map_negative_index

Maps a negative index to its positive equivalent based on the provided length, or returns the index unchanged if it is already non-negative.

def map_negative_index(
    index: integer,
    length: integer
) - > integer

Converts a potentially negative sequence index into its equivalent positive absolute position. This is used to support Python-style negative indexing where -1 represents the last element in a collection of a specific length.

Parameters

Name	Type	Description
index	integer	The sequence index to be normalized, which may be negative.
length	integer	The total number of elements in the sequence used to calculate the positive offset.

Returns

Type	Description
integer	The normalized non-negative index if the input was negative, or the original index if it was already positive.