TIP #283 Version 1.1: Modify Ensemble -unknown Behaviour

This is not necessarily the current version of this TIP.

Abstract

This TIP proposes that an ensemble's unknown handler resolve the rewritten command in the ensemble's namespace.

Rationale

Ensembles as proposed in TIP #112 have an unknown handler behaviour that makes it impossible to combine it with the [namespace path] and [namespace unknown] features of the ensemble's namespace.

This is because the command returned from the unknown handler is invoked in the ensemble's caller namespace: the only way to insure that it is called in the ensemble's namespace is by returning a FQ command name. But FQ command names bypass the [namespace path] and [namespace unknown] mechanisms.

Proposed Change

This TIP proposes to fix this by changing the man page description of the ensemble unknown handler from:

It is up to the unknown handler to supply all namespace qualifiers if the implementing subcommand is not in the namespace of the caller of the ensemble command.

to:

The implementing subcommand is looked up in the ensemble's namespace using normal command location rules.

Reference Implementation and Documentation

[RFE 1577282] (which depends on [Patch 1577278]) provides an implementation, with tests and docs.

Copyright

This document has been placed in the public domain.

This is not necessarily the current version of this TIP.