language.md
In transltr: Support Many Languages in R

language_set() validates lang

Code
  language_set(1L)
Condition
  Error:
  ! 'lang' must be a non-NA and non-empty character of length 1.

language_set() throws an error if it fails to set env variable

Code
  # .__LGL_DEBUG_FLAG was set equal to TRUE to generate this error.
  language_set("test-en")
Condition
  Error:
  ! failed to set language 'test-en'.

language_set() throws an error if it fails to unset env variable

Code
  # .__LGL_DEBUG_FLAG was set equal to TRUE to generate this error.
  # Therefore, the language is empty in the error message because it
  # was reset before the flag triggers.
  language_set(NULL)
Condition
  Error:
  ! failed to unset current language ''.

language_source_set() validates lang

Code
  language_source_set(1L)
Condition
  Error:
  ! 'lang' must be a non-NA and non-empty character of length 1.

language_source_set() throws an error if it fails to set env variable

Code
  # .__LGL_DEBUG_FLAG was set equal to TRUE to generate this error.
  language_source_set("test-en")
Condition
  Error:
  ! failed to set source language 'test-en'.

language_source_set() throws an error if it fails to unset env variable

Code
  # .__LGL_DEBUG_FLAG was set equal to TRUE to generate this error.
  # Therefore, the language is 'en' (the default) in the error message
  # because it was reset before the flag triggers.
  language_source_set(NULL)
Condition
  Error:
  ! failed to unset current source language 'en'.