Selectionswhere

Selectionswhere is a term used in some programming and data processing contexts to describe an operation that filters a collection by applying a predicate. The word combines the ideas of selecting elements from a set and constraining them with a where-like condition. In this sense, selectionswhere yields a subset consisting of those elements that satisfy the given condition.

The concept is often described as a higher-level abstraction for filtering tasks. It can appear in discussions of functional programming, data query languages, or data pipelines, where a sequence of transformations includes a dedicated selection step governed by a predicate. In practice, implementations vary: some treat selectionswhere as a pure function that returns a new collection, while others implement it as a lazy or streaming operation to avoid materializing large intermediate results.

Syntax and behavior are language-dependent. A typical form uses a collection and a predicate, such as selectionswhere(collection, predicate), or a method-style variant like collection.selectionswhere(predicate). The predicate is a function or expression evaluated for each element; elements for which the predicate is true are included in the result. Some implementations support multiple predicates, short-circuiting, or combinators to combine conditions.

Relation to other concepts is close to filter, select-if, or where clauses in SQL. Selectionswhere emphasizes the explicit pairing of a selection step with a conditional constraint, and it may be used as a design name in documentation or educational materials to distinguish the act of choosing items from the data source from subsequent transformations.

See also: filter, where-clause, select-if, data filtering, predicates.