I think once you are entering actual manufacturer part numbers you are better off deferring this to a parts database or search engine. In my uses I have been deferring this to an Octopart search. You can see this working on e.g. https://bom-builder.kitspace.org (enter something into the description field and click around on the wand icons).

We are planning to include standard part naming schemes such as Pro Electron [1] and JEDEC [2] to recognize common diodes and transistors where it makes sense. The more interesting approach to me is to actually try recognize transistor descriptions such as "npn sot23 125mW beta=200 ic>=200mA". There is some work in progress, by dvc94ch, for both approaches (if I recall correctly) on the antlr branch: https://github.com/monostable/electro-grammar/pull/4

[1]: https://en.wikipedia.org/wiki/Pro_Electron [2]: https://en.wikipedia.org/wiki/JEDEC