Adds Variable declaration.

7 files changed, 315 insertions, 18 deletions

diff --git a/src/core/src/tonkadur/fate/v1/error/UnknownDictionaryFieldException.java b/src/core/src/tonkadur/fate/v1/error/UnknownDictionaryFieldException.java
index dd3e67d..aa1ff70 100644
--- a/src/core/src/tonkadur/fate/v1/error/UnknownDictionaryFieldException.java
+++ b/src/core/src/tonkadur/fate/v1/error/UnknownDictionaryFieldException.java
@@ -47,14 +47,13 @@ public class UnknownDictionaryFieldException extends ParsingError
       sb.append(field_name);
       sb.append("' for dictionary type '");
       sb.append(dict.get_name());
-      sb.append("' at ");
-      sb.append(origin.get_location().toString());
-      sb.append(".");
+      sb.append("'.");
       sb.append(System.lineSeparator());
       sb.append("Available fields are:");
 
       for (final Map.Entry<String, Type> field: dict.get_fields())
       {
+         sb.append(System.lineSeparator());
          sb.append("- ");
          sb.append(field.getKey());
          sb.append(": ");
diff --git a/src/core/src/tonkadur/fate/v1/error/UnknownVariableScopeException.java b/src/core/src/tonkadur/fate/v1/error/UnknownVariableScopeException.java
new file mode 100644
index 0000000..129a789
--- /dev/null
+++ b/src/core/src/tonkadur/fate/v1/error/UnknownVariableScopeException.java
@@ -0,0 +1,55 @@
+package tonkadur.fate.v1.error;
+
+import tonkadur.error.ErrorLevel;
+
+import tonkadur.parser.Origin;
+import tonkadur.parser.ParsingError;
+
+import tonkadur.fate.v1.lang.VariableScope;
+
+public class UnknownVariableScopeException extends ParsingError
+{
+   /***************************************************************************/
+   /**** MEMBERS **************************************************************/
+   /***************************************************************************/
+   protected final String name;
+
+   /***************************************************************************/
+   /**** PUBLIC ***************************************************************/
+   /***************************************************************************/
+   public UnknownVariableScopeException
+   (
+      final Origin origin,
+      final String name
+   )
+   {
+      super(ErrorLevel.ERROR, ErrorCategory.INVALID_USE, origin);
+      this.name = name;
+   }
+
+   @Override
+   public String toString ()
+   {
+      final StringBuilder sb = new StringBuilder();
+
+      sb.append(origin.toString());
+      sb.append(" ");
+      sb.append(error_category.toString());
+      sb.append(System.lineSeparator());
+
+      sb.append("Unknown variable scope '");
+      sb.append(name);
+      sb.append("'.");
+      sb.append(System.lineSeparator());
+      sb.append("Available fields are:");
+
+      for (final String scope: VariableScope.get_available_scopes())
+      {
+         sb.append(System.lineSeparator());
+         sb.append("- ");
+         sb.append(scope);
+      }
+
+      return sb.toString();
+   }
+}
diff --git a/src/core/src/tonkadur/fate/v1/lang/Event.java b/src/core/src/tonkadur/fate/v1/lang/Event.java
index b917ebf..d762c71 100644
--- a/src/core/src/tonkadur/fate/v1/lang/Event.java
+++ b/src/core/src/tonkadur/fate/v1/lang/Event.java
@@ -127,7 +127,7 @@ public class Event extends DeclaredEntity
                      protected Boolean lambda (final Type a, final Type b)
                      {
                         return
-                           new Boolean(a.is_incompatible_with_declaration(b));
+                           new Boolean(a.can_be_used_as(b));
                      }
                   }.merge(signature, e.signature)
                );
@@ -171,8 +171,4 @@ public class Event extends DeclaredEntity
 
