ExprFactory.java

/*
 * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Resin Open Source is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *
 *   Free Software Foundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package com.caucho.quercus.expr;

import com.caucho.quercus.Location;
import com.caucho.quercus.Quercus;
import com.caucho.quercus.env.*;
import com.caucho.quercus.parser.QuercusParser;
import com.caucho.quercus.program.*;
import com.caucho.quercus.statement.*;
import com.caucho.vfs.Path;

import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.io.UnsupportedEncodingException;

/**
 * Factory for creating PHP expressions and statements
 */
public class ExprFactory {
  private static final Logger log
    = Logger.getLogger(ExprFactory.class.getName());

  public ExprFactory()
  {
  }

  public static ExprFactory create()
  {
    try {
      Class cl = Class.forName("com.caucho.quercus.expr.ProExprFactory");

      return (ExprFactory) cl.newInstance();
    } catch (Exception e) {
      log.log(Level.FINEST, e.toString(), e);

      return new ExprFactory();
    }
  }

  /**
   * Creates a null literal expression.
   */
  public Expr createNull()
  {
    return NullLiteralExpr.NULL;
  }

  /**
   * Creates a string (php5) literal expression.
   */
  public Expr createString(String lexeme, String encoding)
  {
    byte[] buffer = null;
    try {
      buffer = lexeme.getBytes(encoding);
    } catch (UnsupportedEncodingException e) {
      buffer = new byte[lexeme.length()];
      for (int i = 0; i < buffer.length; ++i) {
        buffer[i] = (byte)lexeme.charAt(i);
      }
    }
    return new StringLiteralExpr(new StringBuilderValue(buffer));
  }

  public Expr createString(StringValue lexeme)
  {
    return new StringLiteralExpr(lexeme);
  }

  /**
   * Creates a string literal expression.
   */
  public Expr createUnicode(String lexeme)
  {
    return new UnicodeLiteralExpr(lexeme);
  }

  /**
   * Creates a binary literal expression.
   */
  public Expr createBinary(byte []bytes)
  {
    return new BinaryLiteralExpr(bytes);
  }

  /**
   * Creates a binary literal expression.
   */
  public Expr createBinary(String bytes, String encoding)
  {
    return new BinaryLiteralExpr(bytes, encoding);
  }

  /**
   * Creates a long literal expression.
   */
  public Expr createLong(long value)
  {
    return new LongLiteralExpr(value);
  }

  /**
   * Creates a string literal expression.
   */
  public Expr createLiteral(Value literal)
  {
    return new LiteralExpr(literal);
  }

  /**
   * Creates a var expression.
   */
  public VarExpr createVar(VarInfo var)
  {
    return new VarExpr(var);
  }

  /**
   * Creates a var expression.
   */
  public VarVarExpr createVarVar(Expr var)
  {
    return new VarVarExpr(var);
  }

  /**
   * Creates a const expression.
   */
  public ConstExpr createConst(String name)
  {
    return new ConstExpr(name);
  }

  /**
   * Creates a class const expression.
   */
  public ClassConstExpr createClassConst(String className, String name)
  {
    return new ClassConstExpr(className, name);
  }
  
  /**
   * Creates a class const expression (static::FOO).
   */
  public LateStaticBindingClassConstExpr
    createLateStaticBindingClassConst(String name)
  {
    return new LateStaticBindingClassConstExpr(name);
  }

  /**
   * Creates a this expression.
   */
  public ThisExpr createThis(Location location, InterpretedClassDef cl)
  {
    return new ThisExpr(location, cl);
  }

  /**
   * Creates an array get 'a[0]' expression.
   * @param location
   */
  public ArrayGetExpr createArrayGet(Location location,
                                     Expr base,
                                     Expr index)
  {
    if (base instanceof ArrayGetExpr
        || base instanceof FieldGetExpr
        || base instanceof FieldVarGetExpr)
      return new ArrayGetGetExpr(location, base, index);
    else
      return new ArrayGetExpr(location, base, index);
  }

  /**
   * Creates an array tail 'a[]' expression.
   * @param location TODO
   */
  public ArrayTailExpr createArrayTail(Location location, Expr base)
  {
    return new ArrayTailExpr(location, base);
  }

