refactor support for working with Value instances

git-svn-id: https://svn.code.sf.net/p/jackcess/code/jackcess/trunk@1192 f203690c-595d-4dc9-a70b-905162fa7fd2

src/main/java/com/healthmarketscience/jackcess/impl/BaseEvalContext.java

@@ -33,8 +33,8 @@ import com.healthmarketscience.jackcess.expr.Expression;
 import com.healthmarketscience.jackcess.expr.Identifier;
 import com.healthmarketscience.jackcess.expr.TemporalConfig;
 import com.healthmarketscience.jackcess.expr.Value;
-import com.healthmarketscience.jackcess.impl.expr.BuiltinOperators;
 import com.healthmarketscience.jackcess.impl.expr.Expressionator;
+import com.healthmarketscience.jackcess.impl.expr.ValueSupport;
 
 /**
  *
@@ -132,28 +132,28 @@ public abstract class BaseEvalContext implements EvalContext
     try {
       val = ColumnImpl.toInternalValue(dType, val, getDatabase());
       if(val == null) {
-        return BuiltinOperators.NULL_VAL;
+        return ValueSupport.NULL_VAL;
       }
 
       Value.Type vType = toValueType(dType);
       switch(vType) {
       case STRING:
-        return BuiltinOperators.toValue(val.toString());
+        return ValueSupport.toValue(val.toString());
       case DATE:
       case TIME:
       case DATE_TIME:
-        return BuiltinOperators.toValue(this, vType, (Date)val);
+        return ValueSupport.toValue(this, vType, (Date)val);
       case LONG:
         Integer i = ((val instanceof Integer) ? (Integer)val :
                      ((Number)val).intValue());
-        return BuiltinOperators.toValue(i);
+        return ValueSupport.toValue(i);
       case DOUBLE:
         Double d = ((val instanceof Double) ? (Double)val :
                     ((Number)val).doubleValue());
-        return BuiltinOperators.toValue(d);
+        return ValueSupport.toValue(d);
       case BIG_DEC:
         BigDecimal bd = ColumnImpl.toBigDecimal(val, getDatabase());
-        return BuiltinOperators.toValue(bd);
+        return ValueSupport.toValue(bd);
       default:
         throw new RuntimeException("Unexpected type " + vType);
       }

src/main/java/com/healthmarketscience/jackcess/impl/expr/BuiltinOperators.java

@@ -17,15 +17,13 @@ limitations under the License.
 package com.healthmarketscience.jackcess.impl.expr;
 
 import java.math.BigDecimal;
-import java.text.DateFormat;
-import java.util.Date;
 import java.util.regex.Pattern;
 
 import com.healthmarketscience.jackcess.expr.EvalContext;
 import com.healthmarketscience.jackcess.expr.EvalException;
 import com.healthmarketscience.jackcess.expr.Value;
-import com.healthmarketscience.jackcess.impl.ColumnImpl;
 import com.healthmarketscience.jackcess.impl.NumberFormatter;
+import static com.healthmarketscience.jackcess.impl.expr.ValueSupport.*;
 
 
 /**
@@ -39,27 +37,6 @@ public class BuiltinOperators
   private static final double MIN_INT = Integer.MIN_VALUE;
   private static final double MAX_INT = Integer.MAX_VALUE;
 
-  public static final Value NULL_VAL = new BaseValue() {
-    @Override public boolean isNull() {
-      return true;
-    }
-    public Type getType() {
-      return Type.NULL;
-    }
-    public Object get() {
-      return null;
-    }
-  };
-  // access seems to like -1 for true and 0 for false (boolean values are
-  // basically an illusion)
-  public static final Value TRUE_VAL = new LongValue(-1);
-  public static final Value FALSE_VAL = new LongValue(0);
-  public static final Value EMPTY_STR_VAL = new StringValue("");
-  public static final Value ZERO_VAL = FALSE_VAL;
-  public static final Value NEG_ONE_VAL = TRUE_VAL;
-  public static final Value ONE_VAL = new LongValue(1);
-
-
   private enum CoercionType {
     SIMPLE(true, true), GENERAL(false, true), COMPARE(false, false);
 
