Enum Error 

pub enum Error {
    RegionNotFound(String),
    ValidationFailed(String),
    TokenBudgetExceeded {
        used: usize,
        max: usize,
    },
    RegionFull {
        region: String,
        used: usize,
        max: usize,
    },
    RegionRefusedWrite {
        region: String,
        reason: String,
    },
    PinnedRegionsOverBudget {
        pinned_tokens: usize,
        total_budget: usize,
    },
    BlueprintInvalid(String),
    LayoutInvalid(String),
    TransformFailed(String),
    SerializationError(Error),
    Other(String),
}

Core error types for Leviath.

Variants

RegionNotFound(String)

Region with the specified name was not found

ValidationFailed(String)

Region validation failed

TokenBudgetExceeded

Content exceeds region’s token budget

Fields

used: usize

Tokens the write would have brought the region to.

max: usize

The region’s ceiling.

RegionFull

A region under admission = "reject" is full, and the write was refused rather than something else being dropped to fit it.

Distinct from Error::TokenBudgetExceeded because the remedy is different: that one says this single write is too big for the region, this one says the region is full and the agent has to decide what it is finished with.

Fields

region: String

The region that refused the write.

used: usize

Tokens the region currently holds.

max: usize

The region’s ceiling.

RegionRefusedWrite

A custom region’s on_write hook rejected the write.

Only raised for agent-origin writes (context_write, context_append, routed tool results), where the refusal and its reason can be reported back to the writer. A framework write that a hook rejects is stored unchanged with a warning instead - a script must not be able to delete an assistant turn or a system record.

Fields

region: String

The region whose hook refused the write.

reason: String

Why, as the hook said it (or a generic phrase when it only returned false).

PinnedRegionsOverBudget

Pinned regions alone exceed total token budget

Fields

pinned_tokens: usize

Tokens held by regions that can never be evicted, which is what makes this unrecoverable rather than a matter of dropping something.

total_budget: usize

The whole window’s budget.

BlueprintInvalid(String)

Blueprint validation failed

LayoutInvalid(String)

Layout validation failed

TransformFailed(String)

Context transform failed

SerializationError(Error)

Serialization error

Other(String)

Generic error

Trait Implementations

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Error for Error

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<Error> for Error

fn from(source: Error) -> Self

Converts to this type from the input type.