       return sb.toString();
    }
-
-   /***************************************************************************/
-   /**** PROTECTED ************************************************************/
-   /***************************************************************************/
 }
diff --git a/src/core/src/tonkadur/fate/v1/lang/Variable.java b/src/core/src/tonkadur/fate/v1/lang/Variable.java
new file mode 100644
index 0000000..3e17d61
--- /dev/null
+++ b/src/core/src/tonkadur/fate/v1/lang/Variable.java
@@ -0,0 +1,136 @@
+package tonkadur.fate.v1.lang;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import tonkadur.functional.Merge;
+
+import tonkadur.parser.Context;
+import tonkadur.parser.Location;
+import tonkadur.parser.Origin;
+
+import tonkadur.fate.v1.lang.meta.DeclaredEntity;
+
+public class Variable extends DeclaredEntity
+{
+   protected static final Variable ANY;
+
+   static
+   {
+      ANY =
+         new Variable
+         (
+            new Origin(new Context(""), Location.BASE_LANGUAGE),
+            VariableScope.ANY,
+            Type.ANY,
+            /*
+             * Use of a space necessary to avoid conflicting with a user created
+             * type.
+             */
+            "undetermined variable"
+         );
+   }
+
+   public static Variable value_on_missing ()
+   {
+      return ANY;
+   }
+
+   @Override
+   public /* static */ String get_type_name ()
+   {
+      return "Variable";
+   }
+
+
+   /***************************************************************************/
+   /**** MEMBERS **************************************************************/
+   /***************************************************************************/
+   protected final VariableScope scope;
+   protected final Type type;
+
+   /***************************************************************************/
+   /**** PUBLIC ***************************************************************/
+   /***************************************************************************/
+
+   /**** Constructors *********************************************************/
+   public Variable
+   (
+      final Origin origin,
+      final VariableScope scope,
+      final Type type,
+      final String name
+   )
+   {
+      super(origin, name);
+
+      this.scope = scope;
+      this.type = type;
+   }
+
+   /**** Accessors ************************************************************/
+   public Type get_type ()
+   {
+      return type;
+   }
+
+   @Override
+   public DeclaredEntity generate_comparable_to (final DeclaredEntity de)
+   {
+      final VariableScope new_scope;
+      final Type new_type;
+      final Variable v;
+
+      if (!(de instanceof Variable))
+      {
+         return ANY;
+      }
+
+      v = (Variable) de;
+
+      new_scope = scope.generate_compatible_with(v.scope);
+      new_type = (Type) type.generate_comparable_to(v.type);
+
+      return new Variable(origin, new_scope, new_type, name);
+   }
+
+   /**** Misc. ****************************************************************/
+   @Override
+   public boolean is_incompatible_with_declaration (final DeclaredEntity de)
+   {
+      if (de instanceof Variable)
+      {
+         final Variable v;
+
+         v = (Variable) de;
+
+         return
+            (
+               (!scope.equals(v.scope))
+               || !type.can_be_used_as(v.type)
+            );
+      }
+
+      return true;
+   }
+
+   @Override
+   public String toString ()
+   {
+      final StringBuilder sb = new StringBuilder();
+
+      sb.append("(");
+      sb.append(scope.toString());
+      sb.append(" ");
+      sb.append(type.get_name());
+      sb.append(" Variable ");
+      sb.append(name);
+      sb.append(")");
+
+      return sb.toString();
+   }
+
+   /***************************************************************************/
+   /**** PROTECTED ************************************************************/
+   /***************************************************************************/
+}
diff --git a/src/core/src/tonkadur/fate/v1/lang/VariableScope.java b/src/core/src/tonkadur/fate/v1/lang/VariableScope.java
new file mode 100644
index 0000000..7f42fa6
--- /dev/null
+++ b/src/core/src/tonkadur/fate/v1/lang/VariableScope.java
@@ -0,0 +1,88 @@
+package tonkadur.fate.v1.lang;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.HashSet;
+
+/*
+ * Yes, it *could* have been an enum. Except that you can't extend enums, making
+ * them inadequate for anything that has even the slightest chance of needing to
+ * be extended at some point in the future. In other words, they're inadequate
+ * for anything but very rare corner cases (days in week, for example).
+ * Tonkadur wants extension support, ergo, no enums in Tonkadur.
+ *
+ * The use of a collection to decode them stems from the same reason (can't
+ * override static methods).
+ */
+public class VariableScope
+{
+   public static final VariableScope ANY;
+
+   protected static final Map<String, VariableScope> from_name;
+   public static final VariableScope LOCAL;
+   public static final VariableScope GLOBAL;
+
+   static
+   {
+      from_name = new HashMap<String, VariableScope>();
+
+      ANY = new VariableScope("unknown scope", null);
+      GLOBAL = new VariableScope("global", null);
+      LOCAL = new VariableScope("local", GLOBAL);
+   }
+
+   public static VariableScope value_of (final String string)
+   {
+      return from_name.get(string);
+   }
+
+   public static Set<String> get_available_scopes ()
+   {
+      return from_name.keySet();
+   }
+
+   protected final String name;
+   protected final Set<VariableScope> more_restrictive_than;
+
+   protected VariableScope (final String name, final VariableScope parent)
+   {
+      this.name = name;
+
+      more_restrictive_than = new HashSet<VariableScope>();
+
+      if (parent != null)
+      {
+         more_restrictive_than.addAll(parent.more_restrictive_than);
+         more_restrictive_than.add(parent);
+      }
+
+      from_name.put(name, this);
+   }
+
+   public VariableScope generate_compatible_with (final VariableScope other)
+   {
+      if (other.equals(this))
+      {
+         return this;
+      }
+
+      if (other.more_restrictive_than.contains(this))
+      {
+         if (this.more_restrictive_than.contains(other))
+         {
+            return ANY;
+         }
+
+         return other;
+      }
+
+      return this;
+   }
+
+   @Override
+   public String toString ()
+   {
+      return name;
+   }
+}
diff --git a/src/core/src/tonkadur/fate/v1/lang/World.java b/src/core/src/tonkadur/fate/v1/lang/World.java
index 43feb5f..8419b06 100644
--- a/src/core/src/tonkadur/fate/v1/lang/World.java
+++ b/src/core/src/tonkadur/fate/v1/lang/World.java
@@ -21,7 +21,7 @@ public class World
 //   protected final DeclarationCollection<Sequence> sequences;
 //   protected final DeclarationCollection<TextEffect> text_effects;
    protected final DeclarationCollection<Type> type_collection;
-//   protected final DeclarationCollection<Variable> variables;
+   protected final DeclarationCollection<Variable> variable_collection;
 