@@ -578,95 +555,6 @@ public class BuiltinOperators
     }
   }
 
-  public static Value toValue(boolean b) {
-    return (b ? TRUE_VAL : FALSE_VAL);
-  }
-
-  public static Value toValue(String s) {
-    return new StringValue(s);
-  }
-
-  public static Value toValue(int i) {
-    return new LongValue(i);
-  }
-
-  public static Value toValue(Integer i) {
-    return new LongValue(i);
-  }
-
-  public static Value toValue(float f) {
-    return new DoubleValue((double)f);
-  }
-
-  public static Value toValue(double s) {
-    return new DoubleValue(s);
-  }
-
-  public static Value toValue(Double s) {
-    return new DoubleValue(s);
-  }
-
-  public static Value toValue(BigDecimal s) {
-    return new BigDecimalValue(normalize(s));
-  }
-
-  public static Value toValue(Value.Type type, double dd, DateFormat fmt) {
-    return toValue(type, new Date(ColumnImpl.fromDateDouble(
-                                      dd, fmt.getCalendar())), fmt);
-  }
-
-  public static Value toValue(EvalContext ctx, Value.Type type, Date d) {
-    return toValue(type, d, getDateFormatForType(ctx, type));
-  }
-
-  public static Value toValue(Value.Type type, Date d, DateFormat fmt) {
-    switch(type) {
-    case DATE:
-      return new DateValue(d, fmt);
-    case TIME:
-      return new TimeValue(d, fmt);
-    case DATE_TIME:
-      return new DateTimeValue(d, fmt);
-    default:
-      throw new EvalException("Unexpected date/time type " + type);
-    }
-  }
-
-  static Value toDateValue(EvalContext ctx, Value.Type type, double v,
-                           Value param1, Value param2)
-  {
-    DateFormat fmt = null;
-    if((param1 instanceof BaseDateValue) && (param1.getType() == type)) {
-      fmt = ((BaseDateValue)param1).getFormat();
-    } else if((param2 instanceof BaseDateValue) && (param2.getType() == type)) {
-      fmt = ((BaseDateValue)param2).getFormat();
-    } else {
-      fmt = getDateFormatForType(ctx, type);
-    }
-
-    Date d = new Date(ColumnImpl.fromDateDouble(v, fmt.getCalendar()));
-
-    return toValue(type, d, fmt);
-  }
-
-  static DateFormat getDateFormatForType(EvalContext ctx, Value.Type type) {
-      String fmtStr = null;
-      switch(type) {
-      case DATE:
-        fmtStr = ctx.getTemporalConfig().getDefaultDateFormat();
-        break;
-      case TIME:
-        fmtStr = ctx.getTemporalConfig().getDefaultTimeFormat();
-        break;
-      case DATE_TIME:
-        fmtStr = ctx.getTemporalConfig().getDefaultDateTimeFormat();
-        break;
-      default:
-        throw new EvalException("Unexpected date/time type " + type);
-      }
-      return ctx.createDateFormat(fmtStr);
-  }
-
   private static Value.Type getMathTypePrecedence(
       Value param1, Value param2, CoercionType cType)
   {
@@ -779,22 +667,4 @@ public class BuiltinOperators
     return ((d == id) && (d >= MIN_INT) && (d <= MAX_INT) &&
             !Double.isInfinite(d) && !Double.isNaN(d));
   }
-
-  /**
-   * Converts the given BigDecimal to the minimal scale >= 0;
-   */
-  static BigDecimal normalize(BigDecimal bd) {
-    if(bd.scale() == 0) {
-      return bd;
-    }
-    // handle a bug in the jdk which doesn't strip zero values
-    if(bd.compareTo(BigDecimal.ZERO) == 0) {
-      return BigDecimal.ZERO;
-    }
-    bd = bd.stripTrailingZeros();
-    if(bd.scale() < 0) {
-      bd = bd.setScale(0);
-    }
-    return bd;
-  }
 }

src/main/java/com/healthmarketscience/jackcess/impl/expr/DefaultDateFunctions.java

@@ -56,9 +56,9 @@ public class DefaultDateFunctions
   public static final Function DATE = registerFunc(new Func0("Date") {
     @Override
     protected Value eval0(EvalContext ctx) {
-      DateFormat fmt = BuiltinOperators.getDateFormatForType(ctx, Value.Type.DATE);
+      DateFormat fmt = ValueSupport.getDateFormatForType(ctx, Value.Type.DATE);
       double dd = dateOnly(currentTimeDouble(fmt));
-      return BuiltinOperators.toValue(Value.Type.DATE, dd, fmt);
+      return ValueSupport.toValue(Value.Type.DATE, dd, fmt);
     }
   });
 
@@ -70,8 +70,8 @@ public class DefaultDateFunctions
         return dv;
       }
       double dd = dateOnly(dv.getAsDouble());
-      DateFormat fmt = BuiltinOperators.getDateFormatForType(ctx, Value.Type.DATE);
-      return BuiltinOperators.toValue(Value.Type.DATE, dd, fmt);
+      DateFormat fmt = ValueSupport.getDateFormatForType(ctx, Value.Type.DATE);
+      return ValueSupport.toValue(Value.Type.DATE, dd, fmt);
     }
   });
 
@@ -87,7 +87,7 @@ public class DefaultDateFunctions
         year += ((year <= 29) ? 2000 : 1900);
       }
 
-      DateFormat fmt = BuiltinOperators.getDateFormatForType(ctx, Value.Type.DATE);
+      DateFormat fmt = ValueSupport.getDateFormatForType(ctx, Value.Type.DATE);
       Calendar cal = fmt.getCalendar();
       cal.clear();
 
@@ -96,24 +96,24 @@ public class DefaultDateFunctions
       cal.set(Calendar.MONTH, month - 1);
       cal.set(Calendar.DAY_OF_MONTH, day);
 
-      return BuiltinOperators.toValue(Value.Type.DATE, cal.getTime(), fmt);
+      return ValueSupport.toValue(Value.Type.DATE, cal.getTime(), fmt);
     }
   });
 
   public static final Function NOW = registerFunc(new Func0("Now") {
     @Override
     protected Value eval0(EvalContext ctx) {
-      DateFormat fmt = BuiltinOperators.getDateFormatForType(ctx, Value.Type.DATE_TIME);
-      return BuiltinOperators.toValue(Value.Type.DATE_TIME, new Date(), fmt);
+      DateFormat fmt = ValueSupport.getDateFormatForType(ctx, Value.Type.DATE_TIME);
+      return ValueSupport.toValue(Value.Type.DATE_TIME, new Date(), fmt);
     }
   });
 
   public static final Function TIME = registerFunc(new Func0("Time") {
     @Override
     protected Value eval0(EvalContext ctx) {
-      DateFormat fmt = BuiltinOperators.getDateFormatForType(ctx, Value.Type.TIME);
+      DateFormat fmt = ValueSupport.getDateFormatForType(ctx, Value.Type.TIME);
       double dd = timeOnly(currentTimeDouble(fmt));
-      return BuiltinOperators.toValue(Value.Type.TIME, dd, fmt);
+      return ValueSupport.toValue(Value.Type.TIME, dd, fmt);
     }
   });
 
