Method find_syntax

core/src/callable.rs:673–686

Finds the syntax definition that matches the given argument count. Returns an error if no syntax matches, and panics if multiple syntaxes match (which would indicate an ambiguous callable definition).

(&self, nargs: usize)

    /// Returns an error if no syntax matches, and panics if multiple syntaxes match (which would
    /// indicate an ambiguous callable definition).
    pub(crate) fn find_syntax(&self, nargs: usize) -> Option<&CallableSyntax> {
        let mut matches = self.syntaxes.iter().filter(|s| s.expected_nargs().contains(&nargs));
        let syntax = matches.next();
        match syntax {
            Some(syntax) => {
                debug_assert!(matches.next().is_none(), "Ambiguous syntax definitions");
                if cfg!(debug_assertions) {
                    self.debug_assert_function_seps(syntax);
                }
                Some(syntax)
            }
            None => None,
        }
    }

    /// Gets the callable's category as a collection of lines.  The first line is the title of the
    /// category, and any extra lines are additional information for it.