src/main/java/net/hydromatic/linq4j/expressions/ConstantExpression.java - incubator-optiq-linq4j - Git at Google

 /*
 // Licensed to Julian Hyde under one or more contributor license
 // agreements. See the NOTICE file distributed with this work for
 // additional information regarding copyright ownership.
 //
 // Julian Hyde licenses this file to you 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 net.hydromatic.linq4j.expressions;

 import net.hydromatic.linq4j.function.Function1;
 import net.hydromatic.linq4j.function.Functions;

 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Type;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.util.List;

 /**
  * Represents an expression that has a constant value.
  */
 public class ConstantExpression extends Expression {
   public final Object value;

   public ConstantExpression(Type type, Object value) {
     super(ExpressionType.Constant, type);
     this.value = value;
     if (value != null) {
       if (type instanceof Class) {
         Class clazz = (Class) type;
         Primitive primitive = Primitive.of(clazz);
         if (primitive != null) {
           clazz = primitive.boxClass;
         }
         if (!clazz.isInstance(value)) {
           throw new AssertionError(
               "value " + value + " does not match type " + type);
         }
       }
     }
   }

   public Object evaluate(Evaluator evaluator) {
     return value;
   }

   @Override
   public Expression accept(Visitor visitor) {
     return visitor.visit(this);
   }

   @Override
   void accept(ExpressionWriter writer, int lprec, int rprec) {
     if (value == null) {
       if (!writer.requireParentheses(this, lprec, rprec)) {
         writer.append("(").append(type).append(") null");
       }
       return;
     }
     write(writer, value, type);
   }

   private static ExpressionWriter write(ExpressionWriter writer,
       final Object value, Type type) {
     if (value == null) {
       return writer.append("null");
     }
     if (type == null) {
       type = value.getClass();
       if (Primitive.isBox(type)) {
         type = Primitive.ofBox(type).primitiveClass;
       }
     }
     if (value instanceof String) {
       escapeString(writer.getBuf(), (String) value);
       return writer;
     }
     final Primitive primitive = Primitive.of(type);
     if (primitive != null) {
       switch (primitive) {
       case BYTE:
         return writer.append("(byte)").append(((Byte) value).intValue());
       case CHAR:
         return writer.append("(char)")
             .append((int) ((Character) value).charValue());
       case SHORT:
         return writer.append("(short)").append(((Short) value).intValue());
       case LONG:
         return writer.append(value).append("L");
       case FLOAT:
         return writer.append(value).append("F");
       case DOUBLE:
         return writer.append(value).append("D");
       default:
         return writer.append(value);
       }
     }
     final Primitive primitive2 = Primitive.ofBox(type);
     if (primitive2 != null) {
       writer.append(primitive2.boxClass.getSimpleName() + ".valueOf(");
       write(writer, value, primitive2.primitiveClass);
       return writer.append(")");
     }
     if (value instanceof Enum) {
       return writer.append(((Enum) value).getDeclaringClass())
           .append('.')
           .append(((Enum) value).name());
     }
     if (value instanceof BigDecimal) {
       BigDecimal bigDecimal = ((BigDecimal) value).stripTrailingZeros();
       try {
         final int scale = bigDecimal.scale();
         final long exact = bigDecimal.scaleByPowerOfTen(scale).longValueExact();
         writer.append("new java.math.BigDecimal(").append(exact).append("L");
         if (scale != 0) {
           writer.append(", ").append(scale);
         }
         return writer.append(")");
       } catch (ArithmeticException e) {
         return writer.append("new java.math.BigDecimal(\"").append(
             bigDecimal.toString()).append("\")");
       }
     }
     if (value instanceof BigInteger) {
       BigInteger bigInteger = (BigInteger) value;
       return writer.append("new java.math.BigInteger(\"").append(
           bigInteger.toString()).append("\")");
     }
     if (value instanceof Class) {
       Class clazz = (Class) value;
       return writer.append(clazz.getCanonicalName()).append(".class");
     }
     if (value instanceof Types.RecordType) {
       final Types.RecordType recordType = (Types.RecordType) value;
       return writer.append(recordType.getName()).append(".class");
     }
     if (value.getClass().isArray()) {
       writer.append("new ").append(value.getClass().getComponentType());
       list(writer, Primitive.asList(value), "[] {\n", ",\n", "}");
       return writer;
     }
     Constructor constructor = matchingConstructor(value);
     if (constructor != null) {
       final Field[] fields = value.getClass().getFields();
       writer.append("new ").append(value.getClass());
       list(writer,
           Functions.adapt(fields,
               new Function1<Field, Object>() {
                 public Object apply(Field field) {
                   try {
                     return field.get(value);
                   } catch (IllegalAccessException e) {
                     throw new RuntimeException(e);
                   }
                 }
               }),
           "(\n", ",\n", ")");
       return writer;
     }
     return writer.append(value);
   }

