Module datafusion_expr::function

Function module contains typing and signature for built-in and user defined functions.

Functions

• return_type
  Returns the datatype of the scalar function
• signature
  the signatures supported by the function fun.

Type Definitions

• AccumulatorFunctionImplementation
  Factory that returns an accumulator for the given aggregate, given its return datatype.
• ReturnTypeFunction
  Factory that returns the functions’s return type given the input argument types
• ScalarFunctionImplementation
  Scalar function
• StateTypeFunction
  Factory that returns the types used by an aggregator to serialize its state, given its return datatype.