Return Hook

[robcxyz]

Return Hook

None

• Proposal Status: implemented

• Issue Number: 256

• Proposal Doc: return-hook.md

Overview

NOTE: See return-key for an additional macro for ergonomics.

Currently when a declarative hook is called with an exec, the entire context is parsed with a special field for returning the appropriate value (return) being used to specify what the result is of that parsing.

This proposal would add a hook for being able to escape parsing and return a specific value as the public context.

Examples

Normal parsing

foo: bar

return a key->: return {{foo}}

Would result in the value bar being returned in the public context.

Similarly with exec:

<-:

  exec:

    foo: bar

    return a key->: return {{foo}}

    something that: is ignored

Implementation

Context can be set within the hook. Need a way to send kill signal to parsing though since once the context is set, we need to be able to stop the parsing of the next key.

NOTE: Likely this kill signal approach would also enable a macro like approach for implementing return-key.