Struct SigConstraint 

pub struct SigConstraint {
    pub kw: ConstraintTok,
    pub tyvar: TypeVarTok,
    pub cons: ConsTok,
    pub kind: RecordKind,
}

One constrnt: constraint 'a :: (| l1 : ty1; l2 : ty2; … |) (parser.mly:526-530), a per-item suffix binding that item’s type variable to a row-kind obligation — not a standalone SigItem (a reader expecting the latter should see this doc: upstream attaches constrnts to SigValue/SigDirect/SigType directly, so the suffix form here is the faithful one and avoids an ambiguous “which item does this constrain?”).

Fields

kw: ConstraintTok

tyvar: TypeVarTok

cons: ConsTok

kind: RecordKind

Trait Implementations

impl Clone for SigConstraint

fn clone(&self) -> SigConstraint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SigConstraint

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

Formats the value using the given formatter.

impl<__SyanMacro_Atom> Parse<__SyanMacro_Atom> for SigConstraint

where __SyanMacro_Atom: Spanned + Clone, ConstraintTok: Parse<__SyanMacro_Atom>, TypeVarTok: Parse<__SyanMacro_Atom>, ConsTok: Parse<__SyanMacro_Atom>, RecordKind: Parse<__SyanMacro_Atom>,

type Error = ParseError<<__SyanMacro_Atom as Spanned>::Span>

Every error must be convertible to the universal one, so a field’s failure can become the enclosing type’s failure with no per-field where-predicate. Stating it HERE rather than at each derived impl is what keeps it out of the obligation graph: a per-field <FieldTy as Parse<Atom>>::Error: Into<…> predicate re-creates a projection cycle on a recursive field (E0275), which decycle’s bound-peeling does not break.

fn parse_stream<__SyanMacro_S: ParseStream<Atom = __SyanMacro_Atom>>( __syan_stream: &mut __SyanMacro_S, ) -> Result<Self, Self::Error>

Parse from a reborrowable stream.

fn parse(stream: impl IntoParseStream<Atom = Atom>) -> Result<Self, Self::Error>

Parse from anything that can become a stream — String, TokenStream, an existing stream.

fn attempt(self) -> Attempt<Self>

Wrap this value in Attempt, the atomic-parse marker: parsing an Attempt<Self> parses Self but rewinds the stream on failure (it requires Atom: Clone). This is the value constructor; value.attempt() is sugar for Attempt(value).

impl PartialEq for SigConstraint

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SigConstraint

impl<__SyanMacro_Atom> Unparse<__SyanMacro_Atom> for SigConstraint

where ConstraintTok: Unparse<__SyanMacro_Atom>, TypeVarTok: Unparse<__SyanMacro_Atom>, ConsTok: Unparse<__SyanMacro_Atom>, RecordKind: Unparse<__SyanMacro_Atom>,

fn unparse<__Syan_Emitter: Emitter<__SyanMacro_Atom>>( &self, __syan_sink: &mut __Syan_Emitter, ) -> Result<(), <__Syan_Emitter as Emitter<__SyanMacro_Atom>>::Error>