Enum Param 

pub enum Param {
    Optional {
        q: OptionalTok,
        name: VarTok,
    },
    Pat(PatBot),
    Bundled {
        opts: CstOptBinders,
        body: PatBot,
    },
}

One curried parameter of an ordinary (non-let-rec) let, or of a let-inline/let-block/let-math command binding — upstream’s arg nonterminal (nxnonrecdec’s argpart/cmdarglst, parser.mly:622-624: arg: patbot | OPTIONAL defedvar): a full pattern, or the def-site optional-parameter marker ?:name (parser.mly’s OPTIONAL vartok), e.g. stdja.satyh’s let document record ?:configopt inner = .. and annot.satyh’s let-inline ctx \href ?:borderopt uri inner = ... Upstream’s let-rec/fun argument grammar (recdecargpart/argpats — RecBinding/AndBinding/Expr::Fun) has no such alternative, only plain let and the three command-binding forms do — all four keep Vec<Param> (super::TopLet, Expr::LetIn, super::TopBinding::LetInline/LetBlock/LetMath, Expr::LetMathIn). Elaborated (elaborate.rs) by widening Optional to PatBot::Var (params_to_patbots) before the ordinary pattern-currying machinery runs (plain let’s rec_clause_value, or a command binding’s curry_cmd_params) — the ?: marker carries no further semantics of its own in this port (typecheck.rs’s command_scheme doc comment: optionality is inferred structurally, not from this marker); for a command binding, the maximal leading run of ?:-marked params is additionally counted by elaborate.rs’s leading_optional_count and recorded into the binding’s Scope::optional_arity, so a marker-less call site can auto-omit those slots (see cmd_args/math_bot’s Cmd arm).

Variants

Optional

Fields

q: OptionalTok

name: VarTok

Pat(PatBot)

Bundled

A SATySFi 0.1 ?(l = x, …) labeled-optional command-parameter bundle, lowered from cst_v1::Param { opts: Some(_), body } by v1/lower.rs::lower_command_params. Reuses CstOptBinders verbatim (the same node a value-level fun ?(l = x) p -> .. bundle lowers to) — ?(-headed, so distinct from the 0.0.6 ?:-headed Param::Optional above (no arm overlap, no grammar ambiguity: this variant is never PARSED directly by this 0.0.6-frozen cst.rs, only ever constructed by the 0.1 lowering path). Consumed by elaborate.rs’s bundle-aware curry_cmd_params_v1, which emits Ast::LambdaOpt for it — see that function’s doc comment.

Fields

opts: CstOptBinders

body: PatBot

Trait Implementations

impl Clone for Param

fn clone(&self) -> Param

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Param

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

Formats the value using the given formatter.

impl<__SyanMacro_Atom> Parse<__SyanMacro_Atom> for Param

where __SyanMacro_Atom: Spanned + Clone, OptionalTok: Parse<__SyanMacro_Atom>, VarTok: Parse<__SyanMacro_Atom>, PatBot: Parse<__SyanMacro_Atom>, CstOptBinders: 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 Param

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Param

impl<__SyanMacro_Atom> Unparse<__SyanMacro_Atom> for Param

where OptionalTok: Unparse<__SyanMacro_Atom>, VarTok: Unparse<__SyanMacro_Atom>, PatBot: Unparse<__SyanMacro_Atom>, CstOptBinders: Unparse<__SyanMacro_Atom>,

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