using System; | |
using System.Text; | |
using System.Globalization; | |
/** | |
* | |
* Licensed to the Apache Software Foundation (ASF) under one or more | |
* contributor license agreements. See the NOTICE file distributed with | |
* this work for additional information regarding copyright ownership. | |
* The ASF 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. | |
*/ | |
namespace Apache.NMS.Selector | |
{ | |
/// <summary> | |
/// Represents a constant expression. | |
/// </summary> | |
public class ConstantExpression : IExpression | |
{ | |
private object value; | |
public object Value | |
{ | |
get { return value; } | |
} | |
public ConstantExpression(object value) | |
{ | |
this.value = value; | |
} | |
public static ConstantExpression CreateFromDecimal(string text) | |
{ | |
// Long integer specified ? | |
object value; | |
if(text.EndsWith("l") || text.EndsWith("L")) | |
{ | |
text = text.Substring(0, text.Length - 1); | |
value = Int64.Parse(text, CultureInfo.InvariantCulture); | |
} | |
else | |
{ | |
long lvalue = Int64.Parse(text, CultureInfo.InvariantCulture); | |
if(lvalue >= Int32.MinValue && lvalue <= Int32.MaxValue) | |
{ | |
value = (int)lvalue; | |
} | |
else | |
{ | |
value = lvalue; | |
} | |
} | |
return new ConstantExpression(value); | |
} | |
public static ConstantExpression CreateFromHex(string text) | |
{ | |
long lvalue = Convert.ToInt64(text.Substring(2), 16); | |
object value; | |
if(lvalue >= Int32.MinValue && lvalue <= Int32.MaxValue) | |
{ | |
value = (int)lvalue; | |
} | |
else | |
{ | |
value = lvalue; | |
} | |
return new ConstantExpression(value); | |
} | |
public static ConstantExpression CreateFromOctal(string text) | |
{ | |
long lvalue = Convert.ToInt64(text, 8); | |
object value; | |
if(lvalue >= Int32.MinValue && lvalue <= Int32.MaxValue) | |
{ | |
value = (int)lvalue; | |
} | |
else | |
{ | |
value = lvalue; | |
} | |
return new ConstantExpression(value); | |
} | |
public static ConstantExpression CreateFloat(string text) | |
{ | |
double value = Double.Parse(text, CultureInfo.InvariantCulture); | |
return new ConstantExpression(value); | |
} | |
public object Evaluate(MessageEvaluationContext message) | |
{ | |
return value; | |
} | |
public override string ToString() | |
{ | |
if(value == null) | |
{ | |
return "NULL"; | |
} | |
if(value is bool) | |
{ | |
return (bool)value ? "TRUE" : "FALSE"; | |
} | |
if(value is string) | |
{ | |
return EncodeString((string)value); | |
} | |
return value.ToString(); | |
} | |
public override int GetHashCode() | |
{ | |
return (value == null ? 0 : value.GetHashCode()); | |
} | |
/// <summary> | |
/// Encodes the value of string so that it looks like it would look like | |
/// when it was provided in a selector. | |
/// </summary> | |
/// <param name="s">String to be encoded.</param> | |
/// <return>Encoded string.</return> | |
public static string EncodeString(string s) | |
{ | |
StringBuilder b = new StringBuilder(); | |
b.Append('\''); | |
for(int c = 0; c < s.Length; c++) | |
{ | |
char ch = s[c]; | |
if(ch == '\'') | |
{ | |
b.Append(ch); | |
} | |
b.Append(ch); | |
} | |
b.Append('\''); | |
return b.ToString(); | |
} | |
public static readonly BooleanConstantExpression NULL = new BooleanConstantExpression(null); | |
public static readonly BooleanConstantExpression TRUE = new BooleanConstantExpression(true); | |
public static readonly BooleanConstantExpression FALSE = new BooleanConstantExpression(false); | |
} | |
} |