@@ -125,17 +125,17 @@ public class DefaultDateFunctions
         return dv;
       }
       double dd = timeOnly(dv.getAsDouble());
-      DateFormat fmt = BuiltinOperators.getDateFormatForType(ctx, Value.Type.TIME);
-      return BuiltinOperators.toValue(Value.Type.TIME, dd, fmt);
+      DateFormat fmt = ValueSupport.getDateFormatForType(ctx, Value.Type.TIME);
+      return ValueSupport.toValue(Value.Type.TIME, dd, fmt);
     }
   });
 
   public static final Function TIMER = registerFunc(new Func0("Timer") {
     @Override
     protected Value eval0(EvalContext ctx) {
-      DateFormat fmt = BuiltinOperators.getDateFormatForType(ctx, Value.Type.TIME);
+      DateFormat fmt = ValueSupport.getDateFormatForType(ctx, Value.Type.TIME);
       double dd = timeOnly(currentTimeDouble(fmt)) * DSECONDS_PER_DAY;
-      return BuiltinOperators.toValue(dd);
+      return ValueSupport.toValue(dd);
     }
   });
 
@@ -156,16 +156,16 @@ public class DefaultDateFunctions
         totalSeconds %= SECONDS_PER_DAY;
       }
 
-      DateFormat fmt = BuiltinOperators.getDateFormatForType(ctx, Value.Type.TIME);
+      DateFormat fmt = ValueSupport.getDateFormatForType(ctx, Value.Type.TIME);
       double dd = totalSeconds / DSECONDS_PER_DAY;
-      return BuiltinOperators.toValue(Value.Type.TIME, dd, fmt);
+      return ValueSupport.toValue(Value.Type.TIME, dd, fmt);
     }
   });
 
   public static final Function HOUR = registerFunc(new Func1NullIsNull("Hour") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(
+      return ValueSupport.toValue(
           nonNullToCalendarField(ctx, param1, Calendar.HOUR_OF_DAY));
     }
   });
@@ -173,7 +173,7 @@ public class DefaultDateFunctions
   public static final Function MINUTE = registerFunc(new Func1NullIsNull("Minute") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(
+      return ValueSupport.toValue(
           nonNullToCalendarField(ctx, param1, Calendar.MINUTE));
     }
   });
@@ -181,7 +181,7 @@ public class DefaultDateFunctions
   public static final Function SECOND = registerFunc(new Func1NullIsNull("Second") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(
+      return ValueSupport.toValue(
           nonNullToCalendarField(ctx, param1, Calendar.SECOND));
     }
   });
@@ -189,7 +189,7 @@ public class DefaultDateFunctions
   public static final Function YEAR = registerFunc(new Func1NullIsNull("Year") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(
+      return ValueSupport.toValue(
           nonNullToCalendarField(ctx, param1, Calendar.YEAR));
     }
   });
@@ -198,7 +198,7 @@ public class DefaultDateFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       // convert from 0 based to 1 based value
-      return BuiltinOperators.toValue(
+      return ValueSupport.toValue(
           nonNullToCalendarField(ctx, param1, Calendar.MONTH) + 1);
     }
   });
@@ -206,7 +206,7 @@ public class DefaultDateFunctions
   public static final Function DAY = registerFunc(new Func1NullIsNull("Day") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(
+      return ValueSupport.toValue(
           nonNullToCalendarField(ctx, param1, Calendar.DAY_OF_MONTH));
     }
   });
@@ -234,7 +234,7 @@ public class DefaultDateFunctions
       // back to 1 based to return the result
       day = (((day - 1) - (firstDay - 1) + 7) % 7) + 1;
 
-      return BuiltinOperators.toValue(day);
+      return ValueSupport.toValue(day);
     }
   });
 
@@ -292,14 +292,14 @@ public class DefaultDateFunctions
 
     Value.Type type = (hasDate ? (hasTime ? Value.Type.DATE_TIME : Value.Type.DATE) :
                        Value.Type.TIME);
-    DateFormat fmt = BuiltinOperators.getDateFormatForType(ctx, type);
-    return BuiltinOperators.toValue(type, dd, fmt);
+    DateFormat fmt = ValueSupport.getDateFormatForType(ctx, type);
+    return ValueSupport.toValue(type, dd, fmt);
   }
 
   private static DateFormat getDateValueFormat(EvalContext ctx, Value param) {
     return ((param instanceof BaseDateValue) ?
             ((BaseDateValue)param).getFormat() :
-       BuiltinOperators.getDateFormatForType(ctx, param.getType()));
+       ValueSupport.getDateFormatForType(ctx, param.getType()));
   }
 
   private static double dateOnly(double dd) {

src/main/java/com/healthmarketscience/jackcess/impl/expr/DefaultFinancialFunctions.java

@@ -65,7 +65,7 @@ public class DefaultFinancialFunctions
         result += calculateAnnuityPaymentPeriods(rate, pmt, fv, pmtType);
       }
 
-      return BuiltinOperators.toValue(result);
+      return ValueSupport.toValue(result);
     }
   });
 
@@ -92,7 +92,7 @@ public class DefaultFinancialFunctions
 
       double result = calculateFutureValue(rate, nper, pmt, pmtType);
 
-      return BuiltinOperators.toValue(result);
+      return ValueSupport.toValue(result);
     }
   });
 
@@ -119,7 +119,7 @@ public class DefaultFinancialFunctions
 
       double result = calculatePresentValue(rate, nper, pmt, pmtType);
 
-      return BuiltinOperators.toValue(result);
+      return ValueSupport.toValue(result);
     }
   });
 
@@ -146,7 +146,7 @@ public class DefaultFinancialFunctions
         result += calculateAnnuityPayment(rate, nper, fv, pmtType);
       }
 
-      return BuiltinOperators.toValue(result);
+      return ValueSupport.toValue(result);
     }
   });
 
@@ -177,7 +177,7 @@ public class DefaultFinancialFunctions
 
   //     double result = calculateInterestPayment(pmt, rate, per, pv, pmtType);
 
-  //     return BuiltinOperators.toValue(result);
+  //     return ValueSupport.toValue(result);
   //   }
   // });
 
@@ -209,7 +209,7 @@ public class DefaultFinancialFunctions
   //     double result = pmt - calculateInterestPayment(pmt, rate, per, pv,
   //                                                    pmtType);
 
-  //     return BuiltinOperators.toValue(result);
+  //     return ValueSupport.toValue(result);
   //   }
   // });
 
