mcs/mcs/namespace.cs

   1 //
   2 // namespace.cs: Tracks namespaces
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2001 Ximian, Inc.
   8 //
   9 using System;
  10 using System.Collections;
  11
  12 namespace Mono.CSharp {
  13
  14         /// <summary>
  15         ///   Keeps track of the namespaces defined in the C# code.
  16         /// </summary>
  17         public class Namespace {
  18                 Namespace parent;
  19                 string name;
  20                 ArrayList using_clauses;
  21                 Hashtable aliases;
  22                 bool decl_found = false;
  23
  24                 /// <summary>
  25                 ///   Constructor Takes the current namespace and the
  26                 ///   name.  This is bootstrapped with parent == null
  27                 ///   and name = ""
  28                 /// </summary>
  29                 public Namespace (Namespace parent, string name)
  30                 {
  31                         this.name = name;
  32                         this.parent = parent;
  33                 }
  34
  35                 /// <summary>
  36                 ///   The qualified name of the current namespace
  37                 /// </summary>
  38                 public string Name {
  39                         get {
  40                                 string pname = parent != null ? parent.Name : "";
  41
  42                                 if (pname == "")
  43                                         return name;
  44                                 else
  45                                         return parent.Name + "." + name;
  46                         }
  47                 }
  48
  49                 /// <summary>
  50                 ///   The parent of this namespace, used by the parser to "Pop"
  51                 ///   the current namespace declaration
  52                 /// </summary>
  53                 public Namespace Parent {
  54                         get {
  55                                 return parent;
  56                         }
  57                 }
  58
  59                 /// <summary>
  60                 ///   When a declaration is found in a namespace,
  61                 ///   we call this function, to emit an error if the
  62                 ///   program attempts to use a using clause afterwards
  63                 /// </summary>
  64                 public void DeclarationFound ()
  65                 {
  66                         decl_found = true;
  67                 }
  68
  69                 /// <summary>
  70                 ///   Records a new namespace for resolving name references
  71                 /// </summary>
  72                 public void Using (string ns)
  73                 {
  74                         if (decl_found){
  75                                 CSharpParser.error (1529, "A using clause must precede all other namespace elements");
  76                                 return;
  77                         }
  78
  79                         if (using_clauses == null)
  80                                 using_clauses = new ArrayList ();
  81
  82                         using_clauses.Add (ns);
  83                 }
  84
  85                 public ArrayList UsingTable {
  86                         get {
  87                                 return using_clauses;
  88                         }
  89                 }
  90
  91                 public void UsingAlias (string alias, string namespace_or_type, Location loc)
  92                 {
  93                         if (aliases == null)
  94                                 aliases = new Hashtable ();
  95
  96                         if (aliases.Contains (alias)){
  97                                 Report.Error (1537, loc, "The using alias `" + alias +
  98                                               "' appeared previously in this namespace");
  99                                 return;
 100                         }
 101
 102                         aliases [alias] = namespace_or_type;
 103                 }
 104
 105                 public string LookupAlias (string alias)
 106                 {
 107                         string value = null;
 108
 109                         // System.Console.WriteLine ("Lookup " + alias + " in " + name);
 110
 111                         if (aliases != null)
 112                                 value = (string) (aliases [alias]);
 113                         if (value == null && Parent != null)
 114                                 value = Parent.LookupAlias (alias);
 115
 116                         return value;
 117                 }
 118
 119                 /// <summary>
 120                 ///   Used to validate that all the using clauses are correct
 121                 ///   after we are finished parsing all the files
 122                 /// </summary>
 123                 public void VerifyUsing ()
 124                 {
 125                         foreach (DictionaryEntry de in using_clauses){
 126                                 if (de.Value == null){
 127                                         string name = (string) de.Key;
 128
 129                                         CSharpParser.error (234, "The type or namespace `" +
 130                                                             name + "' does not exist in the " +
 131                                                             "class or namespace `" + name + "'");
 132                                 }
 133                         }
 134                 }
 135
 136         }
 137 }
 138