Enum StagePrefix 

pub enum StagePrefix {
    Next(ExactAmpTok),
    Prev(ExactTildeTok),
}

A staging prefix on a nxunsub operand: &e builds code for the next stage, ~e splices the result of a previous-stage computation (parser.mly:796-797, UTNext/UTPrev).

Upstream spells these as alternatives of nxunsub, alongside the ! deref; this grammar flattens that level, so like minus/excl they become an optional prefix field. The looser shape accepts a few combinations upstream’s grammar does not (&!x), which is the same latitude AppExpr already takes for -!x.

Variants

Next(ExactAmpTok)

&e — quote: the value is e’s code, to run one stage later.

Prev(ExactTildeTok)

~e — splice: run e now and drop its code in here.

Trait Implementations

impl Clone for StagePrefix

fn clone(&self) -> StagePrefix

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StagePrefix

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

Formats the value using the given formatter.

impl<__SyanMacro_Atom> Parse<__SyanMacro_Atom> for StagePrefix

where __SyanMacro_Atom: Spanned + Clone, ExactAmpTok: Parse<__SyanMacro_Atom>, ExactTildeTok: 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 StagePrefix

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for StagePrefix

impl<__SyanMacro_Atom> Unparse<__SyanMacro_Atom> for StagePrefix

where ExactAmpTok: Unparse<__SyanMacro_Atom>, ExactTildeTok: Unparse<__SyanMacro_Atom>,

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