@@ -255,7 +255,7 @@ public class DefaultFinancialFunctions
   //       cost -= result;
   //     }
 
-  //     return BuiltinOperators.toValue(result);
+  //     return ValueSupport.toValue(result);
   //   }
   // });
 
@@ -269,7 +269,7 @@ public class DefaultFinancialFunctions
 
   //     double result = calculateStraightLineDepreciation(cost, salvage, life);
 
-  //     return BuiltinOperators.toValue(result);
+  //     return ValueSupport.toValue(result);
   //   }
   // });
 
@@ -285,7 +285,7 @@ public class DefaultFinancialFunctions
   //     double result = calculateSumOfYearsDepreciation(
   //         cost, salvage, life, period);
 
-  //     return BuiltinOperators.toValue(result);
+  //     return ValueSupport.toValue(result);
   //   }
   // });
 

src/main/java/com/healthmarketscience/jackcess/impl/expr/DefaultFunctions.java

@@ -69,10 +69,10 @@ public class DefaultFunctions
     protected Value eval1(EvalContext ctx, Value param1) {
       if((param1.getType() == Value.Type.STRING) &&
          (param1.getAsString().length() == 0)) {
-        return BuiltinOperators.ZERO_VAL;
+        return ValueSupport.ZERO_VAL;
       }
       int lv = param1.getAsLongInt();
-      return BuiltinOperators.toValue(Integer.toHexString(lv).toUpperCase());
+      return ValueSupport.toValue(Integer.toHexString(lv).toUpperCase());
     }
   });
 
@@ -89,7 +89,7 @@ public class DefaultFunctions
       Value.Type resultType = ctx.getResultType();
       return (((resultType == null) ||
                (resultType == Value.Type.STRING)) ?
-              BuiltinOperators.EMPTY_STR_VAL : BuiltinOperators.ZERO_VAL);
+              ValueSupport.EMPTY_STR_VAL : ValueSupport.ZERO_VAL);
     }
   });
 
@@ -99,7 +99,7 @@ public class DefaultFunctions
       Value param1 = params[0];
       int idx = param1.getAsLongInt();
       if((idx < 1) || (idx >= params.length)) {
-        return BuiltinOperators.NULL_VAL;
+        return ValueSupport.NULL_VAL;
       }
       return params[idx];
     }
@@ -116,7 +116,7 @@ public class DefaultFunctions
           return params[i + 1];
         }
       }
-      return BuiltinOperators.NULL_VAL;
+      return ValueSupport.NULL_VAL;
     }
   });
 
@@ -125,10 +125,10 @@ public class DefaultFunctions
     protected Value eval1(EvalContext ctx, Value param1) {
       if((param1.getType() == Value.Type.STRING) &&
          (param1.getAsString().length() == 0)) {
-        return BuiltinOperators.ZERO_VAL;
+        return ValueSupport.ZERO_VAL;
       }
       int lv = param1.getAsLongInt();
-      return BuiltinOperators.toValue(Integer.toOctalString(lv));
+      return ValueSupport.toValue(Integer.toOctalString(lv));
     }
   });
 
@@ -136,7 +136,7 @@ public class DefaultFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       boolean b = param1.getAsBoolean();
-      return BuiltinOperators.toValue(b);
+      return ValueSupport.toValue(b);
     }
   });
 
@@ -147,7 +147,7 @@ public class DefaultFunctions
       if((lv < 0) || (lv > 255)) {
         throw new EvalException("Byte code '" + lv + "' out of range ");
       }
-      return BuiltinOperators.toValue(lv);
+      return ValueSupport.toValue(lv);
     }
   });
 
@@ -156,7 +156,7 @@ public class DefaultFunctions
     protected Value eval1(EvalContext ctx, Value param1) {
       BigDecimal bd = param1.getAsBigDecimal();
       bd = bd.setScale(4, NumberFormatter.ROUND_MODE);
-      return BuiltinOperators.toValue(bd);
+      return ValueSupport.toValue(bd);
     }
   });
 
@@ -174,7 +174,7 @@ public class DefaultFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       Double dv = param1.getAsDouble();
-      return BuiltinOperators.toValue(dv);
+      return ValueSupport.toValue(dv);
     }
   });
 
@@ -182,7 +182,7 @@ public class DefaultFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       BigDecimal bd = param1.getAsBigDecimal();
-      return BuiltinOperators.toValue(bd);
+      return ValueSupport.toValue(bd);
     }
   });
 
@@ -193,7 +193,7 @@ public class DefaultFunctions
       if((lv < Short.MIN_VALUE) || (lv > Short.MAX_VALUE)) {
         throw new EvalException("Int value '" + lv + "' out of range ");
       }
-      return BuiltinOperators.toValue(lv);
+      return ValueSupport.toValue(lv);
     }
   });
 
@@ -201,7 +201,7 @@ public class DefaultFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       int lv = param1.getAsLongInt();
-      return BuiltinOperators.toValue(lv);
+      return ValueSupport.toValue(lv);
     }
   });
 
@@ -212,14 +212,14 @@ public class DefaultFunctions
       if((dv < Float.MIN_VALUE) || (dv > Float.MAX_VALUE)) {
         throw new EvalException("Single value '" + dv + "' out of range ");
       }
-      return BuiltinOperators.toValue(dv.floatValue());
+      return ValueSupport.toValue(dv.floatValue());
     }
   });
 
   public static final Function CSTR = registerFunc(new Func1("CStr") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(param1.getAsString());
+      return ValueSupport.toValue(param1.getAsString());
     }
   });
 
@@ -233,14 +233,14 @@ public class DefaultFunctions
   public static final Function ISNULL = registerFunc(new Func1("IsNull") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(param1.isNull());
+      return ValueSupport.toValue(param1.isNull());
     }
   });
 
   public static final Function ISDATE = registerFunc(new Func1("IsDate") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(
+      return ValueSupport.toValue(
           !param1.isNull() &&
           (DefaultDateFunctions.nonNullToDateValue(ctx, param1) != null));
     }
@@ -281,7 +281,7 @@ public class DefaultFunctions
       default:
         throw new EvalException("Unknown type " + type);
       }
-      return BuiltinOperators.toValue(vType);
+      return ValueSupport.toValue(vType);
     }
   });
 
