package octez-libs
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doc/octez-libs.error-monad/Tezos_error_monad/TzCore/index.html
Module Tezos_error_monad.TzCore
Source
type error_category = [
| `Branch
(*Errors that may not happen in another context
*)| `Temporary
(*Errors that may not happen in a later context
*)| `Permanent
(*Errors that will happen no matter the context
*)
]
include Sig.CORE
with type error := error
and type error_category := error_category
The encoding for errors.
Note that this encoding has a few peculiarities, some of which may impact your code. These peculiarities are due to the type error
being an extensible variant.
Because the error
type is an extensible variant, you must register an encoding for each error constructor you add to error
. This is done via register_error_kind
.
Because the error
type is an extensible variant, with dynamically registered errors (see peculiarity above), there are no tags associated with each error. This does not affect the JSON encoding, but it does impose restrictions on the binary encoding. The chosen workaround is to encode errors as JSON and to encode the JSON to binary form. As a result, errors can be somewhat large in binary: they include field names and such.
Because the error
type is an extensible variant, with dynamically registered errors (see peculiarity above), the encoding must be recomputed when a new error is registered. This is achieved by the means of a Data_encoding.delayed
combinator: the encoding is recomputed on-demand. There is a caching mechanism so that, in the case where no new errors have been registered since the last use, the last result is used.
This last peculiarity imposes a limit on the use of error_encoding
itself. Specifically, it is invalid to use error_encoding
inside the ~json
argument of a Data_encoding.splitted
. This is because splitted
evaluates the delayed
combinator once-and-for-all to produce a json encoding. (Note that the following data-encoding combinators use splitted
internally: Data_encoding.Compact.make
, Data_encoding.assoc
, and Data_encoding.lazy_encoding
. As a result, it is invalid to use error_encoding
within the arguments of these combinators as well.)
val register_error_kind :
error_category ->
id:string ->
title:string ->
description:string ->
?pp:(Format.formatter -> 'err -> unit) ->
'err Data_encoding.t ->
(error -> 'err option) ->
('err -> error) ->
unit
The error data type is extensible. Each module can register specialized error serializers id
unique name of this error. Ex.: overflow_time_counter title
more readable name. Ex.: Overflow of time counter description
human readable description. Ex.: The time counter overflowed while computing delta increase pp
formatter used to pretty print additional arguments. Ex.: The time counter overflowed while computing delta increase. Previous value %d. Delta: %d encoder
decoder
data encoding for this error. If the error has no value, specify Data_encoding.empty
Classify an error using the registered kinds
Catch all error when 'deserializing' an error.
An error serializer
Error documentation
type error_info = {
category : error_category;
id : string;
title : string;
description : string;
schema : Data_encoding.json_schema;
}
Error information
find_info_of_error e
retrieves the `error_info` associated with the given error `e`.
Retrieves information of registered errors
include Sig.WITH_WRAPPED with type error := error
The purpose of this module is to wrap a specific error monad E
into a more general error monad Eg
.
val register_wrapped_error_kind :
(module Wrapped_error_monad) ->
id:string ->
title:string ->
description:string ->
unit
Same as register_error_kind
but for a wrapped error monad. The codec is defined in the module parameter. It makes the category of the error Wrapped
instead of Main
.