8.1 Built-in types

There are the following built-in types in the TIGER language:

String for feature values not listable such as the values of the features word or lemma

UserDefConstant for user-defined ('listable') feature values

Constant comprises both String and UserDefConstant

NT for feature constraints of nonterminal nodes

T for feature constraints of terminal nodes

FREC stands for all feature records (feature constraints), i.e. NT and T

Node stands for node descriptions

Graph means all graphs

Top means anything (in the world of syntax graphs)

The hierarchy of built-in types is visualized in the following figure. Defining a type hierarchy is introduced in the following subsection.

Figure: Built-in types

The built-in types Top, Node and Graph are only required on the conceptual level. In the current implementation, they cannot be referred to in the description language.