comparisonsinto

Comparisonsinto is a term used in data processing and functional programming to describe a class of operations that apply multiple predicate checks to elements of a collection and collect the results into designated outputs or sinks. The core idea is to couple the evaluation of several comparisons with a configurable destination for the results, rather than performing a single filter or map pass.

In general, a comparisonsinto operation takes two main inputs: a collection of items and a set of predicates or test functions. For each item, every predicate is evaluated, and the outcome is gathered into a structured result. The destination can be a per-item result map, a per-predicate sink (a list or map of items that satisfy that predicate), or a combination of both. This design supports both item-centric views (what predicates does this item satisfy?) and sink-centric views (which items satisfy each predicate?).

Common patterns include item-centric results, where each item is annotated with a boolean vector indicating predicate satisfaction, and sink-centric routing, where items are appended to multiple output collections corresponding to the predicates they satisfy. Implementations can be eager or lazy and may support streaming or batched processing.

Example (item-centric): given items = [6, 7, 12] and predicates even(x) and large(x) with large(x) defined as x > 10, comparisonsinto returns a mapping like {6: {even: true, large: false}, 7: {even: false, large: false}, 12: {even: true, large: true}}.

Applications include data validation pipelines, feature extraction, and complex filtering where multiple criteria must be tracked simultaneously. See also: filter, map, partition, predicates, dataflow, and sinks.