
glasses

There are two issues with this:

1. A match for a substring is being made on "glasses" with "glass", this is incorrect.

2. "glasses" and "glasses." should match but currently do not.

The final match should be:

shoes 
door 
window 
glasses 
glass 

Answer 1

Pretty close, just readd the in the negative lookahead

/(w+)(?!.*1)/

See it on Rubular