  /**
   * Creates an object get '$a->b' expression.
   */
  public Expr createFieldGet(Location location,
                             Expr base,
                             StringValue name)
  {
    return new FieldGetExpr(location, base, name);
  }

  /**
   * Creates an object get '$a->$b' expression.
   */
  public Expr createFieldVarGet(Location location,
                                Expr base,
                                Expr name)
  {
    return new FieldVarGetExpr(location, base, name);
  }

  /**
   * Creates an object get 'a::b' expression.
   */
  public Expr createStaticFieldGet(Location location,
                                   String className,
                                   String name)
  {
    return new StaticFieldGetExpr(location, className, name);
  }
  
  /**
   * Creates an object get 'static::b' expression.
   */
  public Expr createLateStaticBindingFieldGet(Location location,
                                              String name)
  {
    return new LateStaticBindingFieldGetExpr(location, name);
  }

  /**
   * Creates an object get 'a::${b}' expression.
   */
  public Expr createStaticFieldVarGet(Location location,
                                      String className,
                                      Expr name)
  {
    return new StaticFieldVarGetExpr(location, className, name);
  }
  
  /**
   * Creates an object get 'static::${b}' expression.
   */
  public Expr createLateStaticBindingFieldVarGet(Location location,
                                                 Expr name)
  {
    return new LateStaticBindingFieldVarGetExpr(location, name);
  }
  
  /**
   * Creates an unset '$a' expression.
   */
  public Expr createUnsetVar(AbstractVarExpr var)
  {
    return new UnsetVarExpr(var);
  }

  /**
   * Creates a char at 'a{0}' expression.
   */
  public CharAtExpr createCharAt(Expr base, Expr index)
  {
    return new CharAtExpr(base, index);
  }

  /**
   * Creates a post increment 'a++' expression.
   */
  public PostIncrementExpr createPostIncrement(Expr expr, int incr)
  {
    return new PostIncrementExpr(expr, incr);
  }

  /**
   * Creates a pre increment '++a' expression.
   */
  public PreIncrementExpr createPreIncrement(Expr expr, int incr)
  {
    return new PreIncrementExpr(expr, incr);
  }

  /**
   * Creates a unary minus '-a' expression.
   */
  public Expr createMinus(Expr expr)
  {
    return new MinusExpr(expr);
  }

  /**
   * Creates a unary plus '+a' expression.
   */
  public Expr createPlus(Expr expr)
  {
    return new PlusExpr(expr);
  }

  /**
   * Creates a unary not '!a' expression.
   */
  public Expr createNot(Expr expr)
  {
    return new NotExpr(expr);
  }

  /**
   * Creates a unary inversion '~a' expression.
   */
  public Expr createBitNot(Expr expr)
  {
    return new BitNotExpr(expr);
  }

  /**
   * Creates a clone 'clone a' expression.
   */
  public Expr createClone(Expr expr)
  {
    return new CloneExpr(expr);
  }

  /**
   * Creates a clone 'clone a' expression.
   */
  public Expr createCopy(Expr expr)
  {
    return new CopyExpr(expr);
  }

  /**
   * Creates an error suppression '@a' expression.
   */
  public Expr createSuppress(Expr expr)
  {
    return new SuppressErrorExpr(expr);
  }

  /**
   * Creates a boolean cast
   */
  public Expr createToBoolean(Expr expr)
  {
    return new ToBooleanExpr(expr);
  }

  /**
   * Creates a long cast
   */
  public Expr createToLong(Expr expr)
  {
    return new ToLongExpr(expr);
  }

  /**
   * Creates a double cast
   */
  public Expr createToDouble(Expr expr)
  {
    return new ToDoubleExpr(expr);
  }

  /**
   * Creates a string cast
   */
  public Expr createToString(Expr expr)
  {
    return new ToStringExpr(expr);
  }

  /**
   * Creates a unicode cast
   */
  public Expr createToUnicode(Expr expr)
  {
    return new ToUnicodeExpr(expr);
  }

  /**
   * Creates a binary string cast
   */
  public Expr createToBinary(Expr expr)
  {
    return new ToBinaryExpr(expr);
  }

  /**
   * Creates an object cast
   */
  public Expr createToObject(Expr expr)
  {
    return new ToObjectExpr(expr);
  }

