1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   5  * This code is free software; you can redistribute it and/or modify it
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   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
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  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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  25 
  26 /**
  27  * <h1>Library for generating Java source code</h1>.
  28  *
  29  * <p>
  30  * CodeModel is a library that allows you to generate Java source
  31  * code in a type-safe fashion.
  32  *
  33  * <p>
  34  * With CodeModel, you build the java source code by first building AST,
  35  * then writing it out as text files that is Java source files.
  36  * The AST looks like this:
  37  *
  38  * <p>
  39  * You bulid this tree mostly from top-down. So, you first create
  40  * a new {@link JDefinedClass} from {@link JCodeModel}, then you
  41  * create a {@link JMethod} from {@link JDefinedClass}, and so on.
  42  *
  43  * <p>
  44  * This design brings the following beneefits:
  45  *
  46  * <ul>
  47  *  <li>source code can be written in random order
  48  *  <li>generated source code nicely imports other classes
  49  *  <li>generated source code is lexically always correct
  50  *      (no unbalanced parenthesis, etc.)
  51  *  <li>code generation becomes relatively type-safe
  52  * </ul>
  53  *
  54  * The price you pay for that is
  55  * increased memory footprint and the generation speed.
  56  * See <a href="#performance">performance section</a> for
  57  * more discussions about the performance and possible improvements.
  58  *
  59  *
  60  * <h2>Using CodeModel</h2>
  61  * <p>
  62  * {@link com.sun.codemodel.internal.JCodeModel} is the entry point to
  63  * the library. See its javadoc for more details about how to use
  64  * CodeModel.
  65  *
  66  *
  67  *
  68  * <h2>Performance</h2>
  69  * <p>
  70  * Generally speaking, CodeModel is expected to be used in
  71  * an environment where the resource constraint is not severe.
  72  * Therefore, we haven't spent much effort in trying to make
  73  * this library lean and mean.
  74  *
  75  * <p>
  76  * That said, we did some benchmark and performance analysis.
  77  * In case anyone is interested in making this library
  78  * better performance wise, here's the findings.
  79  *
  80  * <p>
  81  * {@link List}s {@link Map}s, and other collections take up
  82  * a lot of space. Allocating those things lazily is generally
  83  * a good idea.
  84  *
  85  * <p>
  86  * Compared to template-based code generator, the writing operation
  87  * is slow, as it needs to traverse each AST node. Consider
  88  * pre-encoding tokens (like 'public') to the target encoding,
  89  * and consider exploting the subtree equivalence.
  90  *
  91  */
  92 package com.sun.codemodel.internal;
  93 
  94 import java.util.List;
  95 import java.util.Map;