Enum UndefinedBehavior

#[non_exhaustive]
pub enum UndefinedBehavior {
    Lenient,
    Chainable,
    Strict,
}

Defines the behavior of undefined values in the engine.

At present there are three types of behaviors available which mirror the behaviors that Jinja2 provides out of the box.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Lenient

The default, somewhat lenient undefined behavior.

• printing: allowed (returns empty string)
• iteration: allowed (returns empty array)
• attribute access of undefined values: fails

Chainable

Like Lenient, but also allows chaining of undefined lookups.

• printing: allowed (returns empty string)
• iteration: allowed (returns empty array)
• attribute access of undefined values: allowed (returns undefined)

Strict

Complains very quickly about undefined values.

• printing: fails
• iteration: fails
• attribute access of undefined values: fails

Trait Implementations

impl Clone for UndefinedBehavior

fn clone(&self) -> UndefinedBehavior

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for UndefinedBehavior

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

Formats the value using the given formatter.

impl Default for UndefinedBehavior

fn default() -> UndefinedBehavior

Returns the “default value” for a type.

impl PartialEq for UndefinedBehavior

fn eq(&self, other: &UndefinedBehavior) -> 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 Copy for UndefinedBehavior

impl Eq for UndefinedBehavior

impl StructuralPartialEq for UndefinedBehavior