Adds external variables.

6 files changed, 90 insertions, 22 deletions

diff --git a/data/examples/blackjack/global.fate b/data/examples/blackjack/global.fate
index 16574e6..c49642d 100644
--- a/data/examples/blackjack/global.fate
+++ b/data/examples/blackjack/global.fate
@@ -34,3 +34,5 @@
       )
    )
 )
+
+(declare_input_event escape)
diff --git a/data/examples/blackjack/main.fate b/data/examples/blackjack/main.fate
index 342a663..67b70b1 100644
--- a/data/examples/blackjack/main.fate
+++ b/data/examples/blackjack/main.fate
@@ -24,16 +24,18 @@ Just between you and me, someone left those laying around, they aren't mine.
 Now, you're all set to go... unless you don't know how to play?
 
 (player_choice
-   (option
-      ( As it happens, I do not. )
+   (option ( As it happens, I do not. )
       (visit rules_of_blackjack)
       (text_effect action_description
          You leave the counter and approach one of the tables.
       )
       (visit play_a_game)
    )
-   (option
-      ( I am familiar with BlackJack. )
+   (event (escape)
+      You suddenly disappear.
+      (end)
+   )
+   (option ( I am familiar with BlackJack. )
       (text_effect action_description
          You leave the counter and approach one of the tables.
       )
diff --git a/src/core/src/tonkadur/fate/v1/lang/Variable.java b/src/core/src/tonkadur/fate/v1/lang/Variable.java
index 3a8b761..bb72565 100644
--- a/src/core/src/tonkadur/fate/v1/lang/Variable.java
+++ b/src/core/src/tonkadur/fate/v1/lang/Variable.java
@@ -28,7 +28,8 @@ public class Variable extends DeclaredEntity
              * Use of a space necessary to avoid conflicting with a user created
              * type.
              */
-            "undetermined variable"
+            "undetermined variable",
+            true
          );
    }
 
@@ -48,6 +49,7 @@ public class Variable extends DeclaredEntity
    /**** MEMBERS **************************************************************/
    /***************************************************************************/
    protected final Type type;
+   protected final boolean is_external;
 
    /***************************************************************************/
    /**** PUBLIC ***************************************************************/
@@ -58,12 +60,14 @@ public class Variable extends DeclaredEntity
    (
       final Origin origin,
       final Type type,
-      final String name
+      final String name,
+      final boolean is_external
    )
    {
       super(origin, name);
 
       this.type = type;
+      this.is_external = is_external;
    }
 
    /**** Accessors ************************************************************/
@@ -72,6 +76,11 @@ public class Variable extends DeclaredEntity
       return type;
    }
 
+   public boolean is_external ()
+   {
+      return is_external;
+   }
+
    @Override
    public DeclaredEntity generate_comparable_to (final DeclaredEntity de)
    {
@@ -87,7 +96,7 @@ public class Variable extends DeclaredEntity
 
       new_type = (Type) type.generate_comparable_to(v.type);
 
-      return new Variable(origin, new_type, name);
+      return new Variable(origin, new_type, name, v.is_external());
    }
 
    /**** Misc. ****************************************************************/
@@ -100,7 +109,9 @@ public class Variable extends DeclaredEntity
 
          v = (Variable) de;
 
-         return !type.can_be_used_as(v.type);
+         return
+            !type.can_be_used_as(v.type)
+            || (is_external() != v.is_external());
       }
 
       return true;
@@ -115,6 +126,12 @@ public class Variable extends DeclaredEntity
       sb.append(type.get_name());
       sb.append(" Variable ");
       sb.append(name);
+
+      if (is_external())
+      {
+         sb.append(" (external)");
+      }
+
       sb.append(")");
 
       return sb.toString();
diff --git a/src/core/src/tonkadur/fate/v1/parser/FateLexer.g4 b/src/core/src/tonkadur/fate/v1/parser/FateLexer.g4
index b1dbd75..29048d2 100644
--- a/src/core/src/tonkadur/fate/v1/parser/FateLexer.g4
+++ b/src/core/src/tonkadur/fate/v1/parser/FateLexer.g4
@@ -42,6 +42,7 @@ DECLARE_INPUT_EVENT_TYPE_KW: L_PAREN ('declare'|'define'|'def')US'input'US'event
 DECLARE_TEXT_EFFECT_KW: L_PAREN ('declare'|'define'|'def')US'text'US'effect' SEP+;
 DECLARE_VARIABLE_KW: L_PAREN 'global' SEP+;
 LOCAL_KW: L_PAREN 'local' SEP+;
+EXTERNAL_KW: L_PAREN 'extern'('al'?) SEP+;
 DEFAULT_KW: L_PAREN 'default' SEP+;
 DEFINE_SEQUENCE_KW: L_PAREN ('declare'|'define'|'def')US(('seq'('uence')?)|('proc'('edure'?))) SEP+;
 DIVIDE_KW: L_PAREN ('divide'|'/'|'div') SEP+;
@@ -115,7 +116,7 @@ PUSH_RIGHT_KW: L_PAREN 'push'US'right' SEP+;
 IMP_PUSH_RIGHT_KW: L_PAREN 'push'US'right!' SEP+;
 PLAYER_CHOICE_KW: L_PAREN ('choice'|'user'US'choice'|'player'US'choice') SEP+;
 PLAYER_OPTION_KW: L_PAREN ('option'|'user'US'option'|'player'US'option') SEP+;
-PLAYER_EVENT_KW: L_PAREN ('event'|'user'US'event'|'player'US'event') SEP+;
+PLAYER_EVENT_KW: L_PAREN ('user'US'event'|'player'US'event') SEP+;
 PLUS_KW: L_PAREN ('plus'|'+') SEP+;
 POWER_KW: L_PAREN ('power'|'^'|'**'|'pow') SEP+;
 RANGE_KW: L_PAREN 'range' SEP+;
diff --git a/src/core/src/tonkadur/fate/v1/parser/FateParser.g4 b/src/core/src/tonkadur/fate/v1/parser/FateParser.g4
index 4859c85..d618513 100644
--- a/src/core/src/tonkadur/fate/v1/parser/FateParser.g4
+++ b/src/core/src/tonkadur/fate/v1/parser/FateParser.g4
@@ -187,7 +187,37 @@ first_level_fate_instr:
          (
             start_origin,
             ($type.result),
-            ($name.result)
+            ($name.result),
+            false
+         );
+
+      WORLD.variables().add(new_variable);
+   }
+
+   | EXTERNAL_KW
+      type
+      WS+
+      name=new_reference_name
+      WS*
+   R_PAREN
+   {
+      final Origin start_origin, type_origin;
+      final Variable new_variable;
+
+      start_origin =
+         CONTEXT.get_origin_at
+         (
+            ($EXTERNAL_KW.getLine()),
+            ($EXTERNAL_KW.getCharPositionInLine())
+         );
+
+      new_variable =
+         new Variable
+         (
+            start_origin,
+            ($type.result),
+            ($name.result),
+            true
          );
 
