Trait ScalarFnLookup 

pub trait ScalarFnLookup {
    // Required method
    fn call_scalar(
        &self,
        name: &str,
        args: &[Value],
    ) -> Option<Result<Value, ExecutionError>>;
}

Trait for resolving unknown scalar functions at evaluation time.

Implemented for () (no-op) and for PluginRegistry<dyn ScalarFunction> when the plugin feature is enabled.

Required Methods

fn call_scalar( &self, name: &str, args: &[Value], ) -> Option<Result<Value, ExecutionError>>

Try to call a scalar function by name with the given arguments.

Returns None if the function is not found, allowing the caller to produce a default “unknown function” error.

Implementations on Foreign Types

impl ScalarFnLookup for ()

No-op implementation: always returns None (function not found).

fn call_scalar( &self, _name: &str, _args: &[Value], ) -> Option<Result<Value, ExecutionError>>

impl ScalarFnLookup for PluginRegistry<dyn ScalarFunction>

Available on crate feature plugin only.

fn call_scalar( &self, name: &str, args: &[Value], ) -> Option<Result<Value, ExecutionError>>

Implementors