@@ -314,7 +314,7 @@ public class DefaultFunctions
       default:
         throw new EvalException("Unknown type " + type);
       }
-      return BuiltinOperators.toValue(tName);
+      return ValueSupport.toValue(tName);
     }
   });
 

src/main/java/com/healthmarketscience/jackcess/impl/expr/DefaultNumberFunctions.java

@@ -50,14 +50,14 @@ public class DefaultNumberFunctions
       case DATE_TIME:
         // dates/times get converted to date doubles for arithmetic
         double result = Math.abs(param1.getAsDouble());
-        return BuiltinOperators.toDateValue(ctx, mathType, result, param1, null);
+        return ValueSupport.toDateValue(ctx, mathType, result, param1, null);
       case LONG:
-        return BuiltinOperators.toValue(Math.abs(param1.getAsLongInt()));
+        return ValueSupport.toValue(Math.abs(param1.getAsLongInt()));
       case DOUBLE:
-        return BuiltinOperators.toValue(Math.abs(param1.getAsDouble()));
+        return ValueSupport.toValue(Math.abs(param1.getAsDouble()));
       case STRING:
       case BIG_DEC:
-        return BuiltinOperators.toValue(param1.getAsBigDecimal().abs(
+        return ValueSupport.toValue(param1.getAsBigDecimal().abs(
                                             NumberFormatter.DEC_MATH_CONTEXT));
       default:
         throw new EvalException("Unexpected type " + mathType);
@@ -68,21 +68,21 @@ public class DefaultNumberFunctions
   public static final Function ATAN = registerFunc(new Func1("Atan") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(Math.atan(param1.getAsDouble()));
+      return ValueSupport.toValue(Math.atan(param1.getAsDouble()));
     }
   });
 
   public static final Function COS = registerFunc(new Func1("Cos") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(Math.cos(param1.getAsDouble()));
+      return ValueSupport.toValue(Math.cos(param1.getAsDouble()));
     }
   });
 
   public static final Function EXP = registerFunc(new Func1("Exp") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(Math.exp(param1.getAsDouble()));
+      return ValueSupport.toValue(Math.exp(param1.getAsDouble()));
     }
   });
 
@@ -92,7 +92,7 @@ public class DefaultNumberFunctions
       if(param1.getType().isIntegral()) {
         return param1;
       }
-      return BuiltinOperators.toValue(param1.getAsDouble().intValue());
+      return ValueSupport.toValue(param1.getAsDouble().intValue());
     }
   });
 
@@ -102,14 +102,14 @@ public class DefaultNumberFunctions
       if(param1.getType().isIntegral()) {
         return param1;
       }
-      return BuiltinOperators.toValue((int)Math.floor(param1.getAsDouble()));
+      return ValueSupport.toValue((int)Math.floor(param1.getAsDouble()));
     }
   });
 
   public static final Function LOG = registerFunc(new Func1("Log") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(Math.log(param1.getAsDouble()));
+      return ValueSupport.toValue(Math.log(param1.getAsDouble()));
     }
   });
 
@@ -121,7 +121,7 @@ public class DefaultNumberFunctions
     @Override
     protected Value evalVar(EvalContext ctx, Value[] params) {
       Integer seed = ((params.length > 0) ? params[0].getAsLongInt() : null);
-      return BuiltinOperators.toValue(ctx.getRandom(seed));
+      return ValueSupport.toValue(ctx.getRandom(seed));
     }
   });
 
@@ -141,7 +141,7 @@ public class DefaultNumberFunctions
       }
       BigDecimal bd = param1.getAsBigDecimal()
         .setScale(scale, NumberFormatter.ROUND_MODE);
-      return BuiltinOperators.toValue(bd);
+      return ValueSupport.toValue(bd);
     }
   });
 
@@ -154,9 +154,9 @@ public class DefaultNumberFunctions
       } else {
         val = param1.getAsBigDecimal().signum();
       }
-      return ((val > 0) ? BuiltinOperators.ONE_VAL :
-              ((val < 0) ? BuiltinOperators.NEG_ONE_VAL :
-               BuiltinOperators.ZERO_VAL));
+      return ((val > 0) ? ValueSupport.ONE_VAL :
+              ((val < 0) ? ValueSupport.NEG_ONE_VAL :
+               ValueSupport.ZERO_VAL));
     }
   });
 
@@ -167,21 +167,21 @@ public class DefaultNumberFunctions
       if(dv < 0.0d) {
         throw new EvalException("Invalid value '" + dv + "'");
       }
-      return BuiltinOperators.toValue(Math.sqrt(dv));
+      return ValueSupport.toValue(Math.sqrt(dv));
     }
   });
 
   public static final Function SIN = registerFunc(new Func1("Sin") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(Math.sin(param1.getAsDouble()));
+      return ValueSupport.toValue(Math.sin(param1.getAsDouble()));
     }
   });
 
   public static final Function TAN = registerFunc(new Func1("Tan") {
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
-      return BuiltinOperators.toValue(Math.tan(param1.getAsDouble()));
+      return ValueSupport.toValue(Math.tan(param1.getAsDouble()));
     }
   });
 

src/main/java/com/healthmarketscience/jackcess/impl/expr/DefaultTextFunctions.java

@@ -51,7 +51,7 @@ public class DefaultTextFunctions
         throw new EvalException("Character code '" + lv +
                                         "' out of range ");
       }
-      return BuiltinOperators.toValue(lv);
+      return ValueSupport.toValue(lv);
     }
   });
 
