DOC: Define ipy directive as such in docs.

By utilizing the directive `rst:directive::`, one can now link to the
documentation on the sphinx directive using an inline reference as well
as now being able to link to any of the options.

Put this early in the documentation as it's useful to quickly summarize
the options and decorators available to the user immediately.

The currently provided examples are phenomenal but having a thorough
reference and all of the options in one place and having them be easy to
create a hyperlink to is also very important.

docs/source/sphinxext.rst

@@ -1,473 +1,520 b''
 
 .. _ipython_directive:
 
 ========================
 IPython Sphinx Directive
 ========================
 
 .. note::
 
    The IPython Sphinx Directive is in 'beta' and currently under
    active development. Improvements to the code or documentation are welcome!
 
-The ipython directive is a stateful ipython shell for embedding in
-sphinx documents.  It knows about standard ipython prompts, and
-extracts the input and output lines.  These prompts will be renumbered
-starting at ``1``.  The inputs will be fed to an embedded ipython
-interpreter and the outputs from that interpreter will be inserted as
-well.  For example, code blocks like the following::
+.. |rst| replace:: reStructured text
+
+The :rst:dir:`ipython` directive is a stateful shell that can be used
+in |rst| files.
+
+It knows about standard ipython prompts, and extracts the input and output
+lines.  These prompts will be renumbered starting at ``1``.  The inputs will be
+fed to an embedded ipython interpreter and the outputs from that interpreter
+will be inserted as well.  For example, code blocks like the following::
 
   .. ipython::
 
      In [136]: x = 2
 
      In [137]: x**3
      Out[137]: 8
 
 will be rendered as
 
 .. ipython::
 
    In [136]: x = 2
 
    In [137]: x**3
    Out[137]: 8
 
 .. note::
 
    This tutorial should be read side-by-side with the Sphinx source
    for this document because otherwise you will see only the rendered
    output and not the code that generated it.  Excepting the example
    above, we will not in general be showing the literal ReST in this
    document that generates the rendered output.
 
 
+Directive and options
+=====================
+
+The IPython directive takes a number of options detailed here.
+
+.. rst:directive:: ipython
+
+   Create an IPython directive.
+
+   .. rst:directive:option:: doctest
+
+      Run a doctest on IPython code blocks in rst.
+
+   .. rst:directive:option:: python
+
+      Used to indicate that the relevant code block does not have IPython prompts.
+
+   .. rst:directive:option:: okexcept
+
+      Allow the code block to raise an exception.
+
+   .. rst:directive:option:: okwarning
+
+      Allow the code block to emit an warning.
+
+   .. rst:directive:option:: suppress
+
+      Silence any warnings or expected errors.
+
+   .. rst:directive:option:: verbatim
+
+      A noop that allows for any text to be syntax highlighted as valid IPython code.
+
+   .. rst:directive:option:: savefig: OUTFILE [IMAGE_OPTIONS]
+
+      Save output from matplotlib to *outfile*.
+
+It's important to note that all of these options can be used for the entire
+directive block or they can decorate individual lines of code as explained
+in :ref:`pseudo-decorators`.
+
+
 Persisting the Python session across IPython directive blocks
 =============================================================
 
 The state from previous sessions is stored, and standard error is
 trapped. At doc build time, ipython's output and std err will be
 inserted, and prompts will be renumbered. So the prompt below should
 be renumbered in the rendered docs, and pick up where the block above
 left off.
 
 .. ipython::
   :verbatim:
 
   In [138]: z = x*3   # x is recalled from previous block
 
   In [139]: z
   Out[139]: 6
 
   In [142]: print(z)
   6
 
   In [141]: q = z[)   # this is a syntax error -- we trap ipy exceptions
   ------------------------------------------------------------
      File "<ipython console>", line 1
        q = z[)   # this is a syntax error -- we trap ipy exceptions
 	     ^
   SyntaxError: invalid syntax
 
 
 Adding documentation tests to your IPython directive
 ====================================================
 
 The embedded interpreter supports some limited markup.  For example,
 you can put comments in your ipython sessions, which are reported
 verbatim.  There are some handy "pseudo-decorators" that let you
 doctest the output.  The inputs are fed to an embedded ipython
 session and the outputs from the ipython session are inserted into
 your doc.  If the output in your doc and in the ipython session don't
 match on a doctest assertion, an error will occur.
 
 
 .. ipython::
 
    In [1]: x = 'hello world'
 
    # this will raise an error if the ipython output is different
    @doctest
    In [2]: x.upper()
    Out[2]: 'HELLO WORLD'
 
    # some readline features cannot be supported, so we allow
    # "verbatim" blocks, which are dumped in verbatim except prompts
    # are continuously numbered
    @verbatim
    In [3]: x.st<TAB>
    x.startswith  x.strip
 
 For more information on @doctest decorator, please refer to the end of this page in Pseudo-Decorators section.
 
 Multi-line input
 ================
 
 Multi-line input is supported.
 