  /**
   * Creates an array cast
   */
  public Expr createToArray(Expr expr)
  {
    return new ToArrayExpr(expr);
  }

  /**
   * Creates a die 'die("msg")' expression.
   */
  public Expr createDie(Expr expr)
  {
    return new DieExpr(expr);
  }

  /**
   * Creates an exit 'exit("msg")' expression.
   */
  public Expr createExit(Expr expr)
  {
    return new ExitExpr(expr);
  }

  /**
   * Creates a required
   */
  public Expr createRequired()
  {
    return RequiredExpr.REQUIRED;
  }

  /**
   * Creates a default
   */
  public Expr createDefault()
  {
    return new DefaultExpr();
  }

  /**
   * Creates an addition expression.
   */
  public Expr createAdd(Expr left, Expr right)
  {
    return new AddExpr(left, right);
  }

  /**
   * Creates a subtraction expression.
   */
  public Expr createSub(Expr left, Expr right)
  {
    return new SubExpr(left, right);
  }

  /**
   * Creates a multiplication expression.
   */
  public Expr createMul(Expr left, Expr right)
  {
    return new MulExpr(left, right);
  }

  /**
   * Creates a division expression.
   */
  public Expr createDiv(Expr left, Expr right)
  {
    return new DivExpr(left, right);
  }

  /**
   * Creates a modulo expression.
   */
  public Expr createMod(Expr left, Expr right)
  {
    return new ModExpr(left, right);
  }

  /**
   * Creates a left-shift expression.
   */
  public Expr createLeftShift(Expr left, Expr right)
  {
    return new LeftShiftExpr(left, right);
  }

  /**
   * Creates a right-shift expression.
   */
  public Expr createRightShift(Expr left, Expr right)
  {
    return new RightShiftExpr(left, right);
  }

  /**
   * Creates a bit-and expression.
   */
  public Expr createBitAnd(Expr left, Expr right)
  {
    return new BitAndExpr(left, right);
  }

  /**
   * Creates a bit-or expression.
   */
  public Expr createBitOr(Expr left, Expr right)
  {
    return new BitOrExpr(left, right);
  }

  /**
   * Creates a bit-xor expression.
   */
  public Expr createBitXor(Expr left, Expr right)
  {
    return new BitXorExpr(left, right);
  }

  /**
   * Creates an append expression
   */
  public final Expr createAppend(Expr left, Expr right)
  {
    AppendExpr leftAppend;

    // XXX: i18n binary vs unicode issues
    /*
    if (left instanceof ToStringExpr)
      left = ((ToStringExpr) left).getExpr();

    if (left instanceof StringLiteralExpr) {
      StringLiteralExpr string = (StringLiteralExpr) left;

      if (string.evalConstant().length() == 0)
        return ToStringExpr.create(right);
    }
    */

    if (left instanceof AppendExpr)
      leftAppend = (AppendExpr) left;
    else
      leftAppend = createAppendImpl(left, null);
    
    AppendExpr next;

    /*
    if (right instanceof ToStringExpr)
      right = ((ToStringExpr) right).getExpr();

    if (right instanceof StringLiteralExpr) {
      StringLiteralExpr string = (StringLiteralExpr) right;

      if (string.evalConstant().length() == 0)
        return ToStringExpr.create(left);
    }
    */

    if (right instanceof AppendExpr)
      next = (AppendExpr) right;
    else
      next = createAppendImpl(right, null);

    AppendExpr result = append(leftAppend, next);

    if (result.getNext() != null)
      return result;
    else
      return result.getValue();
  }

  /**
   * Appends the tail to the current expression, combining
   * constant literals.
   */
  private AppendExpr append(AppendExpr left, AppendExpr tail)
  {
    if (left == null)
      return tail;
    
    tail = append(left.getNext(), tail);
    
    if (left.getValue() instanceof BinaryLiteralExpr
        && tail.getValue() instanceof BinaryLiteralExpr) {
      BinaryLiteralExpr leftString = (BinaryLiteralExpr) left.getValue();
      BinaryLiteralExpr rightString = (BinaryLiteralExpr) tail.getValue();

      try {
        byte []bytes = (leftString.evalConstant().toString()
            + rightString.evalConstant().toString()).getBytes("ISO-8859-1");