@@ -64,7 +64,7 @@ public class DefaultTextFunctions
         throw new EvalException("No characters in string");
       }
       int lv = str.charAt(0);
-      return BuiltinOperators.toValue(lv);
+      return ValueSupport.toValue(lv);
     }
   });
 
@@ -77,7 +77,7 @@ public class DefaultTextFunctions
                                         "' out of range ");
       }
       char[] cs = Character.toChars(lv);
-      return BuiltinOperators.toValue(new String(cs));
+      return ValueSupport.toValue(new String(cs));
     }
   });
 
@@ -86,7 +86,7 @@ public class DefaultTextFunctions
     protected Value eval1(EvalContext ctx, Value param1) {
       int lv = param1.getAsLongInt();
       char[] cs = Character.toChars(lv);
-      return BuiltinOperators.toValue(new String(cs));
+      return ValueSupport.toValue(new String(cs));
     }
   });
 
@@ -98,7 +98,7 @@ public class DefaultTextFunctions
       if(bd.compareTo(BigDecimal.ZERO) >= 0) {
         str = " " + str;
       }
-      return BuiltinOperators.toValue(str);
+      return ValueSupport.toValue(str);
     }
   });
 
@@ -119,7 +119,7 @@ public class DefaultTextFunctions
       String s1 = param1.getAsString();
       int s1Len = s1.length();
       if(s1Len == 0) {
-        return BuiltinOperators.ZERO_VAL;
+        return ValueSupport.ZERO_VAL;
       }
       Value param2 = params[idx++];
       if(param2.isNull()) {
@@ -129,7 +129,7 @@ public class DefaultTextFunctions
       int s2Len = s2.length();
       if(s2Len == 0) {
         // 1 based offsets
-        return BuiltinOperators.toValue(start + 1);
+        return ValueSupport.toValue(start + 1);
       }
       boolean ignoreCase = true;
       if(params.length > 3) {
@@ -139,11 +139,11 @@ public class DefaultTextFunctions
       while(start < end) {
         if(s1.regionMatches(ignoreCase, start, s2, 0, s2Len)) {
           // 1 based offsets
-          return BuiltinOperators.toValue(start + 1);
+          return ValueSupport.toValue(start + 1);
         }
         ++start;
       }
-      return BuiltinOperators.ZERO_VAL;
+      return ValueSupport.ZERO_VAL;
     }
   });
 
@@ -157,7 +157,7 @@ public class DefaultTextFunctions
       String s1 = param1.getAsString();
       int s1Len = s1.length();
       if(s1Len == 0) {
-        return BuiltinOperators.ZERO_VAL;
+        return ValueSupport.ZERO_VAL;
       }
       Value param2 = params[1];
       if(param2.isNull()) {
@@ -168,7 +168,7 @@ public class DefaultTextFunctions
       int start = s1Len - 1;
       if(s2Len == 0) {
         // 1 based offsets
-        return BuiltinOperators.toValue(start + 1);
+        return ValueSupport.toValue(start + 1);
       }
       if(params.length > 2) {
         start = params[2].getAsLongInt();
@@ -186,11 +186,11 @@ public class DefaultTextFunctions
       while(start >= 0) {
         if(s1.regionMatches(ignoreCase, start, s2, 0, s2Len)) {
           // 1 based offsets
-          return BuiltinOperators.toValue(start + 1);
+          return ValueSupport.toValue(start + 1);
         }
         --start;
       }
-      return BuiltinOperators.ZERO_VAL;
+      return ValueSupport.ZERO_VAL;
     }
   });
 
@@ -198,7 +198,7 @@ public class DefaultTextFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       String str = param1.getAsString();
-      return BuiltinOperators.toValue(str.toLowerCase());
+      return ValueSupport.toValue(str.toLowerCase());
     }
   });
 
@@ -206,7 +206,7 @@ public class DefaultTextFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       String str = param1.getAsString();
-      return BuiltinOperators.toValue(str.toUpperCase());
+      return ValueSupport.toValue(str.toUpperCase());
     }
   });
 
@@ -218,7 +218,7 @@ public class DefaultTextFunctions
       }
       String str = param1.getAsString();
       int len = Math.min(str.length(), param2.getAsLongInt());
-      return BuiltinOperators.toValue(str.substring(0, len));
+      return ValueSupport.toValue(str.substring(0, len));
     }
   });
 
@@ -231,7 +231,7 @@ public class DefaultTextFunctions
       String str = param1.getAsString();
       int strLen = str.length();
       int len = Math.min(strLen, param2.getAsLongInt());
-      return BuiltinOperators.toValue(str.substring(strLen - len, strLen));
+      return ValueSupport.toValue(str.substring(strLen - len, strLen));
     }
   });
 
@@ -249,7 +249,7 @@ public class DefaultTextFunctions
       int len = Math.min(
           ((params.length > 2) ? params[2].getAsLongInt() : strLen),
           (strLen - start));
-      return BuiltinOperators.toValue(str.substring(start, start + len));
+      return ValueSupport.toValue(str.substring(start, start + len));
     }
   });
 
@@ -257,7 +257,7 @@ public class DefaultTextFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       String str = param1.getAsString();
-      return BuiltinOperators.toValue(str.length());
+      return ValueSupport.toValue(str.length());
     }
   });
 
@@ -265,7 +265,7 @@ public class DefaultTextFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       String str = param1.getAsString();
-      return BuiltinOperators.toValue(trim(str, true, false));
+      return ValueSupport.toValue(trim(str, true, false));
     }
   });
 
@@ -273,7 +273,7 @@ public class DefaultTextFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       String str = param1.getAsString();
-      return BuiltinOperators.toValue(trim(str, false, true));
+      return ValueSupport.toValue(trim(str, false, true));
     }
   });
 
@@ -281,7 +281,7 @@ public class DefaultTextFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       String str = param1.getAsString();
-      return BuiltinOperators.toValue(trim(str, true, true));
+      return ValueSupport.toValue(trim(str, true, true));
     }
   });
 
