Struct Surface 

pub struct Surface { /* private fields */ }

The surface environment: a stack of scopes, innermost last.

Implementations

impl Surface

pub fn new() -> Surface

A surface with nothing declared. The parse path it produces is byte-identical to having no surface at all, which is what keeps the extension point free when nobody uses it.

pub fn namespaces(&self) -> &Namespaces

The namespace scope: what is current, what is open.

pub fn namespaces_mut(&mut self) -> &mut Namespaces

The namespace scope, to push and wind back a SCOPED opening — Open … in <command>, and a declaration whose own name names the namespace it is written into.

pub fn enter_declaration(&mut self, declared: &Name) -> (String, ScopeMark)

Enter the scope a DECLARATION named declared elaborates in, and give back the absolute key it declares. See Namespaces::enter_declaration; this is the door, because only the surface knows how deep the section stack is, and that is what orders the two scope stacks.

pub fn is_empty(&self) -> bool

Is anything declared? A surface with no notations and no macros is skipped entirely.

pub fn section_depth(&self) -> usize

How many SECTIONS are open. The root scope is never pushed and never popped, so it is not one of them.

pub fn section_names(&self) -> Vec<String>

The open sections, outermost first \u{2014} what a document must close before it ends. An anonymous section is named AS one rather than as the empty string, so an unbalanced document reports something a reader can act on.

pub fn close_sections_to(&mut self, depth: usize)

Close every section opened since depth. Only ever SHRINKS: a section already closed took its notations with it and cannot be brought back, which is why an over-closing document is reported rather than silently repaired.

pub fn declare(&mut self, decl: SurfaceDecl) -> Result<(), ParseError>

Apply one surface declaration.

pub fn expand_macros(&self, text: &str) -> Result<String, ParseError>

Rewrite every macro invocation in text until none remains.

Text in, text out, because an alternative may invoke the macro it is defining (nested![$x, $xs] expands to a mycons applied to nested![$xs]) and that inner call can only be matched once its argument is known. The step budget is a hard backstop: a recursive rule that never reaches its base case FAILS rather than hangs.

Trait Implementations

impl Debug for Surface

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

Formats the value using the given formatter.

impl Default for Surface

fn default() -> Surface

Returns the “default value” for a type.