Enum Element 

pub enum Element {
    Alt(Vec<Element>),
    Concat(Vec<Element>),
    Repeat {
        repeat: Repeat,
        body: Box<Element>,
        span: Ignored<Span>,
    },
    Optional(Box<Element>),
    RuleRef {
        name: RuleName,
        span: Ignored<Span>,
    },
    CharVal(CharVal),
    NumVal {
        value: NumVal,
        span: Ignored<Span>,
    },
    ProseVal {
        text: String,
        span: Ignored<Span>,
    },
}

An element of a rule body, in the syntactic layer.

Variants

Alt(Vec<Element>)

a / b / c. Unordered (SCOPE.md 2, goal 2).

Concat(Vec<Element>)

a b c.

Repeat

2*5a.

Fields

repeat: Repeat

The bounds.

body: Box<Element>

The repeated element.

span: Ignored<Span>

Where the bounds sit in the source, for InvalidRepeatRange.

Optional(Box<Element>)

[a].

Kept distinct from Repeat { 0, Some(1) } — which canonicalization rewrites into it — so that Display prints [a] without inspecting bounds, and so that the generator can treat it as the two-branch alternation a / empty for coverage.

RuleRef

A reference to another rule.

Fields

name: RuleName

The referenced name.

span: Ignored<Span>

Where the reference sits in the source.

CharVal(CharVal)

A quoted string terminal.

NumVal

A numeric terminal.

Fields

value: NumVal

The value.

span: Ignored<Span>

Where it sits in the source, for InvalidNumericRange.

ProseVal

<prose>: parsed and preserved, never matched or generated (SCOPE.md 6.5).

Fields

text: String

The text between the angle brackets.

span: Ignored<Span>

Where the prose value sits in the source.

Trait Implementations

impl Clone for Element

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Element

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

Formats the value using the given formatter.

impl Display for Element

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

Formats the value using the given formatter.

impl Eq for Element

impl PartialEq for Element

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Element