An Ecoproto_error e is a shell error that carry a protocol error.

Each protocol has its own error-monad (instantiated when this module here is applied) with a fresh extensible error type. This protocol-specific error type is incompatible with the shell's. The Ecoproto_error constructor belongs to the shell's error type and it carries the errors of the protocol's specific error type back into the shell's.

The function wrap_tz* below provide wrappers for three different levels: errors, traces, and tzresults. They are used within the implementation of the environment to translate some return values from the protocol's error monad into the shell's. They are exported because they can be useful for writing tests for the protocol (i.e., for the tests located in src/proto_*/lib_protocol/test/) and for writing protocol-specific support libraries and binaries (i.e., for the code in src/proto_*/lib_{client,delegate,etc.}).

wrap_tzerror e is a shell error wrapping the protocol error e. (It is Ecoproto_error e.)

wrap_tztrace t is a shell trace composed of the wrapped errors of the protocol trace t.

wrap_tzresult r is a shell tzresult that carries the same result as or a wrapped trace of the protocol tzresult r. (It is Ok x if r is Ok x, it is Error (wrap_tztrace t) if r is Error t.)