 .. ipython::
    :verbatim:
 
    In [130]: url = 'http://ichart.finance.yahoo.com/table.csv?s=CROX\
       .....: &d=9&e=22&f=2009&g=d&a=1&br=8&c=2006&ignore=.csv'
 
    In [131]: print(url.split('&'))
    ['http://ichart.finance.yahoo.com/table.csv?s=CROX', 'd=9', 'e=22',
 
 Testing directive outputs
 =========================
 
 The IPython Sphinx Directive makes it possible to test the outputs that you provide with your code. To do this,
 decorate the contents in your directive block with one of the following:
 
   * list directives here
 
 If an IPython doctest decorator is found, it will take these steps when your documentation is built:
 
 1. Run the *input* lines in your IPython directive block against the current Python kernel (remember that the session
 persists across IPython directive blocks);
 
 2. Compare the *output* of this with the output text that you've put in the IPython directive block (what comes
 after `Out[NN]`);
 
 3. If there is a difference, the directive will raise an error and your documentation build will fail.
 
 You can do doctesting on multi-line output as well.  Just be careful
 when using non-deterministic inputs like random numbers in the ipython
 directive, because your inputs are run through a live interpreter, so
 if you are doctesting random output you will get an error.  Here we
 "seed" the random number generator for deterministic output, and we
 suppress the seed line so it doesn't show up in the rendered output
 
 .. ipython::
 
    In [133]: import numpy.random
 
    @suppress
    In [134]: numpy.random.seed(2358)
 
    @doctest
    In [135]: numpy.random.rand(10,2)
    Out[135]:
    array([[0.64524308, 0.59943846],
           [0.47102322, 0.8715456 ],
           [0.29370834, 0.74776844],
           [0.99539577, 0.1313423 ],
           [0.16250302, 0.21103583],
           [0.81626524, 0.1312433 ],
           [0.67338089, 0.72302393],
           [0.7566368 , 0.07033696],
           [0.22591016, 0.77731835],
           [0.0072729 , 0.34273127]])
 
 For more information on @supress and @doctest decorators, please refer to the end of this file in
 Pseudo-Decorators section.
 
 Another demonstration of multi-line input and output
 
 .. ipython::
    :verbatim:
 
    In [106]: print(x)
    jdh
 
    In [109]: for i in range(10):
       .....:     print(i)
       .....:
       .....:
    0
    1
    2
    3
    4
    5
    6
    7
    8
    9
 
 
 Most of the "pseudo-decorators" can be used an options to ipython
 mode.  For example, to setup matplotlib pylab but suppress the output,
 you can do.  When using the matplotlib ``use`` directive, it should
 occur before any import of pylab.  This will not show up in the
 rendered docs, but the commands will be executed in the embedded
 interpreter and subsequent line numbers will be incremented to reflect
 the inputs::
 
 
   .. ipython::
      :suppress:
 
      In [144]: from matplotlib.pylab import *
 
      In [145]: ion()
 
 .. ipython::
    :suppress:
 
    In [144]: from matplotlib.pylab import *
 
    In [145]: ion()
 
 Likewise, you can set ``:doctest:`` or ``:verbatim:`` to apply these
 settings to the entire block.  For example,
 
 .. ipython::
    :verbatim:
 
    In [9]: cd mpl/examples/
    /home/jdhunter/mpl/examples
 
    In [10]: pwd
    Out[10]: '/home/jdhunter/mpl/examples'
 
 
    In [14]: cd mpl/examples/<TAB>
    mpl/examples/animation/        mpl/examples/misc/
    mpl/examples/api/              mpl/examples/mplot3d/
    mpl/examples/axes_grid/        mpl/examples/pylab_examples/
    mpl/examples/event_handling/   mpl/examples/widgets
 
    In [14]: cd mpl/examples/widgets/
    /home/msierig/mpl/examples/widgets
 
    In [15]: !wc *
        2    12    77 README.txt
       40    97   884 buttons.py
       26    90   712 check_buttons.py
       19    52   416 cursor.py
      180   404  4882 menu.py
       16    45   337 multicursor.py
       36   106   916 radio_buttons.py
       48   226  2082 rectangle_selector.py
       43   118  1063 slider_demo.py
       40   124  1088 span_selector.py
      450  1274 12457 total
 
 You can create one or more pyplot plots and insert them with the
 ``@savefig`` decorator.
 
 For more information on @savefig decorator, please refer to the end of this page in Pseudo-Decorators section.
 
 .. ipython::
 
    @savefig plot_simple.png width=4in
    In [151]: plot([1,2,3]);
 
    # use a semicolon to suppress the output
    @savefig hist_simple.png width=4in
    In [151]: hist(np.random.randn(10000), 100);
 
 In a subsequent session, we can update the current figure with some
 text, and then resave
 
 .. ipython::
 
 
    In [151]: ylabel('number')
 
    In [152]: title('normal distribution')
 
    @savefig hist_with_text.png width=4in
    In [153]: grid(True)
 
 You can also have function definitions included in the source.
 
