Singly-linked list/Element definition: Difference between revisions
Singly-linked list/Element definition (view source)
Revision as of 08:10, 12 September 2021
, 2 years ago→{{header|jq}}
Line 754:
var head = createLinkedListFromArray([10,20,30,40]);</lang>
=={{header|jq}}==
{{works with|jq}}
'''Works with gojq, the Go implementation of jq'''
In this entry, we envision a canonical mapping of SLLs to JSON objects as follows:
* the empty SLL is represented by `{"next": null}`
* a non-empty SLL is represented by an object of the form:
{"item": $item, "next": $next}
where $next is the canonical representative of a SLL, and $item may be any JSON value.
Examples:
* The empty SLL: { "next": null}
* A SLL holding the value 1 and no other: {"item": 1, "next": null}
<br>
Since it may be useful to allow non-canonical representatives of
SLLs, the following predicates adhere to the following principles:
* the empty SLL can be represented by any JSON object which does NOT have
a key named "item" and for which .next is `null`;
* non-empty SLLs can be represented by JSON objects having an "item" key and
for which .next is either `null` or a representative of a SLL.
Note that according to these principles, the JSON value `null` does
not represent a SLL, and JSON representatives of SLLs may have additional keys.
<lang jq>def is_empty_singly_linked_list:
type == "object" and .next == null and (has("item")|not);
def is_singly_linked_list:
is_empty_singly_linked_list or
(type == "object"
and has("item")
and (.next | ((. == null) or is_singly_linked_list)));
# Test for equality without checking for validity:
def equal_singly_linked_lists($x; $y):
($x|is_empty_singly_linked_list) as $xempty
| if $xempty then ($y|is_empty_singly_linked_list)
elif ($y|is_empty_singly_linked_list)
then $xempty
else ($x.item) == ($y.item)
and equal_singly_linked_lists($x.next; $y.next)
end;</lang>
=={{header|Julia}}==
| |||