   private static void list(ExpressionWriter writer, List list,
       String begin, String sep, String end) {
     writer.begin(begin);
     for (int i = 0; i < list.size(); i++) {
       Object value = list.get(i);
       if (i > 0) {
         writer.append(sep).indent();
       }
       write(writer, value, null);
     }
     writer.end(end);
   }

   private static Constructor matchingConstructor(Object value) {
     final Field[] fields = value.getClass().getFields();
     for (Constructor<?> constructor : value.getClass().getConstructors()) {
       if (argsMatchFields(fields, constructor.getParameterTypes())) {
         return constructor;
       }
     }
     return null;
   }

   private static boolean argsMatchFields(Field[] fields,
       Class<?>[] parameterTypes) {
     if (parameterTypes.length != fields.length) {
       return false;
     }
     for (int i = 0; i < fields.length; i++) {
       if (fields[i].getType() != parameterTypes[i]) {
         return false;
       }
     }
     return true;
   }

   private static void escapeString(StringBuilder buf, String s) {
     buf.append('"');
     int n = s.length();
     char lastChar = 0;
     for (int i = 0; i < n; ++i) {
       char c = s.charAt(i);
       switch (c) {
       case '\\':
         buf.append("\\\\");
         break;
       case '"':
         buf.append("\\\"");
         break;
       case '\n':
         buf.append("\\n");
         break;
       case '\r':
         if (lastChar != '\n') {
           buf.append("\\r");
         }
         break;
       default:
         buf.append(c);
         break;
       }
       lastChar = c;
     }
     buf.append('"');
   }

   @Override
   public boolean equals(Object o) {
     // REVIEW: Should constants with the same value and different type
     // (e.g. 3L and 3) be considered equal.
     if (this == o) {
       return true;
     }
     if (o == null || getClass() != o.getClass()) {
       return false;
     }
     if (!super.equals(o)) {
       return false;
     }

     ConstantExpression that = (ConstantExpression) o;

     if (value != null ? !value.equals(that.value) : that.value != null) {
       return false;
     }

     return true;
   }

   @Override
   public int hashCode() {
     int result = super.hashCode();
     result = 31 * result + (value != null ? value.hashCode() : 0);
     return result;
   }
 }

 // End ConstantExpression.java
	/*
	// Licensed to Julian Hyde under one or more contributor license
	// agreements. See the NOTICE file distributed with this work for
	// additional information regarding copyright ownership.
	//
	// Julian Hyde licenses this file to you 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 net.hydromatic.linq4j.expressions;

	import net.hydromatic.linq4j.function.Function1;
	import net.hydromatic.linq4j.function.Functions;

	import java.lang.reflect.Constructor;
	import java.lang.reflect.Field;
	import java.lang.reflect.Type;
	import java.math.BigDecimal;
	import java.math.BigInteger;
	import java.util.List;

	/**
	* Represents an expression that has a constant value.
	*/
	public class ConstantExpression extends Expression {
	public final Object value;

	public ConstantExpression(Type type, Object value) {
	super(ExpressionType.Constant, type);
	this.value = value;
	if (value != null) {
	if (type instanceof Class) {
	Class clazz = (Class) type;
	Primitive primitive = Primitive.of(clazz);
	if (primitive != null) {
	clazz = primitive.boxClass;
	}
	if (!clazz.isInstance(value)) {
	throw new AssertionError(
	"value " + value + " does not match type " + type);
	}
	}
	}
	}

	public Object evaluate(Evaluator evaluator) {
	return value;
	}

	@Override
	public Expression accept(Visitor visitor) {
	return visitor.visit(this);
	}

	@Override
	void accept(ExpressionWriter writer, int lprec, int rprec) {
	if (value == null) {
	if (!writer.requireParentheses(this, lprec, rprec)) {
	writer.append("(").append(type).append(") null");
	}
	return;
	}
	write(writer, value, type);
	}