        Expr value = createBinary(bytes);

        return createAppendImpl(value, tail.getNext());
      } catch (java.io.UnsupportedEncodingException e) {
        throw new RuntimeException(e);
      }
    }
    else if (left.getValue() instanceof BinaryLiteralExpr
             || tail.getValue() instanceof BinaryLiteralExpr) {
      left.setNext(tail);

      return left;
    }
    else if (left.getValue() instanceof StringLiteralExpr
             && tail.getValue() instanceof StringLiteralExpr) {
      StringLiteralExpr leftString = (StringLiteralExpr) left.getValue();
      StringLiteralExpr rightString = (StringLiteralExpr) tail.getValue();

      Expr value = createString(new StringBuilderValue()
                                .append(leftString.evalConstant())
                                .append(rightString.evalConstant()));

      return createAppendImpl(value, tail.getNext());
    }
    else if (left.getValue() instanceof UnicodeLiteralExpr
             && tail.getValue() instanceof UnicodeLiteralExpr) {
      UnicodeLiteralExpr leftString = (UnicodeLiteralExpr) left.getValue();
      UnicodeLiteralExpr rightString = (UnicodeLiteralExpr) tail.getValue();

      Expr value = createUnicode(leftString.evalConstant().toString()
                                 + rightString.evalConstant().toString());

      return createAppendImpl(value, tail.getNext());
    }
    else {
      left.setNext(tail);

      return left;
    }
  }
  
  protected AppendExpr createAppendImpl(Expr left, AppendExpr right)
  {
    return new AppendExpr(left, right);
  }

  /**
   * Creates a lt expression.
   */
  public Expr createLt(Expr left, Expr right)
  {
    return new LtExpr(left, right);
  }

  /**
   * Creates a leq expression.
   */
  public Expr createLeq(Expr left, Expr right)
  {
    return new LeqExpr(left, right);
  }

  /**
   * Creates a gt expression.
   */
  public Expr createGt(Expr left, Expr right)
  {
    return new GtExpr(left, right);
  }

  /**
   * Creates a geq expression.
   */
  public Expr createGeq(Expr left, Expr right)
  {
    return new GeqExpr(left, right);
  }

  /**
   * Creates an eq expression.
   */
  public Expr createEq(Expr left, Expr right)
  {
    return new EqExpr(left, right);
  }

  /**
   * Creates a neq expression.
   */
  public Expr createNeq(Expr left, Expr right)
  {
    return new NeqExpr(left, right);
  }

  /**
   * Creates an equals expression.
   */
  public Expr createEquals(Expr left, Expr right)
  {
    return new EqualsExpr(left, right);
  }

  /**
   * Creates an assignment expression.
   */
  public Expr createAssign(AbstractVarExpr left, Expr right)
  {
    return new AssignExpr(left, right);
  }

  /**
   * Creates an assignment expression.
   */
  public Expr createAssignRef(AbstractVarExpr left, Expr right)
  {
    return new AssignRefExpr(left, right);
  }

  /**
   * Creates a ref '&$a' expression.
   */
  public RefExpr createRef(Expr base)
  {
    return new RefExpr(base);
  }

  /**
   * Creates an and expression.
   */
  public Expr createAnd(Expr left, Expr right)
  {
    return new AndExpr(left, right);
  }

  /**
   * Creates an or expression.
   */
  public Expr createOr(Expr left, Expr right)
  {
    return new OrExpr(left, right);
  }

  /**
   * Creates an xor expression.
   */
  public Expr createXor(Expr left, Expr right)
  {
    return new XorExpr(left, right);
  }

  /**
   * Creates a comma expression.
   */
  public Expr createComma(Expr left, Expr right)
  {
    return new CommaExpr(left, right);
  }

  /**
   * Creates an instanceof expression.
   */
  public Expr createInstanceOf(Expr expr, String name)
  {
    return new InstanceOfExpr(expr, name);
  }

  /**
   * Creates an instanceof expression.
   */
  public Expr createInstanceOfVar(Expr expr, Expr name)
  {
    return new InstanceOfVarExpr(expr, name);
  }

  /**
   * Creates an each expression.
   */
  public Expr createEach(Expr expr)
  {
    return new EachExpr(expr);
  }

