Struct Sandbox 

pub struct Sandbox { /* private fields */ }

A JavaScript sandbox the compiler owns, for running the code it just emitted — spec §17.4.8.

This is the crate’s second job, stated in its own module doc: verifying ZDeceptron must not require a JavaScript toolchain. Build-time evaluation is the same requirement pointed at the user rather than at CI. zdc build therefore evaluates a static signal in process, and a developer who uses the fourth placement still installs one binary and nothing else.

Implementations

impl Sandbox

pub fn new() -> Sandbox

pub fn load(&mut self, module: &str) -> Result<(), RuntimeError>

Evaluate a module in the sandbox, keeping its bindings for later questions.

export is stripped rather than honoured: the engine’s module loader wants a filesystem resolver, and a module evaluated as a script leaves its top-level consts where a following eval can see them — which is exactly the interface wanted here.

pub fn provide( &mut self, root: &Path, capabilities: &[Capability], ) -> Result<(), RuntimeError>

Install the capabilities the code being run may ask the compiler for, as $build.<name>(argument).

This is the whole of the build-time FFI, and its shape is the argument for it. A capability is a Rust function pointer with a fixed signature, resolved against root before it is answered. Nothing is imported, nothing is resolved from a registry, and nothing outside root is reachable — which a module loader could promise none of.

root is passed to each answer rather than baked into it so the sandbox boundary is one value, checked in one place, and visible in every capability’s signature.

pub fn text(&mut self, expression: &str) -> Result<String, RuntimeError>

Evaluate an expression and return its value as text.

String(value), not the engine’s debug rendering: a string comes back as itself, so a caller that asked for JSON.stringify(x) gets the JSON and a caller that asked for a file’s contents gets the contents. There is no framing anywhere in this interface, because one question returns one answer.

Trait Implementations

impl Default for Sandbox

Available on crate feature evaluate only.

fn default() -> Sandbox

Returns the “default value” for a type.