Type Alias ScopeFn 

pub type ScopeFn = Box<dyn Fn(&str, &mut DynSegment, usize, SourceSpan) -> Result<bool> + Send + Sync>;

A scope function that attempts to resolve and apply an operation.

Receives the operation name, the segment, the number of operands on top of the stack, and the source span of the expression. The scope may call segment.peek_stack_infos(num_operands) to inspect types. Returns Ok(true) if handled, Ok(false) if not found, or Err on error.

Error messages returned by scope functions surface verbatim to the user. They should be lowercase, end without a period, and wrap identifiers and type names in backticks.

Aliased Type

pub struct ScopeFn(/* private fields */);