    /***************************************************************************/
    /**** PUBLIC ***************************************************************/
@@ -39,7 +39,8 @@ public class World
       //text_effects = new DeclarationCollection<TextEffect>();
       type_collection =
          new DeclarationCollection<Type>(Type.value_on_missing());
-      //variables = new DeclarationCollection<Variable>();
+      variable_collection =
+         new DeclarationCollection<Variable>(Variable.value_on_missing());
 
       add_base_types();
    }
@@ -61,16 +62,21 @@ public class World
       loaded_files.add(name);
    }
 
-   public DeclarationCollection<Type> types()
+   public DeclarationCollection<Type> types ()
    {
       return type_collection;
    }
 
-   public DeclarationCollection<Event> events()
+   public DeclarationCollection<Event> events ()
    {
       return event_collection;
    }
 
+   public DeclarationCollection<Variable> variables ()
+   {
+      return variable_collection;
+   }
+
    /**** Misc. ****************************************************************/
    @Override
    public String toString ()
@@ -103,6 +109,12 @@ public class World
       sb.append(System.lineSeparator());
       sb.append(System.lineSeparator());
 
+      sb.append("Variable: ");
+      sb.append(System.lineSeparator());
+      sb.append(variable_collection.toString());
+      sb.append(System.lineSeparator());
+      sb.append(System.lineSeparator());
+
       sb.append(")");
 
       return sb.toString();
diff --git a/src/core/src/tonkadur/fate/v1/parser/FateParser.g4 b/src/core/src/tonkadur/fate/v1/parser/FateParser.g4
index 27ff773..9d30b0f 100644
--- a/src/core/src/tonkadur/fate/v1/parser/FateParser.g4
+++ b/src/core/src/tonkadur/fate/v1/parser/FateParser.g4
@@ -9,11 +9,13 @@ options
 {
    package tonkadur.fate.v1.parser;
 
-   import tonkadur.error.Error;
+   import tonkadur.error.ErrorManager;
 
    import tonkadur.parser.Context;
    import tonkadur.parser.Origin;
 
+   import tonkadur.fate.v1.error.UnknownVariableScopeException;
+
    import tonkadur.fate.v1.lang.*;
    import tonkadur.fate.v1.lang.meta.*;
 }
@@ -71,11 +73,10 @@ first_level_fate_instr:
 
    | DECLARE_VARIABLE_KW scope=WORD WS+ type=WORD WS+ name=WORD R_PAREN
    {
-   /*
       final Origin start_origin, scope_origin, type_origin;
-      final VariableScope variable_scope;
       final Type variable_type;
       final Variable new_variable;
+      VariableScope variable_scope;
 
       start_origin =
          CONTEXT.get_origin_at
@@ -98,8 +99,19 @@ first_level_fate_instr:
             ($type.getCharPositionInLine())
          );
 
-      variable_scope = VariableScope.value_of(scope_origin, ($scope.text));
-      variable_type = WORLD.types().get(($type.text));
+      variable_scope = VariableScope.value_of(($scope.text));
+
+      if (variable_scope == null)
+      {
+         ErrorManager.handle
+         (
+            new UnknownVariableScopeException(scope_origin, ($scope.text))
+         );
+
+         variable_scope = VariableScope.ANY;
+      }
+
+      variable_type = WORLD.types().get(type_origin, ($type.text));
       new_variable =
          new Variable
          (
@@ -110,7 +122,6 @@ first_level_fate_instr:
          );
 
       WORLD.variables().add(new_variable);
-   */
    }
 
    | DECLARE_TEXT_EFFECT_KW params=word_list name=WORD R_PAREN