Enum Operand 

pub enum Operand {
    Unused,
    Word(&'static [Repr]),
    Value,
}

Which of a, b and c an opcode uses, and for what.

This is the table ADR 0041 calls the format’s central saving: “every slot is inside the function frame” is not forty-nine rules but one rule over three fields, driven by which of the three an opcode declares live.

Variants

Unused

The opcode does not use this field, and it must be zero.

Requiring the zero is what makes the encoding canonical: two encodings of one program are byte-identical, and encode(decode(b)) is b.

Word(&'static [Repr])

One word of the frame, holding one of these Reprs.

ANY is the empty list and means the opcode constrains nothing — the destination of a call, whose Repr is the head word of whatever the callee answers, and the operand of an addr.slot, which is any location at all.

Value

The first slot of a value location whose width comes from the layout in the payload.

The check is the fits one crate::verify makes: slot + width must be inside the frame, because a run of words copied off the top of a frame reads or writes the frame above it.

Trait Implementations

impl Clone for Operand

fn clone(&self) -> Operand

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Operand

impl Debug for Operand

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

Formats the value using the given formatter.

impl Eq for Operand

impl PartialEq for Operand

fn eq(&self, other: &Operand) -> 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 StructuralPartialEq for Operand