Trait Function 

pub trait Function:
    Display
    + Sync
    + Send {
    // Required methods
    fn name(&self) -> &str;
    fn return_type(&self, input_types: &[DataType]) -> Result<DataType>;
    fn signature(&self) -> &Signature;
    fn invoke_with_args(
        &self,
        args: ScalarFunctionArgs,
    ) -> Result<ColumnarValue>;

    // Provided method
    fn aliases(&self) -> &[String] { ... }
}

Scalar function trait, modified from databend to adapt datafusion TODO(dennis): optimize function by it’s features such as monotonicity etc.

Required Methods

fn name(&self) -> &str

Returns the name of the function, should be unique.

fn return_type(&self, input_types: &[DataType]) -> Result<DataType>

The returned data type of function execution.

fn signature(&self) -> &Signature

The signature of function.

fn invoke_with_args(&self, args: ScalarFunctionArgs) -> Result<ColumnarValue>

Provided Methods

fn aliases(&self) -> &[String]

Implementors

impl Function for DateAddFunction

impl Function for DateFormatFunction

impl Function for DateSubFunction

impl Function for IfFunction

impl Function for IsNullFunction

impl Function for GeohashFunction

impl Function for GeohashNeighboursFunction

impl Function for H3CellBase

impl Function for H3CellCenterChild

impl Function for H3CellCenterLatLng

impl Function for H3CellContains

impl Function for H3CellDistanceEuclideanDegree

impl Function for H3CellDistanceSphereKm

impl Function for H3CellIsPentagon

impl Function for H3CellParent

impl Function for H3CellResolution

impl Function for H3CellToChildPos

impl Function for H3CellToChildren

impl Function for H3CellToChildrenSize

impl Function for H3CellToString

impl Function for H3ChildPosToCell

impl Function for H3GridDisk

impl Function for H3GridDiskDistances

impl Function for H3GridDistance

impl Function for H3GridPathCells

impl Function for H3LatLngToCell

impl Function for H3LatLngToCellString

impl Function for H3StringToCell

impl Function for STArea

impl Function for STDistance

impl Function for STDistanceSphere

impl Function for S2CellLevel

impl Function for S2CellParent

impl Function for S2CellToToken

impl Function for S2LatLngToCell

impl Function for LatLngToPointWkt

impl Function for HllCalcFunction

impl Function for Ipv4ToCidr

impl Function for Ipv6ToCidr

impl Function for Ipv4NumToString

impl Function for Ipv4StringToNum

impl Function for Ipv6NumToString

impl Function for Ipv6StringToNum

impl Function for Ipv4InRange

impl Function for Ipv6InRange

impl Function for JsonGetBool

impl Function for JsonGetFloat

impl Function for JsonGetInt

impl Function for JsonGetObject

impl Function for JsonGetString

impl Function for JsonIsArray

impl Function for JsonIsBool

impl Function for JsonIsFloat

impl Function for JsonIsInt

impl Function for JsonIsNull

impl Function for JsonIsObject

impl Function for JsonIsString

impl Function for JsonPathExistsFunction

impl Function for JsonPathMatchFunction

impl Function for JsonToStringFunction

impl Function for ParseJsonFunction

impl Function for MatchesFunction

impl Function for MatchesTermFunction

impl Function for ClampFunction

impl Function for ClampMaxFunction

impl Function for ClampMinFunction

impl Function for ModuloFunction

impl Function for RateFunction

impl Function for RangeFunction

impl Function for DecodePrimaryKeyFunction

impl Function for RegexpExtractFunction

impl Function for ToUnixtimeFunction

impl Function for UddSketchCalcFunction

impl Function for ParseVectorFunction

impl Function for VectorToStringFunction

impl Function for CosDistanceFunction

impl Function for DotProductFunction

impl Function for L2SqDistanceFunction

impl Function for ElemAvgFunction

impl Function for ElemProductFunction

impl Function for ElemSumFunction

impl Function for ScalarAddFunction

impl Function for ScalarMulFunction

impl Function for VectorAddFunction

impl Function for VectorDimFunction

impl Function for VectorDivFunction

impl Function for VectorKthElemFunction

impl Function for VectorMulFunction

impl Function for VectorNormFunction

impl Function for VectorSubFunction

impl Function for VectorSubvectorFunction

impl Function for BuildFunction

impl Function for ConnectionIdFunction

impl Function for DatabaseFunction

impl Function for PgBackendPidFunction

impl Function for ReadPreferenceFunction

impl Function for ColDescriptionFunction

impl Function for CurrentDatabaseFunction

impl Function for CurrentSchemaFunction

impl Function for CurrentSchemasFunction

impl Function for ObjDescriptionFunction

impl Function for PgMyTempSchemaFunction

PostgreSQL pg_my_temp_schema - returns 0 (no temp schema) for compatibility

impl Function for SessionUserFunction

impl Function for ShobjDescriptionFunction

impl Function for TimezoneFunction

impl Function for VersionFunction

impl<T: StFunction + Display + Send + Sync> Function for T