       WORLD.variables().add(new_variable);
@@ -551,7 +581,8 @@ returns [Instruction result]
          (
             start_origin,
             ($type.result),
-            ($name.result)
+            ($name.result),
+            false
          );
 
       variable_map = LOCAL_VARIABLES.peekFirst();
@@ -1511,7 +1542,8 @@ returns [Instruction result]
                   ($FOR_EACH_KW.getCharPositionInLine())
                ),
                elem_type,
-               ($new_reference_name.result)
+               ($new_reference_name.result),
+               false
             );
 
          variable_map = LOCAL_VARIABLES.peekFirst();
@@ -2027,7 +2059,7 @@ returns [Instruction result]
          );
    }
 
-   | PLAYER_EVENT_KW
+   | (EVENT_KW | PLAYER_EVENT_KW)
       L_PAREN WS* WORD WS* R_PAREN WS+
       {
          HIERARCHICAL_VARIABLES.push(new ArrayList());
@@ -2048,8 +2080,8 @@ returns [Instruction result]
       origin =
          CONTEXT.get_origin_at
          (
-            ($PLAYER_EVENT_KW.getLine()),
-            ($PLAYER_EVENT_KW.getCharPositionInLine())
+            ($L_PAREN.getLine()),
+            ($L_PAREN.getCharPositionInLine())
          );
 
       event = WORLD.input_events().get(origin, ($WORD.text));
@@ -2063,7 +2095,7 @@ returns [Instruction result]
          );
    }
 
-   | PLAYER_EVENT_KW
+   | (EVENT_KW | PLAYER_EVENT_KW)
       L_PAREN WS* WORD WS+ value_list WS* R_PAREN WS+
       {
          HIERARCHICAL_VARIABLES.push(new ArrayList());
@@ -2084,8 +2116,8 @@ returns [Instruction result]
       origin =
          CONTEXT.get_origin_at
          (
-            ($PLAYER_EVENT_KW.getLine()),
-            ($PLAYER_EVENT_KW.getCharPositionInLine())
+            ($L_PAREN.getLine()),
+            ($L_PAREN.getCharPositionInLine())
          );
 
       event = WORLD.input_events().get(origin, ($WORD.text));
@@ -2213,7 +2245,8 @@ returns [Instruction result]
                   ($FOR_EACH_KW.getCharPositionInLine())
                ),
                elem_type,
-               ($new_reference_name.result)
+               ($new_reference_name.result),
+               false
             );
 
          variable_map = LOCAL_VARIABLES.peekFirst();
@@ -2770,7 +2803,8 @@ returns [List<Cons<Variable, Computation>> result]
                   ($L_PAREN.getCharPositionInLine())
                ),
                ($value.result).get_type(),
-               var_name
+               var_name,
+               false
             );
 
          if (variables.containsKey(var_name))
@@ -2863,7 +2897,8 @@ returns [VariableList result]
             (
                origin,
                next_type,
-               ($new_reference_name.result)
+               ($new_reference_name.result),
+               false
             )
          );
       }
diff --git a/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/Compiler.java b/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/Compiler.java
index 79004b2..6319be6 100644
--- a/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/Compiler.java
+++ b/src/core/src/tonkadur/wyrd/v1/compiler/fate/v1/Compiler.java
@@ -90,8 +90,10 @@ public class Compiler
    )
    throws Throwable
    {
+      final List<Instruction> ignored_instr;
       final List<Instruction> init_instr;
 
+      ignored_instr = new ArrayList<Instruction>();
       init_instr = new ArrayList<Instruction>();
 
       for
@@ -104,7 +106,16 @@ public class Compiler
          final Register r;
 
          t = TypeCompiler.compile(this, variable.get_type());
-         r = registers.register(t, variable.get_name(), init_instr);
+
+         if (variable.is_external())
+         {
+            r = registers.register(t, variable.get_name(), ignored_instr);
+         }
+         else
+         {
+            r = registers.register(t, variable.get_name(), init_instr);
+         }
+
          wyrd_world.add_register(r);
       }