## 9.1 Chunks in General

The module `Chunk` contains procedures operating on chunks.

`.`

  > `{Value.'.'` `+RC``` `+LI``` `X``}`

  returns the field `X` of `RC` at feature `LI`.

`HasFeature`

  > `{Value.hasFeature` `+RC``` `+LI``` `?B``}`

  tests whether `RC` has feature `LI`.

`CondSelect`

  > `{Value.condSelect` `+RC``` `+LI``` `X``` `Y``}`

  returns the field `Y` of `RC` at `LI`, if `RC` has feature `LI`. Otherwise, returns `X`.

`IsChunk`

  > `{Chunk.is` `+X``` `?B``}`

  tests whether `X` is a chunk.

`NewChunk`

  > `{Chunk.new` `+R``` `?C``}`

  returns a new chunk with the same features and fields as `R`.