dream2nix/docs/translators.md

Translators

This document classifies different methods for translating requirement/lock files to the generic lock format and describes how the resulting packages can be integrated into nix builds inside and outside of nixpkgs.

pure-nix (preferred)

Suitable if:

• the input contains information like URLs and hashes
• nix supports the hashing algorithm
• the input can be processed with the nix language directly

Usage outside of nixpkgs:

• The input + translator are enough, not requiring any pre-processing.

Usage inside nixpkgs:

• The input + translator are enough, not requiring any pre-processing.

IFD/recursive (compatible with import from derivation or recursive nix)

Suitable if:

• the input contains information like URLs and hashes
• nix understands the hashing algorithm
• to process the input, a nix build is required, because for example:
  • the format cannot be parsed with the nix language (yaml etc.)
  • processing the input is too complex and therefore inefficient in nix language

Usage outside of nixpkgs:

• The input + translator are enough. The generic lock file is generated via IFD

Usage inside nixpkgs:

• generic lock file must be pre-generated using dream2nix cli

impure (running outside of nix build)

Suitable if:

• the input is missing URLs or hashes
• the method used to process the input contains impurities, like for example:
  • queries to an online index with varying responses
  • packages must be downloaded to discover important meta data like dependencies.

Usage outside of nixpkgs:

• generic lock file must be pre-generated using dream2nix cli

Usage inside nixpkgs:

• generic lock file must be pre-generated using dream2nix cli