R/class_command.R

In targets: Dynamic Function-Oriented 'Make'-Like Declarative Pipelines

command_init <- function(
  expr = expression(NULL),
  packages = character(0),
  library = NULL,
  seed = 0L,
  deps = NULL,
  string = NULL
) {
  expr <- as.expression(expr)
  deps <- deps %|||% deps_function(embody_expr(expr))
  string <- string %|||% mask_pointers(tar_deparse_safe(expr))
  hash <- hash_object(string)
  command_new(expr, packages, library, deps, seed, string, hash)
}

command_new <- function(
  expr = NULL,
  packages = NULL,
  library = NULL,
  deps = NULL,
  seed = NULL,
  string = NULL,
  hash = NULL
) {
  force(expr)
  force(packages)
  force(library)
  force(deps)
  force(seed)
  force(string)
  force(hash)
  environment()
}

command_produce_build <- function(command, envir) {
  build_init(
    expr = command$expr,
    envir = envir,
    seed = command$seed,
    packages = command$packages,
    library = command$library
  )
}

command_clone <- function(command) {
  out <- command_new(
    command$expr,
    command$packages,
    command$library,
    command$deps,
    command$seed
  )
  out$string <- command$string
  out$hash <- command$hash
  out
}

command_validate <- function(command) {
  tar_assert_correct_fields(command, command_new)
  tar_assert_expr(command$expr)
  tar_assert_chr(command$packages)
  tar_assert_chr(command$library %|||% character(0))
  tar_assert_chr(command$deps)
  tar_assert_int(command$seed)
  tar_assert_scalar(command$seed)
  tar_assert_chr(command$string)
  tar_assert_scalar(command$string)
  tar_assert_chr(command$hash)
  tar_assert_scalar(command$hash)
}

command_null <- command_new(
  expr = expression(NULL),
  packages = character(0),
  deps = character(0),
  seed = 0L,
  string = "",
  hash = ""
)