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This package and its subpackages contain the Falcon compiler.

<p>
The Falcon compiler compiles Flex code consisting of <code>.mxml</code>
<code>.as</code>, <code>.css</code>, <code>.fxg</code>, and
<code>.properties</code> files into SWF and SWC files.
<p>

<p>
The main entry point for compiling a SWF is in the <code>MXMLC</code> class
in the package <code>org.apache.flex.compiler.clients</code>.
The main entry point for compiling a SWC is in the <code>COMPC</code> class
in the same package.
The corresponding Ant tasks are in the package <code>org.apache.flex.compiler.ant</code>.
</p>

<p>
The <code>org.apache.flex.compiler</code> package makes use of the libraries
in the <code>org.apache.flex.abc</code>, <code>org.apache.flex.swf</code>,
and <code>org.apache.flex.swc</code> packages to read and write the ABC, SWF,
and SWC formats. However, these support libraries are independent of the compiler.
</p>

<p>
Falcon is a large body of code but it is organized around ten core concepts,
with a subpackage for each one:
</p>

<table border="1" cellspacing="0" cellpadding="3">
	<tr>
		<td>Workspace</td>
		<td><code>org.apache.flex.compiler.workspaces</code></td>
		<td>The root object of the compiler's data structures. Owns projects to be compiled.</td>
	</tr>
	<tr>
		<td>Project</td>
		<td><code>org.apache.flex.compiler.projects</code></td>
		<td>Owns compilation units to be compiled into one or more targets.</td>
	</tr>
	<tr>
		<td>Target</td>
		<td><code>org.apache.flex.compiler.targets</code></td>
		<td>Manages the compilation of a set of compilation units into a SWF or SWC.</td>
	</tr>
	<tr>
		<td>Compilation Unit</td>
		<td><code>org.apache.flex.compiler.units</code></td>
		<td>Manages the compilation of a single file.
		This typically involves building an AST and a file scope,
		performing semantic analysis to discover problems,
		and code-generating ABC for a <code>DoABC</code> SWF tag.</td>
	</tr>
	<tr>
		<td>AST</td>
		<td><code>org.apache.flex.compiler.tree</code></td>
		<td>Represents almost every detail of a source file as a tree of nodes.</td>
	</tr>
	<tr>
		<td>Scope</td>
		<td><code>org.apache.flex.compiler.scopes</code></td>
		<td>Organizes definitions -- named things declared in source code --
		in a hierarchy that reflects the block structure of the source file.
		Scopes and definitions comprise a symbol table that allow
		AST nodes representing identifiers in the source code
	    to be resolved to definitions (i.e., what they mean).
		A file scope contains the definitions defined with a single file.
		A project scope contains definitions that are visible between files.
	</tr>
	<tr>
		<td>Definition</td>
		<td><code>org.apache.flex.compiler.definitions</code></td>
		<td>Represents a named object in a scope,
		such as a class, interface, function, variable, etc.</td>
	</tr>
	<tr>
		<td>Semantic Analysis</td>
		<td><code>org.apache.flex.compiler.analysis</code></td>
		<td>Resolves identifier nodes in an AST to definitions in a scope
		(and quite a bit more.)</td>
	</tr>
	<tr>
		<td>Problem</td>
		<td><code>org.apache.flex.compiler.problems</code></td>
		<td>Represents an error or warning.
		Most problems are found during semantic analysis.</td>
	</tr>
	<tr>
		<td>Code Generation</td>
		<td><code>org.apache.flex.compiler.codegen</code></td>
		<td>Reduces an AST to ABC, using scopes and definitions
		to understand what each node means.
		The bulk of code generation is handled by a BURM (Bottom-Up Rewrite Machine).</td>
	</tr>
</table>

<p>
For more information, see the description of each of these packages.
</p>

<p>
The compiler code is organized into "external" and "internal" packages.
The internal packages are all within <code>org.apache.flex.compiler.internal</code>.
For example, <code>org.apache.flex.compiler.definitions</code> is an external package
that contains the definition interfaces for clients of the compiler to use;
<code>org.apache.flex.compiler.internal.definitions</code> is its internal counterpart
that contains the definition classes that the compiler itself creates.
Clients should never use code in an internal package; if it becomes necessary to do so,
the code should be moved to an external package.
The distinction can be important: in the case of definitions, for example,
the methods in the interfaces are guaranteed to be safe to call
from multiple threads, while the methods in the classes are not.
</p>

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