Enum syn::Pat

#[non_exhaustive]
pub enum Pat {
    Box(PatBox),
    Ident(PatIdent),
    Lit(PatLit),
    Macro(PatMacro),
    Or(PatOr),
    Path(PatPath),
    Range(PatRange),
    Reference(PatReference),
    Rest(PatRest),
    Slice(PatSlice),
    Struct(PatStruct),
    Tuple(PatTuple),
    TupleStruct(PatTupleStruct),
    Type(PatType),
    Verbatim(TokenStream),
    Wild(PatWild),
}

A pattern in a local binding, function signature, match expression, or various other places.

This type is available only if Syn is built with the "full" feature.

Syntax tree enum

This type is a syntax tree enum.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Box(PatBox)

A box pattern: box v.

Ident(PatIdent)

A pattern that binds a new variable: ref mut binding @ SUBPATTERN.

Lit(PatLit)

A literal pattern: 0.

This holds an Expr rather than a Lit because negative numbers are represented as an Expr::Unary.

Macro(PatMacro)

A macro in pattern position.

Or(PatOr)

A pattern that matches any one of a set of cases.

Path(PatPath)

A path pattern like Color::Red, optionally qualified with a self-type.

Unqualified path patterns can legally refer to variants, structs, constants or associated constants. Qualified path patterns like <A>::B::C and <A as Trait>::B::C can only legally refer to associated constants.

Range(PatRange)

A range pattern: 1..=2.

Reference(PatReference)

A reference pattern: &mut var.

Rest(PatRest)

The dots in a tuple or slice pattern: [0, 1, ..]

Slice(PatSlice)

A dynamically sized slice pattern: [a, b, ref i @ .., y, z].

Struct(PatStruct)

A struct or struct variant pattern: Variant { x, y, .. }.

Tuple(PatTuple)

A tuple pattern: (a, b).

TupleStruct(PatTupleStruct)

A tuple struct or tuple variant pattern: Variant(x, y, .., z).

Type(PatType)

A type ascription pattern: foo: f64.

Verbatim(TokenStream)

Tokens in pattern position not interpreted by Syn.

Wild(PatWild)

A pattern that matches any value: _.

Trait Implementations

impl From<PatBox> for Pat

fn from(e: PatBox) -> Pat

Converts to this type from the input type.

impl From<PatIdent> for Pat

fn from(e: PatIdent) -> Pat

Converts to this type from the input type.

impl From<PatLit> for Pat

fn from(e: PatLit) -> Pat

Converts to this type from the input type.

impl From<PatMacro> for Pat

fn from(e: PatMacro) -> Pat

Converts to this type from the input type.

impl From<PatOr> for Pat

fn from(e: PatOr) -> Pat

Converts to this type from the input type.

impl From<PatPath> for Pat

fn from(e: PatPath) -> Pat

Converts to this type from the input type.

impl From<PatRange> for Pat

fn from(e: PatRange) -> Pat

Converts to this type from the input type.

impl From<PatReference> for Pat

fn from(e: PatReference) -> Pat

Converts to this type from the input type.

impl From<PatRest> for Pat

fn from(e: PatRest) -> Pat

Converts to this type from the input type.

impl From<PatSlice> for Pat

fn from(e: PatSlice) -> Pat

Converts to this type from the input type.

impl From<PatStruct> for Pat

fn from(e: PatStruct) -> Pat

Converts to this type from the input type.

impl From<PatTuple> for Pat

fn from(e: PatTuple) -> Pat

Converts to this type from the input type.

impl From<PatTupleStruct> for Pat

fn from(e: PatTupleStruct) -> Pat

Converts to this type from the input type.

impl From<PatType> for Pat

fn from(e: PatType) -> Pat

Converts to this type from the input type.

impl From<PatWild> for Pat

fn from(e: PatWild) -> Pat

Converts to this type from the input type.

impl Parse for Pat

fn parse(input: ParseStream<'_>) -> Result<Self>