Filter / forgiving modifiers

[pokey]

• [x] Error when can't expand ("funk") (default behaviour)
• [ ] Keep only inputs which don't error when applying modifier, but return the input unchanged ("can funk")
  • eg is it weakly contained by visible characters? ("can char")
• [ ] Drop target when can't expand; expand those that can ("only funk")
• [ ] Passthrough unmodified those that can't expand; expand those that can ("soft funk")

Implementation

We can implement this with a new compositional modifier:

interface ErrorSuppressorModifier {
   type: "errorSuppressor";
   modifier: Modifier;
   onSuccess: "useOriginal" | "useModified";
   onError: "useOriginal" | "drop";
}

The modifier stage would just apply modifier, surrounded by a try block. On success it would either use the original or modified depending on onSuccess. On error it would either use original or return [] depending on onError

Then Talon-side we could map spoken forms as follows:

{
    "can": {"onSuccess": "useOriginal", "onError": "drop"},
    "only": {"onSuccess": "useModified", "onError": "drop"},
    "soft": {"onSuccess": "useModified", "onError": "useOriginal"},
}

Note that these spoken forms can't be used on their own; they are of the form {user.cursorlessErrorSuppressor} <user.cursorlessModifier>, and construct a composed modifier

See also #1006