Module datafusion_expr_common::signature

Signature module contains foundational types that are used to represent signatures, types, and return types of functions in DataFusion.

Structs

• Signature
  Defines the supported argument types (TypeSignature) and Volatility for a function.

Enums

• ArrayFunctionSignature
• TypeSignature
  A function’s type signature defines the types of arguments the function supports.
• Volatility
  A function’s volatility, which defines the functions eligibility for certain optimizations

Constants

• FIXED_SIZE_LIST_WILDCARD
  Constant that is used as a placeholder for any valid fixed size list. This is used where a function can accept a fixed size list type with any valid length. It exists to avoid the need to enumerate all possible fixed size list lengths.
• TIMEZONE_WILDCARD
  Constant that is used as a placeholder for any valid timezone. This is used where a function can accept a timestamp type with any valid timezone, it exists to avoid the need to enumerate all possible timezones. See TypeSignature for more details.