Enum TypeDeclBody 

pub enum TypeDeclBody {
    Variant {
        leading_bar: Option<BarTok>,
        first: VariantDef,
        rest: Vec<BarVariantDef>,
    },
    Synonym(TypeExpr),
}

The right-hand side of a type declaration: either a variant’s constructor list, or (transparently) a type-synonym body. Trying the variant shape first is unambiguous: a type name is always a bare VAR in this grammar (txbot), so no type expression can ever start with the BarTok/CtorTok a variant list requires — any input that isn’t a variant list falls through to Synonym cleanly, exactly like upstream’s nxvariantdec telling variants (always CONSTRUCTOR-headed) apart from txfunc by lookahead.

Variants

Variant

[|] Ctor [of ty] (| Ctor [of ty])*.

Fields

leading_bar: Option<BarTok>

first: VariantDef

rest: Vec<BarVariantDef>

Synonym(TypeExpr)

ty — a transparent type synonym, e.g. type point = length * length (typechecker.ml’s SynonymType/add_synonym: the name is replaced by this body wherever it appears in type position, so it never reaches unification itself). TypeDecl::tyvars is parsed the same way for a synonym as for a variant (type 'a foo = ..), but only the zero-param case can actually be referenced anywhere today — this grammar has no applied-type-constructor syntax (TypeAtom’s doc comment) to spell a synonym’s argument at a use site.

Trait Implementations

impl Clone for TypeDeclBody

fn clone(&self) -> TypeDeclBody

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TypeDeclBody

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

Formats the value using the given formatter.

impl<__SyanMacro_Atom> Parse<__SyanMacro_Atom> for TypeDeclBody

where __SyanMacro_Atom: Spanned + Clone, Option<BarTok>: Parse<__SyanMacro_Atom>, VariantDef: Parse<__SyanMacro_Atom>, Vec<BarVariantDef>: Parse<__SyanMacro_Atom>, TypeExpr: 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 TypeDeclBody

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for TypeDeclBody

impl<__SyanMacro_Atom> Unparse<__SyanMacro_Atom> for TypeDeclBody

where Option<BarTok>: Unparse<__SyanMacro_Atom>, VariantDef: Unparse<__SyanMacro_Atom>, Vec<BarVariantDef>: Unparse<__SyanMacro_Atom>, TypeExpr: Unparse<__SyanMacro_Atom>,

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