rd-helpdb

rd-helpdb reads the compiled help database of an installed R package and provides alias, topic, help-search, vignette, and demo access.

Overview

An installed package help database consists of help/aliases.rds, the help/<pkg>.rdx index and help/<pkg>.rdb record pair, Meta/hsearch.rds, and optional Meta/vignette.rds and Meta/demo.rds indexes. rd-helpdb reads the standalone RDS files, exposes validated typed vignette and demo entries, and reads the compressed records addressed by the .rdx index; it does not discover package directories through R's .libPaths().

Standalone .rds envelope handling is delegated to rd-rds. Consumers that need a canonical document model can lower decoded help objects into rd-ast.

Features

The gzip, xz, bzip2, and zstd features are enabled by default. They control only the compression envelopes accepted for standalone .rds files such as aliases.rds, <pkg>.rdx, and the Meta/*.rds indexes. For example, a consumer that only needs gzip-enveloped .rds files can use:

[dependencies]
rd-helpdb = { version = "0.3.1", default-features = false, features = ["gzip"] }

The gzip feature is unrelated to the zlib record stream inside <pkg>.rdb. .rdb record decompression is mandatory for this format and is always compiled in, so --no-default-features does not remove the flate2 dependency.

Stability

Alias, topic, search, vignette, and demo reading for an explicitly named installed-package directory is supported. Discovering R libraries or packages on a machine is out of scope; see the workspace stability policy.

License

MIT; see the workspace license. See the workspace README for repository status and layout.