Struct ExprEngineBuilder 

pub struct ExprEngineBuilder { /* private fields */ }

Builds an ExprEngine.

Defaults to OperatorFamily::Core (and OperatorFamily::Secret) only. Select optional operator families at runtime with family, families or all_operators.

Implementations

impl ExprEngineBuilder

pub fn family(self, family: OperatorFamily) -> Self

Enables one built-in OperatorFamily.

Enabling a family is not a no-op for existing workflows: under templating mode an unknown operator name passes through as literal data, so {"length": ...} starts evaluating once OperatorFamily::ExtString is enabled ({"$length": ...} pins the literal). OperatorFamily::Datetime and OperatorFamily::Tensor also require their cargo features (datetime, tensor) to be enabled.

pub fn families( self, families: impl IntoIterator<Item = OperatorFamily>, ) -> Self

Enables each built-in OperatorFamily in families.

pub fn all_operators(self) -> Self

Enables the standard optional operator families: ExtString, ExtArray, ExtMath, ExtControl, ExtObject, ErrorHandling, and (when the datetime cargo feature is enabled) Datetime.

OperatorFamily::Tensor is deliberately left out: names like shape, full, cast and concat are ordinary JSON keys, which a live operator would start evaluating.

pub fn operator( self, name: impl Into<String>, op: impl CustomOperator + 'static, ) -> Self

Registers a custom operator, neither scoping nor deterministic.

Dependency

op is a datalogic_rs::CustomOperator, named through this crate’s re-export. It is part of the committed dependency surface, as OwnedDataValue is: wrapping it would still take datalogic’s value and arena types, so the engine keeps the trait itself.

pub fn operator_with( self, info: Operator, op: impl CustomOperator + 'static, ) -> Self

Registers a custom operator with its own flags. The family is always OperatorFamily::Custom; op is a datalogic_rs::CustomOperator, the committed dependency type operator documents.

pub fn secrets(self, secrets: Secrets) -> Self

Sets the secrets the secret operator reads.

pub fn ops_budget(self, ops: u64) -> Self

Sets the ceiling on operations per evaluation.

pub fn build(self) -> Result<ExprEngine>

Builds the engine, with OperatorFamily::Core, OperatorFamily::Secret and the families selected on this builder, and no other. ErrorKind::Config when OperatorFamily::Custom or an uncompiled cargo-feature family (Datetime, Tensor) is requested, or when a custom operator is named secret, is named like a built-in operator of the selected families, or is registered twice.

Trait Implementations

impl Debug for ExprEngineBuilder

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

The selected families, the custom operators’ names and the secrets, redacted.

impl Default for ExprEngineBuilder

fn default() -> Self

Returns the “default value” for a type.