Source file when_to_snapshot.ml

open! Core

type which_function =
  | Use_fzf_to_select_one
  | User_selected of string

type t =
  | Magic_trace_or_the_application_terminates
  | Application_calls_a_function of which_function

let param =
  let open Command.Param in
  flag
    "-trigger"
    (optional string)
    ~doc:
      "_ Selects when magic-trace takes a trace. There are three trigger modes to choose \
       from:\n\
       (1) If you do not provide [-trigger], magic-trace takes a snapshot when you \
       Ctrl+C it.\n\
       (2) If you provide [-trigger ?], magic-trace will open up a fuzzy-find dialog to \
       help you choose a symbol to trace. Fails if you don't have the \"fzf\" binary in \
       your PATH.\n\
       (3) If you provide [-trigger <FUNCTION NAME>], magic-trace will snapshot when the \
       application being traced calls the given function. This takes the fully-mangled \
       name, so if you're using anything except C, fuzzy-find mode will probably be \
       easier to use. [-trigger .] is a shorthand for [-trigger \
       magic_trace_stop_indicator].\n\
       (*) Regardless of trigger mode, magic-trace will always snapshot when the \
       application terminates if it has not yet triggered for any other reason."
  |> map ~f:(function
         | None -> Magic_trace_or_the_application_terminates
         | Some "?" -> Application_calls_a_function Use_fzf_to_select_one
         | Some "." ->
           Application_calls_a_function (User_selected Magic_trace.Private.stop_symbol)
         | Some symbol -> Application_calls_a_function (User_selected symbol))
;;