State.DecodeFailure
luastra/stateState.DecodeFailure represents the unsuccessful branch of a bounded operation. Its stable code and structured context support control flow and safe diagnostics without parsing an exception message.
Before you use it
Add luastra/state to this module's dependencies in luastra.json, then import it with require("luastra/state"). No capability is required for encoding, decoding, or migration. Persistence additionally needs luastra/host plus storage.get and storage.set.
How it fits
The type describes string fields, migration functions, or tagged decode/migration results.
When to use it
Use State.DecodeFailure on the unsuccessful branch of the related result. Read its stable fields for control flow or diagnostics; do not parse human-readable assertion or error text.
Fields or definition
| Parameter | Type / values | Description |
|---|---|---|
| success | false | Discriminator that must be checked before reading branch-specific fields. |
| version | nil | Explicit contract version used to validate or migrate the serialized value. |
| fields | nil | Validated bounded field map carried by the decoded or migrated value. |
| error | DecodeError | Bounded failure information, or nil on the successful branch. |
Error codes
This is the complete closed vocabulary emitted by the named operation in this Source SDK contract.
| Code | When it occurs |
|---|---|
| empty | The encoded state is empty or not a string. |
| too_large | The encoded state exceeds 4096 bytes. |
| invalid_expected_version | expectedVersion is not an integer from 1 through 999. |
| malformed | The version prefix or field structure is malformed. |
| unsupported_version | The encoded version differs from expectedVersion. |
| too_many_fields | The encoded state contains more than 32 fields. |
| invalid_field | A field name is invalid or duplicated. |
| invalid_encoding | A field contains invalid or non-canonical percent encoding. |
SDK type flow
Produced by
Consumed by the SDK
What happens next
A checked snapshot or result annotation.
Failures and fixes
Malformed data, wrong versions, missing migration steps, excessive size, or non-string fields remain explicit failure branches. Do not silently replace corrupt security- or domain-sensitive values with defaults.
Availability
Public-source alpha API in 0.5.0-alpha; persistence support is host-dependent.
Exact declaration
export type DecodeFailure = { success: false, version: nil, fields: nil, error: DecodeError }