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 “this is a stub waiting for B2/B3/etc.” from real failures once implementations land.

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, the body is coming in a follow-up issue.”

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. Implementations land in follow-up issues; today nothing surfaces this variant.

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.