Enum Action 

pub enum Action<'g> {
    Shift(StateIndex),
    Reduce(Rule<'g>),
    Halt,
}

An LR action.

Variants

Shift(StateIndex)

Shift the next symbol from the input stream onto the stack. Then enter the give state.

Shift is also used to represent a GOTO transition.

Reduce(Rule<'g>)

Use the given rule to reduce. This pops elements off the stack equal to the number of symbols on the right hand side. These become the children of the parse tree with the left hand side being the root.

Conceptually, this pushes the nonterminal back into the input stream. This will always be followed by applying a Shift action to remove the nonterminal that was just generated off of input stream and back onto the stack.

Halt

The machine successfully consumed the start rule. If there is no more input remaining, the parse was successful.

Trait Implementations

impl<'g> Clone for Action<'g>

fn clone(&self) -> Action<'g>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'g> Debug for Action<'g>

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

Formats the value using the given formatter.

impl<'g> PartialEq for Action<'g>

fn eq(&self, other: &Action<'g>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'g> Copy for Action<'g>

impl<'g> Eq for Action<'g>

impl<'g> StructuralPartialEq for Action<'g>