### 2.2.21 Completion_rest_engraver

This engraver replaces `Rest_engraver`. It plays some trickery to break long rests into the next measure.

Music types accepted:

rest-event

Properties (read)

> `completionUnit` (moment)

>   Sub-bar unit of completion.

> `measureLength` (moment)

>   Length of one measure in the current time signature.

> `measurePosition` (moment)

>   How much of the current measure have we had. This can be set manually to create incomplete measures.

> `middleCPosition` (number)

>   The place of the middle C, measured in half staff-spaces. Usually determined by looking at `middleCClefPosition` and `middleCOffset`.

Properties (write)

> `restCompletionBusy` (boolean)

>   Signal whether a completion-rest is active.

This engraver creates the following layout object(s):

Rest.

`Completion_rest_engraver` is not part of any context.

#### Internals Reference v2.18.2 (稳定分支).