$ show olekukonko/tablewriter
This is a Go library for rendering richly formatted tables in a variety of output formats, including ASCII, Unicode, Markdown, HTML, ANSI-colored, and SVG. It provides both a batch mode (`Render`) and a streaming mode (`Start`, `Append`, `Close`) for incremental table generation. The library supports advanced features such as horizontal, vertical, and hierarchical cell merging, per-column alignment, padding, word wrapping, and custom cell formatters. It includes a CLI tool `csv2table` that converts CSV input to tables with the full feature set. The codebase is modular, with separate packages for display width calculation (East Asian language support), word wrapping (minimal raggedness algorithm), an LRU cache, and a set of pluggable renderers. Configuration is done via functional options and a fluent `ConfigBuilder` pattern. Although comprehensive, the API is in a state of transition: many legacy methods (e.g., `SetBorder`, `SetAutoFormatHeaders`) are deprecated, and the migration guide warns that the current version (v1) is still evolving. The architecture is sound, with clear separations between data processing (`tablewriter` core), presentation (`tw` types and `renderer` implementations), and utility packages (`twwidth`, `twwarp`, `twcache`). The library is well-tested with over 50 test files and benchmarks, and demonstrates strong engineering practices.
The LLM identified 5 files worth highlighting for reuse:
Provides accurate display width calculation for strings, including East Asian wide characters (e.g., CJK) and emojis. Uses a singleton cache to store results and supports multiple strategies for determining environment width (terminal, locale, modern terminal heuristics). This is a self-contained utility that can be extracted and reused in any Go project that needs to compute visual character widths, such as terminal UI libraries or column alignment tools.
A generic, thread-safe LRU cache implementation with configurable capacity. Supports `Get`, `Set`, `Remove`, `Clear`, and iteration via `Range` method. The cache is used internally for memoizing stringer reflection results but is fully generic and can be extracted for any key-value caching need. It includes benchmarks and concurrent tests, demonstrating robust engineering.
Defines the `Symbols` interface and provides a rich set of predefined border styles: ASCII, Light, Heavy, Double, Rounded, Markdown, Graphical, Emoji-based, and more. Each style is a concrete struct (e.g., `SymbolsLight`) that implements the interface. This pattern allows renderers to use any symbol set without modification. The package is self-contained and can be reused as a drop-in symbol library for any text-based table or grid rendering system.
The default renderer implementation that produces ASCII/Unicode tables with full support for borders, alignment, padding, and cell merging. It implements the `tw.Renderer` interface, making it replaceable by custom renderers. The file demonstrates clean separation of rendering logic from table data processing, and its design can be adapted to create custom output formats (e.g., for JSON or CSV).
Implements a fluent `ConfigBuilder` that allows chaining method calls to build a complete `Config` structure for table rendering. It provides builders for headers, rows, footers, columns (by index), and behavioral settings (merging, width, alignment). This pattern encapsulates complex configuration in a readable, discoverable way and is decoupled from the table rendering logic. It can be extracted as a general-purpose configuration pattern for other libraries.