modeladditions.scala

来自「JAVA 语言的函数式编程扩展」· SCALA 代码 · 共 202 行

/* NSC -- new Scala compiler
 * Copyright 2007-2008 LAMP/EPFL
 * @author  Sean McDirmid
 */
// $Id: ModelAdditions.scala 14416 2008-03-19 01:17:25Z mihaylov $

package scala.tools.nsc.doc

/**
 *  @author Stephane Micheloud, Sean McDirmid
 *  @version 1.0
 */
class ModelAdditions(val global: Global) {
  import global._
  import definitions._
  def addition(sym: global.Symbol) {}

  addition(AllClass);
  comments(AllClass) = """
    <p>
      Class <code>Nothing</code> (previously named <code>All</code> in
      <a href="http://scala-lang.org" target="_top">Scala</a> 2.2.0 and
      older versions) is - together with class <a href="Null.html">
      <code>Null</code></a> - at the bottom of the
      <a href="http://scala-lang.org" target="_top">Scala</a> type
      hierarchy.
    </p>
    <p>
      Type <code>Nothing</code> is a subtype of every other type
      (including <a href="Null.html"><code>Null</code></a>); there
      exist <em>no instances</em> of this type. Even though type
      <code>Nothing</code> is empty, it is nevertheless useful as a
      type parameter. For instance, the <a href="http://scala-lang.org"
      target="_top">Scala</a> library defines a value
      <a href="Nil$object.html"><code>Nil</code></a> of type
      <code><a href="List.html">List</a>[Nothing]</code>. Because lists
      are covariant in <a href="http://scala-lang.org" target="_top">Scala</a>,
      this makes <a href="Nil$object.html"><code>Nil</code></a> an
      instance of <code><a href="List.html">List</a>[T]</code>, for
      any element type <code>T</code>.
    </p>"""

   addition(AllRefClass);
   comments(AllRefClass) = """
     <p>
       Class <code>Null</code> (previously named <code>AllRef</code> in
       <a href="http://scala-lang.org" target="_top">Scala</a> 2.2.0 and
       older versions) is - together with class <a href="Nothing.html">
       <code>Nothing</code> - at the bottom of the
       <a href="http://scala-lang.org" target="_top">Scala</a> type
       hierarchy.
     </p>
     <p>
       Type <code>Null</code> is a subtype of all reference types; its
       only instance is the <code>null</code> reference.
       Since <code>Null</code> is not a subtype of value types,
       <code>null</code> is not a member of any such type. For instance,
       it is not possible to assign <code>null</code> to a variable of
       type <a href="Int.html"><code>Int</code></a>.
     </p>"""

   addition(AnyClass);
   comments(AnyClass) = """
     <p>
       Class <code>Any</code> is the root of the <a
       href="http://scala-lang.org/"
       target="_top">Scala</a> class hierarchy. Every class in a
       <a href="http://scala-lang.org/" target="_top">Scala</a> execution
       environment inherits directly or indirectly from this class.
       Class <code>Any</code> has two direct subclasses:
       <a href="AnyRef.html"><code>AnyRef</code></a> and
       <a href="AnyVal.html"><code>AnyVal</code></a>.
     </p>"""

  addition(Object_isInstanceOf);
  comments(Object_isInstanceOf) = """
    <p>
      The method <code>isInstanceOf</code> is the pendant of the Java
      operator <code>instanceof</code>.
    </p>
    @see <ul><li>Java Language Specification (2<sup>nd</sup> Ed.):
         <a href="http://java.sun.com/docs/books/jls/second_edition/html/expressions.doc.html#80289"
         target="_top">Operator <code>instanceof</code></a>.</li></ul>
    """

