Enum Mode 

pub enum Mode {
    Development,
    Release,
}

Which build a runtime module is being emitted for — spec §16.3.1’s “ships nothing it does not use”, applied to the checks themselves.

Why there are two builds at all

Several of the defects this repository has found were invisible to every static pass and visible only in an emitted program’s answer: a durable Map serialised to {} (#204), a switch fell through. A runtime that checks its own invariants is where that class is caught next time. But a check that runs in production is a check a reader downloads and pays for on every event, and the size gate in crates/zdc-bench/tests/scaling.rs is measured in single-digit bytes of headroom — so an assertion that could not be removed would have to be argued against on size, one at a time, forever.

So the assertions are marked and the release build removes them. What makes that safe rather than a second source of truth is the marker’s shape: it delimits whole lines, so what a release build ships is a subsequence of the lines a developer reads and tests, and the_release_runtime_still_passes_the_suite in tests/render.rs runs the stripped source through the same suite as the unstripped one.

Variants

Development

Keep the assertions. zdc dev builds this.

Release

Remove them. zdc build builds this, and it is the default, because the failure that costs a reader bytes must be the one that takes an explicit decision to cause.

Trait Implementations

impl Clone for Mode

fn clone(&self) -> Mode

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Mode

impl Debug for Mode

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

Formats the value using the given formatter.

impl Default for Mode

fn default() -> Mode

Returns the “default value” for a type.

impl Eq for Mode

impl PartialEq for Mode

fn eq(&self, other: &Mode) -> bool

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Mode