Struct ExLine 

pub struct ExLine { /* private fields */ }

The : line — its text and the caret editing it, as ONE value.

They are one value because they have an invariant between them — caret <= text.chars().count() — and a struct with private fields is the only place an invariant like that can be maintained once rather than at every mutation site.

That is not a hypothetical. The first version of the ex-line caret kept the two as sibling fields of the enum variant, and clear_minibuffer emptied the text while leaving the caret where it was. No test could see it, because a caret past the end is silently clamped by Ruler instead of panicking — the only report was warning: unused variable: caret, which is the compiler saying “you destructured the invariant’s other half and did nothing with it”.

Wire shape

#[serde(flatten)]ed into ModalState::Command, and text is renamed to minibuffer, so the published schema is unchanged by this refactor: {"mode": "Command", "minibuffer": "wq", "caret": 2}. escriba-api publishes it, so the encapsulation is internal only.

Implementations

impl ExLine

pub fn text(&self) -> &str

The text typed so far, without the leading :.

pub const fn caret(&self) -> usize

The caret, in chars from the start.

pub fn len_chars(&self) -> usize

Length in chars — the caret’s upper bound.

pub fn insert(&mut self, ch: char)

Insert a char AT the caret and step past it.

pub fn push_str(&mut self, s: &str)

Append a raw fragment and park the caret at the end.

Appends rather than inserting on purpose: its caller is the command registry’s __quit__ sentinel handshake, which is writing a fragment the user did not type.

pub fn move_caret(&mut self, to: CaretMove)

Move the caret.

pub fn delete(&mut self)

Delete the char AT the caret (<Del>). No-op at the end of the line.

pub fn backspace(&mut self) -> Option<char>

Delete the char BEFORE the caret (<BS>), returning it.

Deleting before the caret and deleting the tail are the same operation only while the caret sits at the end — exactly the assumption that made the search prompt’s shadow diverge from the typed prompt.

pub fn clear(&mut self)

Empty the line AND return the caret home.

Both halves, because they are one value. The version of this that cleared only the text is what motivated the type.

Trait Implementations

impl Clone for ExLine

fn clone(&self) -> ExLine

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ExLine

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

Formats the value using the given formatter.

impl Default for ExLine

fn default() -> ExLine

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ExLine

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for ExLine

impl JsonSchema for ExLine

fn schema_name() -> String

The name of the generated JSON Schema.

fn schema_id() -> Cow<'static, str>

Returns a string that uniquely identifies the schema produced by this type.

fn json_schema(generator: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn is_referenceable() -> bool

Whether JSON Schemas generated for this type should be re-used where possible using the $ref keyword.

impl PartialEq for ExLine

fn eq(&self, other: &ExLine) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for ExLine

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ExLine