   addition(Object_synchronized);
   comments(Object_synchronized) = """
     <p>
       To make your programs thread-safe, you must first identify what
       data will be shared across threads. If you are writing data that
       may be read later by another thread, or reading data that may
       have been written by another thread, then that data is shared,
       and you must synchronize when accessing it.
     </p>
     @see <ul><li>The Java Tutorials:
         <a href="http://java.sun.com/docs/books/tutorial/essential/concurrency/sync.html"
         target="_top">Synchronization</a>.</li>
         <li> IBM developerWorks:
         <a href="http://www-128.ibm.com/developerworks/java/library/j-threads1.html"
         target="_top">Synchronization is not the enemy</a>.</li></ul>
    """

   addition(AnyRefClass);
   comments(AnyRefClass) = """
     <p>
       Class <code>AnyRef</code> is the root class of all
       <em>reference types</em>.
     </p>"""

   addition(AnyValClass);
   comments(AnyValClass) = """
     <p>
       Class <code>AnyVal</code> is the root class of all
       <em>value types</em>.
     </p>
     <p>
       <code>AnyVal</code> has a fixed number subclasses, which
       describe values which are not implemented as objects in the
       underlying host system.
     </p>
     <p>
       Classes <a href="Double.html"><code>Double</code></a>,
       <a href="Float.html"><code>Float</code></a>,
       <a href="Long.html"><code>Long</code></a>,
       <a href="Int.html"><code>Int</code></a>,
       <a href="Char.html"><code>Char</code></a>,
       <a href="Short.html"><code>Short</code></a>, and
       <a href="Byte.html"><code>Byte</code></a> are together called
       <em>numeric value types</em>.
       Classes <a href="Byte.html"><code>Byte</code></a>,
       <a href="Short.html"><code>Short</code></a>, or
       <a href="Char.html"><code>Char</code></a>
       are called <em>subrange types</em>. Subrange types, as well as
       <a href="Int.html"><code>Int</code></a> and
       <a href="Long.html"><code>Long</code></a> are called
       <em>integer types</em>, whereas
       <a href="Float.html"><code>Float</code></a> and
       <a href="Double.html"><code>Double</code></a> are called
       <em>floating point types</em>.
     </p>"""

   addition(BooleanClass)
   comments(BooleanClass) = """
    <p>
      Class <code>Boolean</code> has only two values: <code>true</code>
      and <code>false</code>.
    </p>"""

   def numericValDescr(sym: Symbol) = {
     val maxValue = "MAX_" + sym.name.toString().toUpperCase()
     val minValue = "MIN_" + sym.name.toString().toUpperCase()
     addition(sym)
     comments(sym) = """
       <p>
         Class <code>""" + sym.name + """ </code> belongs to the value
         classes whose instances are not represented as objects by the
         underlying host system. All value classes inherit from class
         <a href="AnyVal.html"><code>AnyVal</code></a>.
       </p>
       <p>
         Values <code>""" + maxValue + """</code> and <code>""" + minValue + """</code>
         are in defined in object <a href="Math$object.html">scala.Math</a>.
       </p>"""
   }
   (ByteClass :: CharClass :: DoubleClass :: LongClass :: 
    FloatClass :: IntClass :: ShortClass :: Nil).foreach(numericValDescr);

   addition(UnitClass);
   comments(UnitClass) = """
     <p>
       Class <code>Unit</code> has only one value: <code>()</code>.
     </p>"""

   addition(UnitClass);
/*
   def boxedValDescr(what: String) = {
     val sym = definitions.getClass("java.lang." + what)
     addition(sym)
     comments(sym) = """
       <p>
         Class <code>""" + sym.name + """</code> implements the
         boxing/unboxing from/to value types.
       </p>
       <p>
         Boxing and unboxing enable value types to be treated as objects;
         they provide a unified view of the type system wherein a value
         of any type can ultimately be treated as an object.
       </p>"""
   };
   //("Float" :: "Long" :: "Number" :: "Integer" :: Nil).foreach(boxedValDescr);
*/
   object exceptions extends collection.jcl.TreeMap[String,(Symbol,String)] {
     def f(name: String) {
       this("Predef." + name) = (definitions.PredefModule, name)
     }
     f("IndexOutOfBoundsException")
     f("NoSuchElementException")
     f("NullPointerException")
     f("UnsupportedOperationException")
   }
}