Add first parts of metamodel for the action language (in dot format, as

it is not easy to draw by hand)

AL.dot

@@ -0,0 +1,59 @@
+digraph G{
+    // Inheritance links between superclasses
+    Expression -> Action [arrowhead="empty"];
+    Statement -> Action [arrowhead="empty"];
+    Action -> Any [arrowhead="empty"];
+
+    // Links on superclasses
+    Statement -> Statement [label="next"];
+
+    // Inheritance hierarchy
+    If -> Statement [arrowhead="empty"];
+    While -> Statement [arrowhead="empty"];
+    Assign -> Statement [arrowhead="empty"];
+    Call -> Statement [arrowhead="empty"];
+    Call -> Expression [arrowhead="empty"];
+    Break -> Statement [arrowhead="empty"];
+    Continue -> Statement [arrowhead="empty"];
+    Return -> Statement [arrowhead="empty"];
+    Resolve -> Statement [arrowhead="empty"];
+    Resolve -> Lvalue [arrowhead="empty"];
+    Access -> Expression [arrowhead="empty"];
+    Constant -> Expression [arrowhead="empty"];
+    Constant -> Lvalue [arrowhead="empty"];
+    Input -> Expression [arrowhead="empty"];
+    Output -> Statement [arrowhead="empty"];
+    Declare -> Statement [arrowhead="empty"];
+    Global -> Statement [arrowhead="empty"];
+
+    // Actual types
+    // If
+    If -> Expression [label="cond"];
+    If -> Statement [label="true"];
+    If -> Statement [label="false"];
+
+    // While
+    While -> Expression [label="cond"];
+    While -> Statement [label="body"];
+
+    // Assign
+    Assign -> Lvalue [label="var"];
+    Assign -> Expression [label="value"];
+
+    // Call
+    Call -> Expression [label="func"];
+    Call -> Param [label="params"];
+    Call -> Param [label="last_param"];
+
+    // Break
+    Break -> While [label="while"];
+    
+    // Continue
+    Continue -> While [label="while"];
+
+    // Return
+    Return -> Expression [label="value"];
+
+    // Resolve
+    Resolve -> Any [label="var"];
+}