
set_prompt(+InStream, +Prompt, +OutStream)

   The prompt Prompt is output on the stream OutStream for input to the input
stream InStream.



Arguments
   InStream            Integer (stream number) or Atom (reserved or user-defined                symbolic stream name).
   Prompt              String or atom.
   OutStream           Integer (stream number) or Atom (reserved or user-defined                symbolic stream name).

Type
   Obsolete

Description
   The prompt Prompt is output on the stream OutStream for input to the
   input stream InStream.


   When new data is to be read from an input stream, the system prints on
   the specified output stream a prompt, to notify the user for input.


   InStream and OutStream can be symbolic stream names (atom) or physical
   stream numbers (integer).


   InStream must be an existing stream open in read or update mode.
   OutStream must be an existing stream open in write or update mode.


   Note that the prompt for toplevel-input printed by the system at the end
   of each query is made using the predicate toplevel-prompt/1 and not by
   using the string set by set_prompt/3.




Modes and Determinism
   set_prompt(+, +, +) is det

Exceptions
     4 --- One or more of InStream, Prompt or OutStream are not    instantiated.
     5 --- Either InStream or OutStream (or both) is neither an atom    nor an integer.
     5 --- Prompt is neither an atom nor a string.
   192 --- InStream is in write mode.
   192 --- OutStream is in read mode.

Examples
   
Success:
  [eclipse]: get_prompt(input,_,Out),
  > set_prompt(input,"myprompt> ",Out).
  Out = 1
  yes.
  [eclipse]: get_prompt(input,Prompt,_),
  myprompt> !.
  Prompt = "myprompt> "
  yes.

  [eclipse]: read( input,X).
  > a.
  X = a
  yes.
  [eclipse]: set_prompt(input, "Enter a term: ", output).
  yes.
  [eclipse]: read(input,X).
  Enter a term: a.
  X = a
  yes.

  [eclipse]: get_stream(debug_input,S),
  > set_prompt(S, "   DEBUG: ", 1).
  S = 3
  yes.
  [eclipse]: trace.
  yes.
  [eclipse]: length([a,b],N).
  S (1) 0  CALL   length([a, b], _g52)   DEBUG: creep
  S (1) 0  EXIT   length([a, b], 2)   DEBUG: creep
  N = 2
  yes.


Error:
  set_prompt(4, Prompt, 1).        (Error 4).
  set_prompt(4, 4, 1).             (Error 5).
  set_prompt(output, "p> ", Stream). (Error 192).





See Also
   set_stream_property / 3, get_prompt / 3
