tonsky/datascript — pull request #8 by thegeez (2014-04-29 15:46:30+00:00)
Title: Keyword ident

From the README:
> Differences with Datomic:
> - Any value can be used as entity id, attribute or value. It’s better if they are immutable and fast to compare

Using a non number as an entity id breaks using a tempid in a transaction after that. This should fix that.