# Functions
Deref returns the target type that t refers to and the AST it belongs to.
IDLPrefix returns the file name without extension.
NewChecker creates a checker.
ResolveSymbols checks the existence of each symbol in the current AST and build a name-to-category mapping for all locally-defined symbols.
SplitType tries to split the given ID into two part: the name of an included IDL without file extension and the type name in that IDL.
SplitValue tries to find any possible resolution of the given ID assuming it is a name of a constant value or an enum value.
# Interfaces
Checker reports whether there are semantic errors in the AST and produces warning messages for non-fatal errors.