@author Richard Carlsson <richardc@it.uu.se>
@copyright 1997-2004 Richard Carlsson
@version {@vsn}
@title Erlang Syntax Tools

@doc This package contains modules for handling abstract Erlang syntax
trees, in a way that is compatible with the "parse trees" of the
standard library module `erl_parse', together with utilities for reading
source files in unusual ways and pretty-printing syntax trees. Also
included is an amazing module merger and renamer called Igor, as well as
an automatic code-cleaner.

<p>The abstract layer (defined in {@link erl_syntax}) is nicely
structured and the node types are context-independent. The layer makes
it possible to transparently attach source-code comments and user
annotations to nodes of the tree. Using the abstract layer makes
applications less sensitive to changes in the {@link //stdlib/erl_parse}
data structures, only requiring the {@link erl_syntax} module to be
up-to-date.</p>

<p>The pretty printer {@link erl_prettypr} is implemented on top of the
library module {@link prettypr}: this is a powerful and flexible generic
pretty printing library, which is also distributed separately.</p>

<p>For a short demonstration of parsing and pretty-printing, simply
compile the included module <a
href="../examples/demo.erl"><code>demo.erl</code></a>, and execute
<code>demo:run()</code> from the Erlang shell. It will compile the
remaining modules and give you further instructions.</p>

<p>Also try the {@link erl_tidy} module, as follows:
<pre>
    erl_tidy:dir("any-erlang-source-dir", [test, old_guard_tests]).</pre>
("<code>test</code>" assures that no files are modified).</p>

<p>News in 1.4:
<ul>
  <li>Added support for {@link erl_syntax:cond_expr/1. cond-expressions},
      {@link erl_syntax:try_expr/4. try-expressions} and
      {@link erl_syntax:class_qualifier/2. class-qualifier patterns}.</li>
  <li>Added support for parameterized modules.</li>
  <li>{@link igor. Igor} is officially included.</li>
  <li>Quick-parse functionality added to {@link epp_dodger}.</li>
</ul>
</p>

<p>News in 1.3:
<ul>
  <li>Added support for qualified names (as used by "packages").</li>
  <li>Various internal changes.</li>
</ul>
</p>

<p>News in 1.2:
<ul>
  <li>HTML Documentation (generated with EDoc).</li>
  <li>A few bug fixes and some minor interface changes (sorry for any
    inconvenience).</li>
</ul>
</p>

<p>News in 1.1:
<ul>
  <li>Module {@link erl_tidy}: check or tidy either a single module, or a
    whole directory tree recursively. Rewrites and reformats the code
    without losing comments or expanding macros. Safe mode allows
    generating reports without modifying files.</li>
  <li>Module {@link erl_syntax_lib}: contains support functions for easier
    analysis of the source code structure.</li>
  <li>Module {@link epp_dodger}: Bypasses the Erlang preprocessor - avoids
    macro expansion, file inclusion, conditional compilation, etc.
    Allows you to find/modify particular definitions/applications of
    macros, and other things previously not possible.</li>
</ul>
</p>