insertionsfrom

Insertionsfrom is a descriptive term used in computing to denote an operation that inserts elements from a source sequence into a target sequence starting at a given position. It is not a formal built-in operator in mainstream languages; rather, it appears as a function name or conceptual description in libraries, pseudocode, and documentation to express the idea of merging two sequences by splicing in the contents of the source.

Definition and variants: The operation typically takes at least two sequences and an index. Depending on the design, it may return a new sequence with the insertion, or modify the target in place. It may insert all elements of the source, or only a prefix or subset. Behavior at the end of the target and handling of empty inputs are common design considerations. Some implementations prefer immutable semantics (producing a new sequence) while others favor in-place modification for efficiency.

Examples: target = [1, 2, 3, 6, 7], source = [4, 5], index = 3 yields [1, 2, 3, 4, 5, 6, 7] in a non-mutating variant. In an in-place variant, the target sequence would be updated directly. Some libraries support additional options such as inserting at multiple positions, avoiding duplicates, or inserting with a given step or stride.

Relation to other concepts: Insertionsfrom is related to splice, merge, concatenation, and patch operations. Notation and naming vary between languages and libraries, so it is often implemented as a custom function or method, rather than a universal operator.

See also: splice, merge, concatenation, patch, insert.