object

# `zlist`

Zipper list predicates. Zippers should be regarded as opaque terms.

Author: Paulo Moura
Version: 1.01
Date: 2019/3/12
Compilation flags:
`static, context_switching_calls`
Implements:
`public` zipperp
Remarks:
(none)
Inherited public predicates:
apply/2 current/2 delete_all_after/2 delete_all_after_and_unzip/2 delete_all_before/2 delete_all_before_and_unzip/2 delete_and_next/2 delete_and_previous/2 delete_and_unzip/2 forward/2 forward/3 insert_after/3 insert_before/3 next/2 next/3 previous/2 previous/3 replace/3 rewind/2 rewind/3 unzip/2 zip/2 zip/3

- Public predicates

  - `zip_at_index/4`

- Protected predicates

- Private predicates

- Operators

## Public predicates

### `zip_at_index/4`

Adds a zipper to a list opened at the given index and also returns the element at the index. Fails if the list is empty or the index (starting at 1) does not exist.

Compilation flags:
`static`
Template:
`zip_at_index(Index,List,Zipper,Element)`
Mode and number of proofs:
`zip_at_index(+natural,+list,--zipper,--term)` - `zero_or_one`

## Protected predicates

(no local declarations; see entity ancestors if any)

## Private predicates

(no local declarations; see entity ancestors if any)

## Operators

(none)