parser (term)

A parser is a grammar-interpretation routine, that turns user input ("pick up the axe, then throw it at the dwarf") into discrete commands that the computer understands.

Competent parsers need to know that "give boy ice cream" is functionally identical to "give ice cream to boy". A good parser will recognize that "girl, give icecream to boy" and "tell the little girl to give the melting substance in the conical receptacle to the small grubby human male" both describe the same action.

However advanced the parser, it is up to the IF author to list every word that could possibly be used to refer to the various objects (here, the boy, the girl, and the ice cream) that are unique to a particular story. Having done so, the author can trust the parser to sort them out.