$ show schollz/progressbar
This is a well-crafted Go library providing a thread-safe, highly customizable progress bar for terminal applications. It supports both determinate (known maximum) and indeterminate (spinner) modes, with features like elapsed time, predicted time remaining, byte throughput, iterations per second, and configurable themes (including ASCII, Unicode, and custom). The library is designed for ease of use with convenient constructors (Default, DefaultBytes) and a fully functional options pattern for deep customization. It is used as an io.Writer in download scenarios and includes a built-in HTTP server for external monitoring of progress state. The codebase is clean, well-tested, and follows Go best practices.
The LLM identified 2 files worth highlighting for reuse:
The entire ProgressBar struct and its functional Options pattern. This is a textbook implementation of the functional options pattern in Go, allowing for clean and extensible configuration. The config struct centralizes all tunable parameters, and each Option is a self-contained function that modifies it. This pattern is highly reusable in any Go project that needs complex configuration without breaking API compatibility.
The OptionSetRateAveragingWindow function and the associated trimRateSamples logic. This feature allows users to smooth out rate and ETA estimates for long-running tasks by averaging over a trailing time window rather than a fixed number of samples. The implementation correctly handles edge cases (e.g., tiny windows, legacy fallback) and is a non-trivial addition that demonstrates advanced engineering thinking.