Documents pretty command.

doc/advopt.txt

@@ -12,6 +12,7 @@ Advanced commands:
                             module dependency graph
   //dump                    dump all defined conditionals and search paths
   //check                   checks the project for syntax and semantic
+  //pretty                  homogenizes source code style
   //idetools                compiler support for IDEs: possible options:
     --track:FILE,LINE,COL   track a file/cursor position
     --trackDirty:DIRTY_FILE,ORIG_FILE,LINE,COL

doc/nimrodc.txt

@@ -540,6 +540,58 @@ in C/C++).
 **Note**: This pragma will not exist for the LLVM backend.
 
 
+Source code style
+=================
+
+Nimrod allows you to `mix freely case and underscores as identifier separators
+<manual.html#identifiers-keywords>`_, so variables named ``MyPrecioussInt`` and
+``my_preciouss_int`` are equivalent:
+
+.. code-block:: Nimrod
+  var MyPrecioussInt = 3
+  # Following line compiles fine!
+  echo my_preciouss_int
+
+Since this can lead to many variants of the same source code (you can use
+`nimgrep <nimgrep.html>`_ instead of your typical ``grep`` to ignore style
+problems) the compiler provides the command ``pretty`` to help unifying the
+style of source code.  Running ``nimrod pretty ugly_test.nim`` with this
+example will generate a secondary file named ``ugly_test.pretty.nim`` with the
+following content:
+
+.. code-block:: Nimrod
+  var MyPrecioussInt = 3
+  # Following line compiles fine!
+  echo MyPrecioussInt
+
+During execution the ``pretty`` command will also run on Nimrod's standard
+library, since it doesn't differentiate the standard library as something
+special, and hence will warn of many *errors* which are out of your hand to
+fix, creating respective ``.pretty.nim`` files all the way. You can ignore
+these errors if they don't belong to your source and simply compare your
+original version to the new pretty one. In fact, running ``pretty`` on our test
+file will show the following::
+
+  Hint: ugly_test [Processing]
+  ugly_test.nim(1, 4) Error: name should be: myPrecioussInt
+  ugly_test.nim(1, 4) Error: name should be: myPrecioussInt
+
+At the moment ``pretty`` will homogenize the style of symbols but will leave
+important changes for you to review. In this case the command is warning that a
+variable name should not start with a capital letter, which is usually reserved
+to `object types <tut2.html#objects>`_. To learn about the accepted `camel case
+style <https://en.wikipedia.org/wiki/Camelcase>`_ read `Coding Guidelines in
+the Internals of Nimrod Compiler <intern.html#coding-guidelines>`_ or `Coding
+Guidelines <https://github.com/Araq/Nimrod/wiki/Coding-Guidelines>`_ and `NEP 1
+: Style Guide for Nimrod Code
+<https://github.com/Araq/Nimrod/wiki/NEP-1-:-Style-Guide-for-Nimrod-Code>`_
+from the Nimrod `GitHub wiki<https://github.com/Araq/Nimrod/wiki>`_.
+
+This command is safe to run because it will never attempt to overwrite your
+existing sources, but the respective ``.pretty.nim`` files **will** be
+overwritten without notice.
+
+
 DynlibOverride
 ==============