Struct mz_sql::func::PolymorphicSolution

pub(crate) struct PolymorphicSolution {
    compat: Option<PolymorphicCompatClass>,
    seen: Vec<CoercibleScalarType>,
    key: Option<ScalarType>,
}

Represents a solution to a set of polymorphic constraints, expressed as the params of a function and the user-supplied args.

Fields

compat: Option<PolymorphicCompatClass>

Constrains this solution to a particular form of polymorphic compatibility.

seen: Vec<CoercibleScalarType>

key: Option<ScalarType>

An internal representation of the discovered polymorphic type.

Implementations

impl PolymorphicSolution

fn new( ecx: &ExprContext<'_>, args: &[CoercibleScalarType], params: &ParamList, ) -> Option<PolymorphicSolution>

Provides a solution to the polymorphic type constraints expressed in params based on the users’ input in args. Returns None if a solution cannot be found.

After constructing the PolymorphicSolution, access its solution using PolymorphicSolution::target_for_param_type.

fn track_seen(&mut self, param: &ParamType, seen: CoercibleScalarType)

Determines the desired type of polymorphic compatibility, as well as the values to determine a polymorphic solution.

fn determine_key(&mut self, ecx: &ExprContext<'_>) -> bool

Attempt to resolve all polymorphic types to a single “key” type. For target_for_param_type to be useful, this must have already been called.

fn target_for_param_type(&self, param: &ParamType) -> Option<ScalarType>

Trait Implementations

impl Debug for PolymorphicSolution

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

Formats the value using the given formatter.