  /**
   * Creates a list expression.
   */
  public final Expr createList(QuercusParser parser,
                               ListHeadExpr head, Expr value)
  {
    boolean isSuppress = value instanceof SuppressErrorExpr;

    if (isSuppress) {
      SuppressErrorExpr suppressExpr = (SuppressErrorExpr) value;

      value = suppressExpr.getExpr();
    }

    Expr expr;

    if (value instanceof EachExpr) {
      expr = createListEach(head.getVarList(), (EachExpr) value);
    }
    else
      expr = createList(head, value);

    if (isSuppress)
      return createSuppress(expr);
    else
      return expr;
  }

  /**
   * Creates a list expression.
   */
  public ListHeadExpr createListHead(ArrayList<Expr> keys)
  {
    return new ListHeadExpr(keys);
  }

  /**
   * Creates a list expression.
   */
  public Expr createList(ListHeadExpr head, Expr value)
  {
    return new ListExpr(head, value);
  }

  /**
   * Creates a list expression.
   */
  public Expr createListEach(Expr []varList, EachExpr value)
  {
    return new ListEachExpr(varList, value);
  }

  /**
   * Creates an conditional expression.
   */
  public Expr createConditional(Expr test, Expr left, Expr right)
  {
    return new ConditionalExpr(test, left, right);
  }

  /**
   * Creates a array() expression.
   */
  public Expr createArrayFun(ArrayList<Expr> keys, ArrayList<Expr> values)
  {
    return new ArrayFunExpr(keys, values);
  }

  /**
   * Creates a new function call.
   */
  public Expr createFunction(Location loc,
                             String name,
                             ArrayList<Expr> args)
  {
    return new FunctionExpr(loc, name, args);
  }

  /**
   * Creates a new var function call.
   */
  public VarFunctionExpr createVarFunction(Location loc,
                                           Expr name,
                                           ArrayList<Expr> args)
  {
    return new VarFunctionExpr(loc, name, args);
  }

  /**
   * Creates a new function call.
   */
  public Expr createClassMethod(Location loc,
                                String className,
                                String name,
                                ArrayList<Expr> args)
  {
    return new ClassMethodExpr(loc, className, name, args);
  }
  
  /**
   * Creates a new function call based on the class context.
   */
  public Expr createLateStaticBindingClassMethod(Location loc,
                                                 String name,
                                                 ArrayList<Expr> args)
  {
    return new LateStaticBindingClassMethodExpr(loc, name, args);
  }

  /**
   * Creates a static function call.
   */
  public Expr createStaticMethod(Location loc,
                                 String className,
                                 String name,
                                 ArrayList<Expr> args)
  {
    return new StaticMethodExpr(loc, className, name, args);
  }
  
  /**
   * Creates a static function call based on the calling class.
   */
  public Expr createLateStaticBindingStaticMethod(Location loc,
                                                  String name,
                                                  ArrayList<Expr> args)
  {
    return new LateStaticBindingStaticMethodExpr(loc, name, args);
  }

  /**
   * Creates a new method A::$f()
   */
  public Expr createStaticVarMethod(Location loc,
                                    String className,
                                    Expr var,
                                    ArrayList<Expr> args)
  {
    return new StaticVarMethodExpr(loc, className, var, args);
  }
  
  /**
   * Creates a new method static::$f()
   */
  public Expr createLateStaticBindingStaticVarMethod(Location loc,
                                                     Expr var,
                                                     ArrayList<Expr> args)
  {
    return new LateStaticBindingStaticVarMethodExpr(loc, var, args);
  }

  /**
   * Creates a new method call.
   */
  public Expr createMethodCall(Location loc,
                                       Expr objExpr,
                                       String name,
                                       ArrayList<Expr> args)
  {
    return new MethodCallExpr(loc, objExpr, name, args);
  }

  /**
   * Creates a new method call.
   */
  public Expr createVarMethodCall(Location loc,
                                  Expr objExpr,
                                  Expr name,
                                  ArrayList<Expr> args)
  {
    return new VarMethodCallExpr(loc, objExpr, name, args);
  }

  /**
   * Creates a new function call.
   */
  public NewExpr createNew(Location loc,
                           String name,
                           ArrayList<Expr> args)
  {
    return new NewExpr(loc, name, args);
  }

