The Typer Definition
This tutorial describes the possibilities of defining a type provider (or typer, for short). In the typer definition you provide the information necessary to do type checking.
Three-level definition
As explained in Three Levels of Customization the generated typer can be defined in three levels. For each concept in the AST the typer will
- use the hand-made typing rule(s), when present. Otherwise, the typer will
- use to the typing rule(s) generated from the typer definition, when this definition is present.
There are no default typing rules, so the typer does not have a fallback to a third level, that is, when ask for the type of an AST node the typer will simply return a null value.
Content
In Typer Files you can find an explanation of the parts of a typer definition. In Typer Example you can find an example of commonly used types and how to define them.