$ show google/go-cmp
go-cmp is a Go library for comparing values semantically, designed as a safer and more powerful alternative to reflect.DeepEqual. It provides the `cmp.Equal` and `cmp.Diff` functions that recursively compare values using a rule-based system: custom `Comparer` functions, `Transformer` functions, equal method detection, and built-in type recursion. Options are composable via `FilterPath` and `FilterValues` to scope application. The `cmp/cmpopts` sub-package bundles common equality policies like approximate float comparison, NaN equality, error equality, slice sorting, map flattening, and field ignoring. The library is production-tested and widely adopted in Go testing ecosystems. Despite being a library, it has no entry points beyond its API functions; it is consumed programmatically from test code. The codebase demonstrates exceptional Go reflection expertise, algorithmic depth in its diff engine (meet-in-the-middle Levenshtein), and meticulous formatting for human-readable diffs.
The LLM identified 1 files worth highlighting for reuse:
Implements a fast, sub-optimal Levenshtein distance algorithm to compute edit scripts for two lists. Uses a greedy meet-in-the-middle approach with forward and reverse searches, zigzag path exploration, and a search budget. The algorithm is deliberately non-optimal for performance but produces decent results. It is self-contained, depends only on standard library and an internal deterministic flag, and can be extracted for use in any Go project needing approximate list differencing. Also includes a debug mode (build tag cmp_debug) that visualizes the algorithm in real-time.