	private static ExpressionWriter write(ExpressionWriter writer,
	final Object value, Type type) {
	if (value == null) {
	return writer.append("null");
	}
	if (type == null) {
	type = value.getClass();
	if (Primitive.isBox(type)) {
	type = Primitive.ofBox(type).primitiveClass;
	}
	}
	if (value instanceof String) {
	escapeString(writer.getBuf(), (String) value);
	return writer;
	}
	final Primitive primitive = Primitive.of(type);
	if (primitive != null) {
	switch (primitive) {
	case BYTE:
	return writer.append("(byte)").append(((Byte) value).intValue());
	case CHAR:
	return writer.append("(char)")
	.append((int) ((Character) value).charValue());
	case SHORT:
	return writer.append("(short)").append(((Short) value).intValue());
	case LONG:
	return writer.append(value).append("L");
	case FLOAT:
	return writer.append(value).append("F");
	case DOUBLE:
	return writer.append(value).append("D");
	default:
	return writer.append(value);
	}
	}
	final Primitive primitive2 = Primitive.ofBox(type);
	if (primitive2 != null) {
	writer.append(primitive2.boxClass.getSimpleName() + ".valueOf(");
	write(writer, value, primitive2.primitiveClass);
	return writer.append(")");
	}
	if (value instanceof Enum) {
	return writer.append(((Enum) value).getDeclaringClass())
	.append('.')
	.append(((Enum) value).name());
	}
	if (value instanceof BigDecimal) {
	BigDecimal bigDecimal = ((BigDecimal) value).stripTrailingZeros();
	try {
	final int scale = bigDecimal.scale();
	final long exact = bigDecimal.scaleByPowerOfTen(scale).longValueExact();
	writer.append("new java.math.BigDecimal(").append(exact).append("L");
	if (scale != 0) {
	writer.append(", ").append(scale);
	}
	return writer.append(")");
	} catch (ArithmeticException e) {
	return writer.append("new java.math.BigDecimal(\"").append(
	bigDecimal.toString()).append("\")");
	}
	}
	if (value instanceof BigInteger) {
	BigInteger bigInteger = (BigInteger) value;
	return writer.append("new java.math.BigInteger(\"").append(
	bigInteger.toString()).append("\")");
	}
	if (value instanceof Class) {
	Class clazz = (Class) value;
	return writer.append(clazz.getCanonicalName()).append(".class");
	}
	if (value instanceof Types.RecordType) {
	final Types.RecordType recordType = (Types.RecordType) value;
	return writer.append(recordType.getName()).append(".class");
	}
	if (value.getClass().isArray()) {
	writer.append("new ").append(value.getClass().getComponentType());
	list(writer, Primitive.asList(value), "[] {\n", ",\n", "}");
	return writer;
	}
	Constructor constructor = matchingConstructor(value);
	if (constructor != null) {
	final Field[] fields = value.getClass().getFields();
	writer.append("new ").append(value.getClass());
	list(writer,
	Functions.adapt(fields,
	new Function1<Field, Object>() {
	public Object apply(Field field) {
	try {
	return field.get(value);
	} catch (IllegalAccessException e) {
	throw new RuntimeException(e);
	}
	}
	}),
	"(\n", ",\n", ")");
	return writer;
	}
	return writer.append(value);
	}

	private static void list(ExpressionWriter writer, List list,
	String begin, String sep, String end) {
	writer.begin(begin);
	for (int i = 0; i < list.size(); i++) {
	Object value = list.get(i);
	if (i > 0) {
	writer.append(sep).indent();
	}
	write(writer, value, null);
	}
	writer.end(end);
	}

	private static Constructor matchingConstructor(Object value) {
	final Field[] fields = value.getClass().getFields();
	for (Constructor<?> constructor : value.getClass().getConstructors()) {
	if (argsMatchFields(fields, constructor.getParameterTypes())) {
	return constructor;
	}
	}
	return null;
	}

	private static boolean argsMatchFields(Field[] fields,
	Class<?>[] parameterTypes) {
	if (parameterTypes.length != fields.length) {
	return false;
	}
	for (int i = 0; i < fields.length; i++) {
	if (fields[i].getType() != parameterTypes[i]) {
	return false;
	}
	}
	return true;
	}

	private static void escapeString(StringBuilder buf, String s) {
	buf.append('"');
	int n = s.length();
	char lastChar = 0;
	for (int i = 0; i < n; ++i) {
	char c = s.charAt(i);
	switch (c) {
	case '\\':
	buf.append("\\\\");
	break;
	case '"':
	buf.append("\\\"");
	break;
	case '\n':
	buf.append("\\n");
	break;
	case '\r':
	if (lastChar != '\n') {
	buf.append("\\r");
	}
	break;
	default:
	buf.append(c);
	break;
	}
	lastChar = c;
	}
	buf.append('"');
	}

	@Override
	public boolean equals(Object o) {
	// REVIEW: Should constants with the same value and different type
	// (e.g. 3L and 3) be considered equal.
	if (this == o) {
	return true;
	}
	if (o == null \|\| getClass() != o.getClass()) {
	return false;
	}
	if (!super.equals(o)) {
	return false;
	}

	ConstantExpression that = (ConstantExpression) o;

	if (value != null ? !value.equals(that.value) : that.value != null) {
	return false;
	}

	return true;
	}

	@Override
	public int hashCode() {
	int result = super.hashCode();
	result = 31 * result + (value != null ? value.hashCode() : 0);
	return result;
	}
	}

	// End ConstantExpression.java