  /**
   * Creates a new function call.
   */
  public VarNewExpr createVarNew(Location loc,
                                 Expr name,
                                 ArrayList<Expr> args)
  {
    return new VarNewExpr(loc, name, args);
  }

  /**
   * Creates an include expr
   */
  public Expr createInclude(Location loc,
                            Path source,
                            Expr expr)
  {
    return new IncludeExpr(loc, source, expr, false);
  }

  /**
   * Creates an include expr
   */
  public Expr createRequire(Location loc,
                            Path source,
                            Expr expr)
  {
    return new IncludeExpr(loc, source, expr, true);
  }

  /**
   * Creates an include expr
   */
  public Expr createIncludeOnce(Location loc,
                                Path source,
                                Expr expr)
  {
    return new IncludeOnceExpr(loc, source, expr, false);
  }

  /**
   * Creates an include expr
   */
  public Expr createRequireOnce(Location loc,
                                Path source,
                                Expr expr)
  {
    return new IncludeOnceExpr(loc, source, expr, true);
  }

  /**
   * Creates a Quercus class import.
   */
  public Expr createImport(Location loc,
                           String name,
                           boolean isWildcard)
  {
    return new ImportExpr(loc, name, isWildcard);
  }

  /**
   * Creates a null literal expression.
   */
  public Statement createNullStatement()
  {
    return NullStatement.NULL;
  }

  /**
   * Creates an echo statement
   */
  public Statement createEcho(Location loc, Expr expr)
  {
    return new EchoStatement(loc, expr);
  }

  /**
   * Creates an expr statement
   */
  public Statement createExpr(Location loc, Expr expr)
  {
    return new ExprStatement(loc, expr);
  }

  public final Statement createBlock(Location loc,
                                     ArrayList<Statement> statementList)
  {
    if (statementList.size() == 1)
      return statementList.get(0);

    Statement []statements = new Statement[statementList.size()];

    statementList.toArray(statements);

    return createBlockImpl(loc, statements);
  }

  public final Statement createBlock(Location loc, Statement []statementList)
  {
    if (statementList.length == 1)
      return statementList[0];

    Statement []statements = new Statement[statementList.length];

    System.arraycopy(statementList, 0, statements, 0, statementList.length);

    return createBlockImpl(loc, statements);
  }

  /**
   * Creates an expr statement
   */
  public final BlockStatement createBlockImpl(Location loc,
                                              ArrayList<Statement> statementList)
  {
    Statement []statements = new Statement[statementList.size()];

    statementList.toArray(statements);
    
    return createBlockImpl(loc, statements);
  }

  /**
   * Creates an expr statement
   */
  public BlockStatement createBlockImpl(Location loc, Statement []statements)
  {
    return new BlockStatement(loc, statements);
  }

  /**
   * Creates a text statement
   */
  public Statement createText(Location loc, StringValue text)
  {
    return new TextStatement(loc, text);
  }

  /**
   * Creates a text statement
   */
  public Statement createText(Location loc, String text, String encoding)
  {
    byte[] buffer = null;
    try {
      buffer = text.getBytes(encoding);
    } catch (UnsupportedEncodingException e) {
      buffer = new byte[text.length()];
      for (int i = 0; i < buffer.length; ++i) {
        buffer[i] = (byte)text.charAt(i);
      }
    }
    return createText(loc, new StringBuilderValue(buffer));
  }

  /**
   * Creates an if statement
   */
  public Statement createIf(Location loc,
                            Expr test,
                            Statement trueBlock,
                            Statement falseBlock)
  {
    return new IfStatement(loc, test, trueBlock, falseBlock);
  }

  /**
   * Creates a switch statement
   */
  public Statement createSwitch(Location loc,
                                Expr value,
                                ArrayList<Expr[]> caseList,
                                ArrayList<BlockStatement> blockList,
                                Statement defaultBlock,
                                String label)
  {
    return new SwitchStatement(loc, value, caseList, blockList,
                               defaultBlock, label);
  }

  /**
   * Creates a for statement
   */
  public Statement createFor(Location loc,
                             Expr init,
                             Expr test,
                             Expr incr,
                             Statement block,
                             String label)
  {
    return new ForStatement(loc, init, test, incr, block, label);
  }

