Enum Pattern 

pub enum Pattern {
    Literal(LiteralPattern),
    Wildcard,
    Binding(String),
    EnumVariant {
        namespace: Option<String>,
        type_name: String,
        variant: String,
        payload: VariantPatternPayload,
    },
    Struct {
        namespace: Option<String>,
        type_name: String,
        fields: Vec<(String, Pattern)>,
        rest: bool,
    },
    Array {
        elements: Vec<Pattern>,
        rest: Option<ArrayRest>,
    },
    Or(Vec<Pattern>),
}

A pattern appears in match arms (phase 4 introduces this; future phases may reuse it in let destructuring and fn params). Structurally mirrors the runtime Value enum so each variant’s matcher reads as “does this value fit here?”.

Variants

Literal(LiteralPattern)

Matches a specific value verbatim: 1, "foo", true, false, none.

Wildcard

_ — matches anything, binds nothing.

Binding(String)

Bare identifier — matches anything, binds the value to this name for the arm’s body.

EnumVariant

Type::Variant / Type::Variant(...) / Type::Variant { ... }, optionally namespaced via ns.Type::Variant(...).

Fields

namespace: Option<String>

type_name: String

variant: String

payload: VariantPatternPayload

Struct

Type { field: pat, field, .. } destructures a struct, optionally namespaced via ns.Type { ... }.

Fields

namespace: Option<String>

type_name: String

fields: Vec<(String, Pattern)>

rest: bool

Array

[a, b, ..rest] destructures an array.

Fields

elements: Vec<Pattern>

rest: Option<ArrayRest>

Or(Vec<Pattern>)

p1 | p2 | p3 — match if any alternative matches. Every alternative must introduce the same set of bindings.

Trait Implementations

impl Clone for Pattern

fn clone(&self) -> Pattern

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Pattern

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

Formats the value using the given formatter.