# Functions
GetEvaluator returns evaluator.
RegisterFunction registers function in metadata and fills out all Description structs.
RegisterFunctionWithFilename registers function in metadata and fills out all Description structs.
RegisterRewriteFunction registers function for a rewrite phase in metadata and fills out all Description structs.
RegisterRewriteFunctionWithFilename registers function for a rewrite phase in metadata and fills out all Description structs.
SetEvaluator sets new evaluator function to be default for everything that needs it.
# Variables
FunctionMD is actual global variable that stores metadata.