ListTSort

ListTSort is a generic sorting utility designed for lists of elements, where the element type is captured by a type parameter T. It provides a type-safe interface for sorting using either a user-provided comparator or the natural ordering of the elements. The design emphasizes stability, interoperability with common list interfaces, and predictable performance across typical workloads.

The core of ListTSort offers multiple sorting strategies that can be selected automatically or configured by the user. It includes a stable mergesort variant suitable for preserving the relative order of equal elements, as well as an in-place quicksort-based variant aimed at reduced memory usage. In addition, the library exposes a key-based sorting option that sorts by a derived key function while preserving the element’s type information, enabling flexible sorting criteria without sacrificing type safety.

Complexity and behavior depend on the chosen strategy. The stable configurations typically provide O(n log n) time in average and worst cases for comparison-based sorts, with O(n) additional space for mergesort and less for in-place variants. The API supports customization for null handling, error reporting, and tie-breaking through the comparator or key function. ListTSort is designed to integrate with common collection interfaces and to preserve the element type across sorting operations, aiding static type checking in downstream code.

Usage commonly involves supplying a list of T and either a comparator function or a key extractor, with optional secondary criteria. Examples include sorting by natural order, sorting by a specific field, or sorting by a computed key, all while maintaining type safety and predictable behavior across languages that implement the library.