@@ -289,7 +289,7 @@ public class DefaultTextFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       int lv = param1.getAsLongInt();
-      return BuiltinOperators.toValue(nchars(lv, ' '));
+      return ValueSupport.toValue(nchars(lv, ' '));
     }
   });
 
@@ -299,7 +299,7 @@ public class DefaultTextFunctions
       Value param1 = params[0];
       Value param2 = params[1];
       if(param1.isNull() || param2.isNull()) {
-        return BuiltinOperators.NULL_VAL;
+        return ValueSupport.NULL_VAL;
       }
       String s1 = param1.getAsString();
       String s2 = param2.getAsString();
@@ -310,9 +310,9 @@ public class DefaultTextFunctions
       int cmp = (ignoreCase ?
                  s1.compareToIgnoreCase(s2) : s1.compareTo(s2));
       // stupid java doesn't return 1, -1, 0...
-      return ((cmp < 0) ? BuiltinOperators.NEG_ONE_VAL :
-              ((cmp > 0) ? BuiltinOperators.ONE_VAL :
-               BuiltinOperators.ZERO_VAL));
+      return ((cmp < 0) ? ValueSupport.NEG_ONE_VAL :
+              ((cmp > 0) ? ValueSupport.ONE_VAL :
+               ValueSupport.ZERO_VAL));
     }
   });
 
@@ -320,11 +320,11 @@ public class DefaultTextFunctions
     @Override
     protected Value eval2(EvalContext ctx, Value param1, Value param2) {
       if(param1.isNull() || param2.isNull()) {
-        return BuiltinOperators.NULL_VAL;
+        return ValueSupport.NULL_VAL;
       }
       int lv = param1.getAsLongInt();
       char c = (char)(param2.getAsString().charAt(0) % 256);
-      return BuiltinOperators.toValue(nchars(lv, c));
+      return ValueSupport.toValue(nchars(lv, c));
     }
   });
 
@@ -332,7 +332,7 @@ public class DefaultTextFunctions
     @Override
     protected Value eval1(EvalContext ctx, Value param1) {
       String str = param1.getAsString();
-      return BuiltinOperators.toValue(
+      return ValueSupport.toValue(
           new StringBuilder(str).reverse().toString());
     }
   });

src/main/java/com/healthmarketscience/jackcess/impl/expr/Expressionator.java

@@ -401,11 +401,11 @@ public class Expressionator
   private static final Expr THIS_COL_VALUE = new EThisValue();
 
   private static final Expr NULL_VALUE = new EConstValue(
-      BuiltinOperators.NULL_VAL, "Null");
+      ValueSupport.NULL_VAL, "Null");
   private static final Expr TRUE_VALUE = new EConstValue(
-      BuiltinOperators.TRUE_VAL, "True");
+      ValueSupport.TRUE_VAL, "True");
   private static final Expr FALSE_VALUE = new EConstValue(
-      BuiltinOperators.FALSE_VAL, "False");
+      ValueSupport.FALSE_VAL, "False");
 
 
   private Expressionator() {}
@@ -1302,7 +1302,7 @@ public class Expressionator
   {
     switch(valType) {
     case STRING:
-      return BuiltinOperators.toValue((String)value);
+      return ValueSupport.toValue((String)value);
     case DATE:
       return new DateValue((Date)value, sdf);
     case TIME:
@@ -1310,11 +1310,11 @@ public class Expressionator
     case DATE_TIME:
       return new DateTimeValue((Date)value, sdf);
     case LONG:
-      return BuiltinOperators.toValue((Integer)value);
+      return ValueSupport.toValue((Integer)value);
     case DOUBLE:
-      return BuiltinOperators.toValue((Double)value);
+      return ValueSupport.toValue((Double)value);
     case BIG_DEC:
-      return BuiltinOperators.toValue((BigDecimal)value);
+      return ValueSupport.toValue((BigDecimal)value);
     default:
       throw new ParseException("unexpected literal type " + valType);
     }

src/main/java/com/healthmarketscience/jackcess/impl/expr/StringValue.java

@@ -75,7 +75,7 @@ public class StringValue extends BaseValue
     if(_num == null) {
       // see if it is parseable as a number
       try {
-        _num = BuiltinOperators.normalize(new BigDecimal(_val));
+        _num = ValueSupport.normalize(new BigDecimal(_val));
         return (BigDecimal)_num;
       } catch(NumberFormatException nfe) {
         _num = NOT_A_NUMBER;

