## Word renaming

Monday, April 14, 2008

Several words have been renamed and moved around to make Factor more consistent:

- new -> new-sequence
- construct-empty -> new
- construct-boa -> boa
- diff -> assoc-diff
- union -> assoc-union
- intersect -> assoc-intersect
- seq-diff -> diff
- seq-intersect -> intersect

To make things symmetrical, a new word `union`

operates on sequences.

Somehow, `seq-diff`

and `seq-intersect`

were implemented as O(n^2)
algorithms. Now, they use hashtables and are O(n).

Lastly, a new vocabulary named ``sets’’ contains the set theoretic
words, along with a new word `unique`

that converts a sequence to a hash
table whose keys and values are the same. An efficient union and
intersect are implemented in terms of this word.