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BindingDecl

Struct BindingDecl 

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pub struct BindingDecl {
    pub outputs: Vec<(String, ExprSpan)>,
    pub destructure: bool,
    pub body: Expr,
    pub leading_comment: Option<Comment>,
    pub trailing_line_comment: Option<Comment>,
    pub blank_line_before: bool,
    pub span: ExprSpan,
}
Expand description

binding = binding_target ":=" expression ";". binding_target = identifier | "(" identifier { "," identifier } [ "," ] ")".

Unlike the old method_decl this replaces, a binding names no explicit input cell list — its inputs are whichever already-declared cells body references, deduced at compile time (see crate::parser::AdamParser::parse_deduced_expr); this untyped CST parser has no cell declarations to resolve against, so it records no input list at all, only the outputs.

Parenthesizing the left-hand side requests tuple destructuring, matching Rust’s tuple-pattern syntax: (a, b) := ... and the single-element (a,) := ... (trailing comma mandatory, exactly as in a Rust 1-tuple pattern) both destructure body’s tuple result element-wise into outputs. A bare identifier, or a single parenthesized identifier with no comma ((a) := ..., mere grouping), binds body’s whole result directly to that one output instead — see Self::destructure.

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§outputs: Vec<(String, ExprSpan)>

The binding’s output cell names (the left-hand side), in declaration order.

§destructure: bool

Whether the left-hand side requests destructuring ((a, b) := ... or (a,) := ...) as opposed to a direct bind (a := ... or the equivalent grouping (a) := ...). Always true when outputs.len() > 1; when outputs.len() == 1, distinguishes “destructure this single-element tuple” from “bind this whole value directly” — a distinction the parenthesized-or-not left-hand side is the only way to express, since both forms name exactly one output.

§body: Expr

The parsed right-hand-side expression.

§leading_comment: Option<Comment>

A leading comment immediately preceding this binding, if recovered by crate::trivia::attach_trivia.

§trailing_line_comment: Option<Comment>

A ////* */ comment on the same source line as this binding’s own last token, if recovered by crate::trivia::attach_trivia. See https://github.com/stlab/cel-rs/issues/59.

§blank_line_before: bool

Whether a blank line preceded this binding, if recovered by crate::trivia::attach_trivia.

§span: ExprSpan

The span of the whole a := ...; / (a, b) := ...; declaration.

Trait Implementations§

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impl Clone for BindingDecl

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fn clone(&self) -> BindingDecl

Returns a duplicate of the value. Read more
1.0.0 (const: unstable) · Source§

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

Performs copy-assignment from source. Read more
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impl Debug for BindingDecl

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

Formats the value using the given formatter. Read more

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dest. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.