Enum HostlibError 

pub enum HostlibError {
    Unimplemented {
        builtin: &'static str,
    },
    MissingParameter {
        builtin: &'static str,
        param: &'static str,
    },
    InvalidParameter {
        builtin: &'static str,
        param: &'static str,
        message: String,
    },
    Backend {
        builtin: &'static str,
        message: String,
    },
}

All errors a hostlib builtin can surface.

Variants intentionally describe the kind of failure rather than the specific module — every module routes its missing-implementation errors through HostlibError::Unimplemented so embedders and tests can distinguish intentionally scaffolded contracts from runtime failures.

Variants

Unimplemented

The method exists in the registration table but has no implementation yet. This is the canonical scaffold-stage error: it tells callers “the contract is stable, but this module has not been implemented.”

Fields

builtin: &'static str

Fully-qualified builtin name, e.g. "hostlib_ast_parse_file".

MissingParameter

A required parameter was missing from the call payload.

Fields

builtin: &'static str

Fully-qualified builtin name.

param: &'static str

Name of the missing parameter.

InvalidParameter

A parameter was present but had the wrong shape (wrong type, malformed).

Fields

builtin: &'static str

Fully-qualified builtin name.

param: &'static str

Name of the invalid parameter.

message: String

Human-readable description of the violation.

Backend

Catch-all wrapper for I/O, parsing, or other backend failures.

Fields

builtin: &'static str

Fully-qualified builtin name.

message: String

Human-readable failure description.

Implementations

impl HostlibError

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

The fully-qualified builtin name this error came from. Useful for embedder logging and for the routing tests in tests/.

Trait Implementations

impl Debug for HostlibError

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

Formats the value using the given formatter.

impl Display for HostlibError

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

Formats the value using the given formatter.

impl Error for HostlibError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<HostlibError> for VmError

fn from(err: HostlibError) -> VmError

Converts to this type from the input type.