Enum RecordingBackend 

pub enum RecordingBackend {
    Ast,
    Vm,
}

Which backend produced a recording.

A trace is written by cove run --trace, by a built binary, and by a benchmark, and all of them run a program on one of the evaluators this toolchain has. The header names which, so that cove replay can run the recording on the backend that made it without inferring anything, and can say so when it was told to do otherwise. ADR 0026 is the decision and its reasoning.

A closed set rather than free text, spelled with the names --backend accepts, so a reader that meets an unknown name refuses the file rather than carrying a string it cannot act on.

Variants

Ast

The tree-walking interpreter, which ADR 0012 keeps as the oracle.

Vm

The linear-memory backend of ADR 0034, which is what runs a program.

Between ADR 0034’s cutover and the rename that followed it, this backend was spelled lvm here, and a trace recorded in that window says so. Such a file is not read: RecordingBackend::parse refuses lvm the way it refuses any other name, and cove replay reports it as a header it cannot read. That is the trade issue #240 took deliberately when it chose to delete the predecessor first and rename second — the window is measured in commits, the format version had already moved to 4 in the same cutover, and a trace is a recording of a run that can be taken again. Nothing was built to accept the old spelling: an alias would make a name that is scheduled to mean nothing readable forever.

Implementations

impl RecordingBackend

pub fn as_str(self) -> &'static str

The name this backend is written under in a trace header, which is also the name --backend accepts for it.

pub fn parse(text: &str) -> Option<RecordingBackend>

Parses the name RecordingBackend::as_str produces.

Trait Implementations

impl Clone for RecordingBackend

fn clone(&self) -> RecordingBackend

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for RecordingBackend

impl Debug for RecordingBackend

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

Formats the value using the given formatter.

impl Display for RecordingBackend

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

Formats the value using the given formatter.

impl Eq for RecordingBackend

impl PartialEq for RecordingBackend

fn eq(&self, other: &RecordingBackend) -> 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 RecordingBackend