Enum InformationStatus 

pub enum InformationStatus {
    New,
    Inferrable,
    Evoked,
    Unused,
}

Information status of a discourse entity.

Following Prince (1981) “Toward a Taxonomy of Given-New Information” and Strube’s (1998) hearer-old/hearer-new distinction.

Hearer-Old vs Hearer-New

The key distinction is whether the entity is already in the hearer’s discourse model:

• Hearer-old: Evoked, Unused, Inferrable — the hearer can identify the referent
• Hearer-new: New — introduces a new discourse entity

Hearer-old entities rank higher in the S-list because they are already salient to the hearer.

Example

use anno::discourse::centering::InformationStatus;

// "the man" after "a man walked in" — evoked
assert!(InformationStatus::Evoked.is_hearer_old());

// "a dog" first mention — new
assert!(!InformationStatus::New.is_hearer_old());

// Evoked entities get salience boost
assert!(InformationStatus::Evoked.salience_boost() >
        InformationStatus::New.salience_boost());

Variants

New

First mention, indefinite NP (“a man walked in”). Introduces a new entity to the discourse model.

Inferrable

First explicit mention but inferrable from context. E.g., “the door” after “John entered a room” — the room implies a door.

Evoked

Previously mentioned in discourse (“the man” referring back to “a man”). Most common status for anaphoric expressions.

Unused

Known from world knowledge or situational context. E.g., “the sun”, “the president” — identifiable without prior mention.

Implementations

impl InformationStatus

pub const fn is_hearer_old(&self) -> bool

Is this hearer-old? (Known or inferrable by hearer)

pub const fn salience_boost(&self) -> f64

Salience boost for hearer-old entities.

Strube (1998): “hearer-old entities are ranked higher than hearer-new”

Trait Implementations

impl Clone for InformationStatus

fn clone(&self) -> InformationStatus

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for InformationStatus

impl Debug for InformationStatus

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

Formats the value using the given formatter.

impl Default for InformationStatus

fn default() -> InformationStatus

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for InformationStatus

fn deserialize<__D>( __deserializer: __D, ) -> Result<InformationStatus, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for InformationStatus

impl Hash for InformationStatus

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for InformationStatus

fn eq(&self, other: &InformationStatus) -> 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 Serialize for InformationStatus

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for InformationStatus