  /**
   * Creates a foreach statement
   */
  public Statement createForeach(Location loc,
                                 Expr objExpr,
                                 AbstractVarExpr key,
                                 AbstractVarExpr value,
                                 boolean isRef,
                                 Statement block,
                                 String label)
  {
    return new ForeachStatement(loc, objExpr, key, value, isRef,
                                block, label);
  }

  /**
   * Creates a while statement
   */
  public Statement createWhile(Location loc,
                               Expr test,
                               Statement block,
                               String label)
  {
    return new WhileStatement(loc, test, block, label);
  }

  /**
   * Creates a do-while statement
   */
  public Statement createDo(Location loc,
                            Expr test,
                            Statement block,
                            String label)
  {
    return new DoStatement(loc, test, block, label);
  }

  /**
   * Creates a break statement
   */
  public BreakStatement createBreak(Location location,
                                    Expr target,
                                    ArrayList<String> loopLabelList)
  {
    return new BreakStatement(location, target, loopLabelList);
  }

  /**
   * Creates a continue statement
   */
  public ContinueStatement createContinue(Location location,
                                          Expr target,
                                          ArrayList<String> loopLabelList)
  {
    return new ContinueStatement(location, target, loopLabelList);
  }

  /**
   * Creates a global statement
   */
  public Statement createGlobal(Location loc,
                                VarExpr var)
  {
    return new GlobalStatement(loc, var);
  }

  /**
   * Creates a global var statement
   */
  public Statement createVarGlobal(Location loc,
                                   VarVarExpr var)
  {
    return new VarGlobalStatement(loc, var);
  }

  /**
   * Creates a static statement
   */
  public Statement createStatic(Location loc,
                                VarExpr var,
                                Expr value)
  {
    return new StaticStatement(loc, var, value);
  }

  /**
   * Creates a throw statement
   */
  public Statement createThrow(Location loc,
                                Expr value)
  {
    return new ThrowStatement(loc, value);
  }

  /**
   * Creates a try statement
   */
  public TryStatement createTry(Location loc,
                                Statement block)
  {
    return new TryStatement(loc, block);
  }

  /**
   * Creates a return statement
   */
  public Statement createReturn(Location loc,
                                Expr value)
  {
    return new ReturnStatement(loc, value);
  }

  /**
   * Creates a return ref statement
   */
  public Statement createReturnRef(Location loc,
                                   Expr value)
  {
    return new ReturnRefStatement(loc, value);
  }

  /**
   * Creates a new function definition def.
   */
  public Statement createFunctionDef(Location loc,
                                     Function fun)
  {
    return new FunctionDefStatement(loc, fun);
  }

  /**
   * Creates a new function def statement
   */
  public Statement createClassDef(Location loc,
                                  InterpretedClassDef cl)
  {
    return new ClassDefStatement(loc, cl);
  }

  //
  // functions
  //
  
  /**
   * Creates a new FunctionInfo
   */
  public FunctionInfo createFunctionInfo(Quercus quercus, String name)
  {
    return new FunctionInfo(quercus, name);
  }
  
  /**
   * Creates a new function definition.
   */
  public Function createFunction(Location loc,
                                 String name,
                                 FunctionInfo info,
                                 Arg []argList,
                                 Statement []statementList)
  {
    return new Function(this, loc, name, info, argList, statementList);
  }

  /**
   * Creates a new object method definition.
   */
  public Function createObjectMethod(Location loc,
                                     InterpretedClassDef cl,
                                     String name,
                                     FunctionInfo info,
                                     Arg []argList,
                                     Statement []statementList)
  {
    return new ObjectMethod(this, loc, cl, name, info, argList, statementList);
  }

  /**
   * Creates a new object method definition.
   */
  public Function createMethodDeclaration(Location loc,
                                          InterpretedClassDef cl,
                                          String name,
                                          FunctionInfo info,
                                          Arg []argList)
  {
    return new MethodDeclaration(this, loc, cl, name, info, argList);
  }

  public InterpretedClassDef createClassDef(Location location,
                                            String name,
                                            String parentName,
                                            String[] ifaceList,
                                            int index)
  {
    return new InterpretedClassDef(location,
                                   name, parentName, ifaceList,
                                   index);
  }
}