src/main/java/com/healthmarketscience/jackcess/impl/expr/ValueSupport.java

@@ -0,0 +1,162 @@
+/*
+Copyright (c) 2018 James Ahlborn
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package com.healthmarketscience.jackcess.impl.expr;
+
+import java.math.BigDecimal;
+import java.text.DateFormat;
+import java.util.Date;
+
+import com.healthmarketscience.jackcess.expr.EvalContext;
+import com.healthmarketscience.jackcess.expr.EvalException;
+import com.healthmarketscience.jackcess.expr.Value;
+import com.healthmarketscience.jackcess.impl.ColumnImpl;
+
+/**
+ *
+ * @author James Ahlborn
+ */
+public class ValueSupport
+{
+  public static final Value NULL_VAL = new BaseValue() {
+    @Override public boolean isNull() {
+      return true;
+    }
+    public Type getType() {
+      return Type.NULL;
+    }
+    public Object get() {
+      return null;
+    }
+  };
+  // access seems to like -1 for true and 0 for false (boolean values are
+  // basically an illusion)
+  public static final Value TRUE_VAL = new LongValue(-1);
+  public static final Value FALSE_VAL = new LongValue(0);
+  public static final Value EMPTY_STR_VAL = new StringValue("");
+  public static final Value ZERO_VAL = FALSE_VAL;
+  public static final Value NEG_ONE_VAL = TRUE_VAL;
+  public static final Value ONE_VAL = new LongValue(1);
+
+  private ValueSupport() {}
+
+  public static Value toValue(boolean b) {
+    return (b ? TRUE_VAL : FALSE_VAL);
+  }
+
+  public static Value toValue(String s) {
+    return new StringValue(s);
+  }
+
+  public static Value toValue(int i) {
+    return new LongValue(i);
+  }
+
+  public static Value toValue(Integer i) {
+    return new LongValue(i);
+  }
+
+  public static Value toValue(float f) {
+    return new DoubleValue((double)f);
+  }
+
+  public static Value toValue(double s) {
+    return new DoubleValue(s);
+  }
+
+  public static Value toValue(Double s) {
+    return new DoubleValue(s);
+  }
+
+  public static Value toValue(BigDecimal s) {
+    return new BigDecimalValue(normalize(s));
+  }
+
+  public static Value toValue(Value.Type type, double dd, DateFormat fmt) {
+    return toValue(type, new Date(ColumnImpl.fromDateDouble(
+                                      dd, fmt.getCalendar())), fmt);
+  }
+
+  public static Value toValue(EvalContext ctx, Value.Type type, Date d) {
+    return toValue(type, d, getDateFormatForType(ctx, type));
+  }
+
+  public static Value toValue(Value.Type type, Date d, DateFormat fmt) {
+    switch(type) {
+    case DATE:
+      return new DateValue(d, fmt);
+    case TIME:
+      return new TimeValue(d, fmt);
+    case DATE_TIME:
+      return new DateTimeValue(d, fmt);
+    default:
+      throw new EvalException("Unexpected date/time type " + type);
+    }
+  }
+
+  static Value toDateValue(EvalContext ctx, Value.Type type, double v,
+                           Value param1, Value param2)
+  {
+    DateFormat fmt = null;
+    if((param1 instanceof BaseDateValue) && (param1.getType() == type)) {
+      fmt = ((BaseDateValue)param1).getFormat();
+    } else if((param2 instanceof BaseDateValue) && (param2.getType() == type)) {
+      fmt = ((BaseDateValue)param2).getFormat();
+    } else {
+      fmt = getDateFormatForType(ctx, type);
+    }
+
+    Date d = new Date(ColumnImpl.fromDateDouble(v, fmt.getCalendar()));
+
+    return toValue(type, d, fmt);
+  }
+
+  static DateFormat getDateFormatForType(EvalContext ctx, Value.Type type) {
+      String fmtStr = null;
+      switch(type) {
+      case DATE:
+        fmtStr = ctx.getTemporalConfig().getDefaultDateFormat();
+        break;
+      case TIME:
+        fmtStr = ctx.getTemporalConfig().getDefaultTimeFormat();
+        break;
+      case DATE_TIME:
+        fmtStr = ctx.getTemporalConfig().getDefaultDateTimeFormat();
+        break;
+      default:
+        throw new EvalException("Unexpected date/time type " + type);
+      }
+      return ctx.createDateFormat(fmtStr);
+  }
+
+  /**
+   * Converts the given BigDecimal to the minimal scale >= 0;
+   */
+  static BigDecimal normalize(BigDecimal bd) {
+    if(bd.scale() == 0) {
+      return bd;
+    }
+    // handle a bug in the jdk which doesn't strip zero values
+    if(bd.compareTo(BigDecimal.ZERO) == 0) {
+      return BigDecimal.ZERO;
+    }
+    bd = bd.stripTrailingZeros();
+    if(bd.scale() < 0) {
+      bd = bd.setScale(0);
+    }
+    return bd;
+  }
+}

src/test/java/com/healthmarketscience/jackcess/PropertyExpressionTest.java

@@ -26,9 +26,9 @@ import com.healthmarketscience.jackcess.expr.Function;
 import com.healthmarketscience.jackcess.expr.FunctionLookup;
 import com.healthmarketscience.jackcess.expr.TemporalConfig;
 import com.healthmarketscience.jackcess.expr.Value;
-import com.healthmarketscience.jackcess.impl.expr.BuiltinOperators;
 import com.healthmarketscience.jackcess.impl.expr.DefaultFunctions;
 import com.healthmarketscience.jackcess.impl.expr.FunctionSupport;
+import com.healthmarketscience.jackcess.impl.expr.ValueSupport;
 import junit.framework.TestCase;
 
 import static com.healthmarketscience.jackcess.Database.*;
@@ -354,7 +354,7 @@ public class PropertyExpressionTest extends TestCase
     @Override
     protected Value eval0(EvalContext ctx) {
       Object val = ctx.get("someKey");
-      return BuiltinOperators.toValue("FOO_" + val);
+      return ValueSupport.toValue("FOO_" + val);
     }
   };
 }

src/test/java/com/healthmarketscience/jackcess/impl/expr/ExpressionatorTest.java

@@ -429,12 +429,12 @@ public class ExpressionatorTest extends TestCase
     TestContext tc = new TestContext() {
       @Override
       public Value getThisColumnValue() {
-        return BuiltinOperators.toValue(23.0);
+        return ValueSupport.toValue(23.0);
       }
 
       @Override
       public Value getIdentifierValue(Identifier identifier) {
-        return BuiltinOperators.toValue(23.0);
+        return ValueSupport.toValue(23.0);
       }
     };
 
@@ -536,7 +536,7 @@ public class ExpressionatorTest extends TestCase
   }
 
   private static Boolean evalCondition(String exprStr, String thisVal) {
-    TestContext tc = new TestContext(BuiltinOperators.toValue(thisVal));
+    TestContext tc = new TestContext(ValueSupport.toValue(thisVal));
     Expression expr = Expressionator.parse(
         Expressionator.Type.FIELD_VALIDATOR, exprStr, null, tc);
     return (Boolean)expr.eval(tc);
@@ -552,7 +552,7 @@ public class ExpressionatorTest extends TestCase
   }
 
   static BigDecimal toBD(BigDecimal bd) {
-    return BuiltinOperators.normalize(bd);
+    return ValueSupport.normalize(bd);
   }
 
   private static class TestContext