Struct MacroEngine 

pub struct MacroEngine<'a> {
    pub spec: CommandSpec,
    pub reading_macro: Vec<MacroNode<'a>>,
    pub scanned_tokens: Vec<(Token, &'a str)>,
    /* private fields */
}

MacroEngine has exact same interface as Lexer, but it expands macros.

When it meets a macro in token stream, It evaluates a macro into expanded tokens.

Fields

spec: CommandSpec

Command specification

reading_macro: Vec<MacroNode<'a>>

Macro stack

scanned_tokens: Vec<(Token, &'a str)>

Toekns used by macro stack

Implementations

impl<'a> MacroEngine<'a>

pub fn new(spec: CommandSpec) -> Self

Create a new macro engine

pub fn create_scope(&mut self) -> (Snapshot,)

Create a new scope for macro definitions

pub fn restore(&mut self, (snapshot): (Snapshot,))

Restore the scope (delete all macros defined in the child scope)

pub fn add_macro(&mut self, name: &'a str, value: Macro<'a>)

Peek the next token and its text

Trait Implementations

impl<'a> MacroifyStream<'a> for MacroEngine<'a>

fn get_macro(&self, name: &str) -> Option<Macro<'a>>

Get a macro by name (if meeted in the stream)

impl<'a> TokenStream<'a> for MacroEngine<'a>

fn bump(&mut self, ctx: &mut StreamContext<'a>)

Bump the token stream with at least one token if possible