.. include:: ../global.rst

.. idio:currentmodule:: expect

expect Values
-------------


.. _`expect/spawn-id`:

.. idio:value:: spawn-id

   :canonical: expect/spawn-id
   :scope: dynamic

   :type: :ref:`expect/struct-spawn <expect/struct-spawn>`
   
   ``spawn-id`` is set by and returned from :ref:`expect/spawn
   <expect/spawn>`.
   
   .. tip::
   
      ``spawn-id`` defaults to ``#f`` however if you set it to ``#n`` or
      a list of spawn-id(s) then ``spawn`` will prepend any new value to
      the list.
   
      If you want to revert this behaviour, set ``spawn-id`` back to a
      single ``struct-spawn`` value or to ``#f``.
   
      You must manage ``spawn-id`` under these circumstances.  For
      example, :ref:`exp-wait <expect/exp-wait>` does not modify a
      list-variant ``spawn-id`` and it will continue as a list of
      (expired) spawned processes.
   

.. _`expect/user-spawn-id`:

.. idio:value:: user-spawn-id

   :canonical: expect/user-spawn-id
   :scope: dynamic

   :type: :ref:`expect/struct-spawn <expect/struct-spawn>`
   
   ``user-spawn-id`` is a spawn-id representing the user, more
   particularly ``libc/STDIN_FILENO``.
   
   .. warning::
   
      Calling :ref:`exp-close <expect/exp-close>` or :ref:`exp-wait
      <expect/exp-wait>` with ``user-spawn-id`` may have undesired
      consequences.
   

.. _`expect/tty-spawn-id`:

.. idio:value:: tty-spawn-id

   :canonical: expect/tty-spawn-id
   :scope: dynamic

   :type: :ref:`expect/struct-spawn <expect/struct-spawn>`
   
   ``tty-spawn-id`` is a spawn-id representing :file:`/dev/tty`.
   
   If :file:`/dev/tty` is not available, ``tty-spawn-id`` is ``#f``.
   
   .. warning::
   
      Calling :ref:`exp-close <expect/exp-close>` or :ref:`exp-wait
      <expect/exp-wait>` with ``tty-spawn-id`` may have undesired
      consequences.
   

.. _`expect/exp-timeout`:

.. idio:value:: exp-timeout

   :type: fixnum
   :canonical: expect/exp-timeout
   :scope: dynamic

   :default: ``-1``
   
   ``exp-timeout`` is the timeout used by :ref:`exp-case
   <expect/exp-case>` measured in seconds.
   
   A value of 0 represents a poll of the device.
   
   A value of -1, the default, represents an infinite timeout.
   
   .. note::
   
      :manpage:`expect(1)` defaults to a timeout of 10 (seconds).  Don
      Libes has indicated some regret over this value and that
      it should be off by default (see `Writing a Tcl
      Extention in only... 7 Years` in the Proceedings of the Fifth
      Annual Tcl/Tk Workshop Boston, Massachusetts, July 1997).
   

.. _`expect/exp-match-max`:

.. idio:value:: exp-match-max

   :type: fixnum
   :canonical: expect/exp-match-max
   :scope: dynamic

   :default: ``2000``
   
   ``exp-match-max`` is the number of code points to retain in the buffer
   between rounds.
   
   

.. _`expect/exp-slow`:

.. idio:value:: exp-slow

   :type: pair
   :canonical: expect/exp-slow
   :scope: dynamic

   :default: ``(600 50)`` -- 600 code points and a 50ms delay
   
   ``exp-slow`` is a tuple of the number of code points in a burst
   prefixed by a delay of a number of milliseconds.  The default is
   roughly equivalent to a 115200 baud modem (if the code points were
   ASCII).
   

.. _`expect/exp-human`:

.. idio:value:: exp-human

   :type: pair
   :canonical: expect/exp-human
   :scope: dynamic

   :default: ``(180 240 1 45 360)``
   
   ``exp-human`` is a tuple of:
   
   * the average gap between in-word code points
   
   * the average gap transitioning from an in-word code point to a
     non-word code point
   
   * a moderating factor, K:
   
     "tiredness" might be represented by a K < 1 and preternaturally
     consistent typing by a K > 1
   
   * the minimum inter-code point gap, defaulting to a quarter of the
     in-word gap
   
   * the maximum inter-code point gap, defaulting to twice the in-word
     gap
   
   The default is roughly equivalent to a 60 wpm typist.
   
   The algorithm used to calculate the inter-code point gap is the
   inverse cumulative distribution function of the Weibull distribution.
   The same as Don Libes' :manpage:`expect(1)`.
   



.. include:: ../commit.rst