org.snapscript.tree.Declaration Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of snap Show documentation
Dynamic scripting for the JVM
The newest version!
package org.snapscript.tree;

import java.util.concurrent.atomic.AtomicReference;

import org.snapscript.core.Evaluation;
import org.snapscript.core.constraint.Constraint;
import org.snapscript.core.error.InternalStateException;
import org.snapscript.core.scope.Scope;
import org.snapscript.core.scope.index.Address;
import org.snapscript.core.scope.index.ScopeIndex;
import org.snapscript.core.scope.index.Local;
import org.snapscript.core.scope.index.ScopeTable;
import org.snapscript.core.variable.Value;
import org.snapscript.tree.literal.TextLiteral;

public class Declaration {

   private final AtomicReference location;
   private final DeclarationAllocator allocator;
   private final NameReference reference;
   private final Evaluation value;
   
   public Declaration(TextLiteral identifier) {
      this(identifier, null, null);
   }
   
   public Declaration(TextLiteral identifier, Constraint constraint) {      
      this(identifier, constraint, null);
   }
   
   public Declaration(TextLiteral identifier, Evaluation value) {
      this(identifier, null, value);
   }
   
   public Declaration(TextLiteral identifier, Constraint constraint, Evaluation value) {
      this.allocator = new DeclarationAllocator(constraint, value);
      this.reference = new NameReference(identifier);
      this.location = new AtomicReference();
      this.value = value;
   }   

   public Address define(Scope scope, int modifiers) throws Exception {
      String name = reference.getName(scope);
      
      if(value != null){
         value.define(scope); // must compile value first
      }
      ScopeIndex index = scope.getIndex();
      Address address = index.index(name);
      
      location.set(address);
      return address;
   }
   
   public Value compile(Scope scope, int modifiers) throws Exception {
      String name = reference.getName(scope);
      Local local = allocator.compile(scope, name, modifiers);
      ScopeTable table = scope.getTable();
      Address address = location.get();
      
      try {
         table.addValue(address, local);
      }catch(Exception e) {
         throw new InternalStateException("Declaration of variable '" + name +"' failed", e);
      }  
      return local;
   }
   
   public Value declare(Scope scope, int modifiers) throws Exception {
      String name = reference.getName(scope);
      Local local = allocator.allocate(scope, name, modifiers);
      ScopeTable table = scope.getTable();
      Address address = location.get();
      
      try {
         table.addValue(address, local);
      }catch(Exception e) {
         throw new InternalStateException("Declaration of variable '" + name +"' failed", e);
      }  
      return local;
   }
}