Enum mz_sql::func::PolymorphicCompatClass

enum PolymorphicCompatClass {
    Any,
    BestCommonAny,
    BestCommonList,
    BestCommonMap,
    StructuralEq,
}

Variants

Any

Represents the older “Any”-style matching of PG polymorphic types, which constrains all types to be of the same type, i.e. does not attempt to promote parameters to a best common type.

BestCommonAny

Represent’s Postgres’ “anycompatible”-type polymorphic resolution.

Selection of the common type considers the actual types of anycompatible and anycompatiblenonarray inputs, the array element types of anycompatiblearray inputs, the range subtypes of anycompatiblerange inputs, and the multirange subtypes of anycompatiblemultirange inputs. If anycompatiblenonarray is present then the common type is required to be a non-array type. Once a common type is identified, arguments in anycompatible and anycompatiblenonarray positions are automatically cast to that type, and arguments in anycompatiblearray positions are automatically cast to the array type for that type.

For details, see https://www.postgresql.org/docs/current/extend-type-system.html#EXTEND-TYPES-POLYMORPHIC

BestCommonList

Represents polymorphic compatibility operations for Materialize LIST types. This differs from PG’s “anycompatible” type resolution, which focuses on determining a common type, and e.g. using that as AnyCompatibleArray’s element type. Instead, our list compatibility focuses on finding a common list type, and then casting ListElementAnyCompatible parameters to that list type’s elements. This approach is necessary to let us polymorphically resolve custom list types without losing their OIDs.

BestCommonMap

Represents an operation similar to LIST compatibility, but for MAP. This is distinct from BestCommonList in as much as the parameter types that work with BestCommonList are incommensurate with the parameter types used with BestCommonMap.

StructuralEq

Represents type resolution for ScalarType::Record types, which e.g. ignores custom types and type modifications.

In PG, this is handled by invocation of the function calls that take RecordAny params, which we want to avoid if at all possible.

Implementations

impl PolymorphicCompatClass

fn compatible( &self, ecx: &ExprContext<'_>, from: &ScalarType, to: &ScalarType, ) -> bool

Trait Implementations

impl Debug for PolymorphicCompatClass

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Ord for PolymorphicCompatClass

fn cmp(&self, other: &PolymorphicCompatClass) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for PolymorphicCompatClass

fn eq(&self, other: &PolymorphicCompatClass) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for PolymorphicCompatClass

fn partial_cmp(&self, other: &PolymorphicCompatClass) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl TryFrom<&ParamType> for PolymorphicCompatClass

type Error = ()

The type returned in the event of a conversion error.

fn try_from(param: &ParamType) -> Result<PolymorphicCompatClass, Self::Error>

Performs the conversion.

impl Eq for PolymorphicCompatClass

impl StructuralPartialEq for PolymorphicCompatClass