type when_ = [ | `Always| `Never| `Auto
]type when_ext = [ | `Extended| when_
]type answer = [ | `unsafe_yes| `all_yes| `all_no| `ask
]type yes_answer = [ | `unsafe_yes| `all_yes
]val bool_of_string : string -> bool optionval env : (string -> 'a) -> string -> 'a optionval env_bool : env_var -> bool optionval env_int : env_var -> int optionval env_string : env_var -> string optionval env_string_list : env_var -> string list optionval env_float : env_var -> float optionval resolve_when : auto:bool Stdlib.Lazy.t -> when_ -> boolmodule type Sig = sig ... end