Skip to contents

Generic Nix expression builder for R, Python, and Julia data readers

Source: R/rxp_io.R
rxp_file.Rd

You should not call it directly, but instead use one of rxp_r_file(), rxp_py_file() or rxp_jl_file().

Usage

rxp_file(
  lang,
  name,
  path,
  read_function,
  user_functions = "",
  nix_env = "default.nix",
  env_var = NULL,
  encoder = NULL
)

Arguments

lang

"R", "Py" or "Jl".

name

Symbol, the name of the derivation.

path

Character, the file path to include (e.g., "data/mtcars.shp") or a folder path (e.g., "data"). See details.

read_function

Function, an R function to read the data, taking one argument (the path). This can be a user-defined function that is made available using user_functions. See details.

user_functions

Character vector, user-defined functions to include. This should be a script (or scripts) containing user-defined functions to include during the build process for this derivation. It is recommended to use one script per function, and only include the required script(s) in the derivation.

nix_env

Character, path to the Nix environment file, default is "default.nix".

env_var

List, defaults to NULL. A named list of environment variables to set before running the R script, e.g., c(VAR = "hello"). Each entry will be added as an export statement in the build phase.

encoder

Function/character, defaults to NULL. A language-specific serializer to write the loaded object to disk.

  • R: function/symbol/character (e.g., qs::qsave) taking (object, path). Defaults to saveRDS.

  • Python: character name of a function taking (object, path). Defaults to using pickle.dump.

  • Julia: character name of a function taking (object, path). Defaults to using Serialization.serialize.

Value

An object of class rxp_derivation.

Details

Creates a Nix derivation that reads a file or folder of data using R, Python, or Julia. Handles user-defined functions, environment variables, and Nix environment specification.