 .. ipython::
 
    In [3]: def square(x):
       ...:     """
       ...:     An overcomplicated square function as an example.
       ...:     """
       ...:     if x < 0:
       ...:         x = abs(x)
       ...:     y = x * x
       ...:     return y
       ...:
 
 Then call it from a subsequent section.
 
 .. ipython::
 
    In [4]: square(3)
    Out [4]: 9
 
    In [5]: square(-2)
    Out [5]: 4
 
 
 Writing Pure Python Code
 ------------------------
 
 Pure python code is supported by the optional argument `python`. In this pure
 python syntax you do not include the output from the python interpreter. The
 following markup::
 
    .. ipython:: python
 
       foo = 'bar'
       print(foo)
       foo = 2
       foo**2
 
 Renders as
 
 .. ipython:: python
 
    foo = 'bar'
    print(foo)
    foo = 2
    foo**2
 
 We can even plot from python, using the savefig decorator, as well as, suppress
 output with a semicolon
 
 .. ipython:: python
 
    @savefig plot_simple_python.png width=4in
    plot([1,2,3]);
 
 For more information on @savefig decorator, please refer to the end of this page in Pseudo-Decorators section.
 
 Similarly, std err is inserted
 
 .. ipython:: python
    :okexcept:
 
    foo = 'bar'
    foo[)
 
 Handling Comments
 ==================
 
 Comments are handled and state is preserved
 
 .. ipython:: python
 
    # comments are handled
    print(foo)
 
 If you don't see the next code block then the options work.
 
 .. ipython:: python
    :suppress:
 
    ioff()
    ion()
 
 Splitting Python statements across lines
 ========================================
 
 Multi-line input is handled.
 
 .. ipython:: python
 
    line = 'Multi\
            line &\
            support &\
            works'
    print(line.split('&'))
 
 Functions definitions are correctly parsed
 
 .. ipython:: python
 
    def square(x):
        """
        An overcomplicated square function as an example.
        """
        if x < 0:
            x = abs(x)
        y = x * x
        return y
 
 And persist across sessions
 
 .. ipython:: python
 
    print(square(3))
    print(square(-2))
 
 Pretty much anything you can do with the ipython code, you can do with
 with a simple python script. Obviously, though it doesn't make sense
 to use the doctest option.
 
+.. _pseudo-decorators:
+
 Pseudo-Decorators
 =================
 
 Here are the supported decorators, and any optional arguments they
 take.  Some of the decorators can be used as options to the entire
 block (eg ``verbatim`` and ``suppress``), and some only apply to the
 line just below them (eg ``savefig``).
 
 @suppress
 
     execute the ipython input block, but suppress the input and output
     block from the rendered output.  Also, can be applied to the entire
     ``.. ipython`` block as a directive option with ``:suppress:``.
 
 @verbatim
 
     insert the input and output block in verbatim, but auto-increment
     the line numbers. Internally, the interpreter will be fed an empty
     string, so it is a no-op that keeps line numbering consistent.
     Also, can be applied to the entire ``.. ipython`` block as a
     directive option with ``:verbatim:``.
 
 @savefig OUTFILE [IMAGE_OPTIONS]
 
     save the figure to the static directory and insert it into the
     document, possibly binding it into a minipage and/or putting
     code/figure label/references to associate the code and the
     figure. Takes args to pass to the image directive (*scale*,
     *width*, etc can be kwargs); see `image options
     <http://docutils.sourceforge.net/docs/ref/rst/directives.html#image>`_
     for details.
 
 @doctest
 
     Compare the pasted in output in the ipython block with the output
     generated at doc build time, and raise errors if they don't
     match. Also, can be applied to the entire ``.. ipython`` block as a
     directive option with ``:doctest:``.
 
 Configuration Options
 =====================
 
 ipython_savefig_dir
 
     The directory in which to save the figures. This is relative to the
     Sphinx source directory. The default is `html_static_path`.
 
 ipython_rgxin
 
     The compiled regular expression to denote the start of IPython input
     lines. The default is `re.compile('In \[(\d+)\]:\s?(.*)\s*')`. You
     shouldn't need to change this.
 
 ipython_rgxout
 
     The compiled regular expression to denote the start of IPython output
     lines. The default is `re.compile('Out\[(\d+)\]:\s?(.*)\s*')`. You
     shouldn't need to change this.
 
 
 ipython_promptin
 
     The string to represent the IPython input prompt in the generated ReST.
     The default is `'In [%d]:'`. This expects that the line numbers are used
     in the prompt.
 
 ipython_promptout
 
     The string to represent the IPython prompt in the generated ReST. The
     default is `'Out [%d]:'`. This expects that the line numbers are used
     in the prompt.
 
 
 Automatically generated documentation
 =====================================
 
 .. automodule:: IPython.sphinxext.ipython_directive