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 * 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
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package org.apache.commons.configuration2.tree;

import org.apache.commons.lang3.builder.EqualsBuilder;
import org.apache.commons.lang3.builder.HashCodeBuilder;
import org.apache.commons.lang3.builder.ToStringBuilder;

 A class representing the various symbols that are supported in keys recognized by DefaultExpressionEngine. 
 An instance of this class is associated with each instance of DefaultExpressionEngine. It determines which concrete symbols are used to define elements like separators, attributes, etc. within a configuration key. 
 Instances are created using the nested Builder class. They are immutable and can be shared between arbitrary components. 
Since:
2.0/**
 * <p>
 * A class representing the various symbols that are supported in keys
 * recognized by {@link DefaultExpressionEngine}.
 * </p>
 * <p>
 * An instance of this class is associated with each instance of
 * {@code DefaultExpressionEngine}. It determines which concrete symbols are
 * used to define elements like separators, attributes, etc. within a
 * configuration key.
 * </p>
 * <p>
 * Instances are created using the nested {@code Builder} class. They are
 * immutable and can be shared between arbitrary components.
 * </p>
 *
 * @since 2.0
 */
public final class DefaultExpressionEngineSymbols
{
    
Constant for the default property delimiter. /** Constant for the default property delimiter. */
    public static final String DEFAULT_PROPERTY_DELIMITER = ".";

    
Constant for the default escaped property delimiter. /** Constant for the default escaped property delimiter. */
    public static final String DEFAULT_ESCAPED_DELIMITER = DEFAULT_PROPERTY_DELIMITER
            + DEFAULT_PROPERTY_DELIMITER;

    
Constant for the default attribute start marker. /** Constant for the default attribute start marker. */
    public static final String DEFAULT_ATTRIBUTE_START = "[@";

    
Constant for the default attribute end marker. /** Constant for the default attribute end marker. */
    public static final String DEFAULT_ATTRIBUTE_END = "]";

    
Constant for the default index start marker. /** Constant for the default index start marker. */
    public static final String DEFAULT_INDEX_START = "(";

    
Constant for the default index end marker. /** Constant for the default index end marker. */
    public static final String DEFAULT_INDEX_END = ")";

    
An instance with default symbols. This instance is used by the default instance of DefaultExpressionEngine. /**
     * An instance with default symbols. This instance is used by the default
     * instance of {@code DefaultExpressionEngine}.
     */
    public static final DefaultExpressionEngineSymbols DEFAULT_SYMBOLS =
            createDefaultSmybols();

    
Stores the property delimiter. /** Stores the property delimiter. */
    private final String propertyDelimiter;

    
Stores the escaped property delimiter. /** Stores the escaped property delimiter. */
    private final String escapedDelimiter;

    
Stores the attribute start marker. /** Stores the attribute start marker. */
    private final String attributeStart;

    
Stores the attribute end marker. /** Stores the attribute end marker. */
    private final String attributeEnd;

    
Stores the index start marker. /** Stores the index start marker. */
    private final String indexStart;

    
stores the index end marker. /** stores the index end marker. */
    private final String indexEnd;

    
Creates a new instance of DefaultExpressionEngineSymbols. 
Params:
b – the builder for defining the properties of this instance/**
     * Creates a new instance of {@code DefaultExpressionEngineSymbols}.
     *
     * @param b the builder for defining the properties of this instance
     */
    private DefaultExpressionEngineSymbols(final Builder b)
    {
        propertyDelimiter = b.propertyDelimiter;
        escapedDelimiter = b.escapedDelimiter;
        indexStart = b.indexStart;
        indexEnd = b.indexEnd;
        attributeStart = b.attributeStart;
        attributeEnd = b.attributeEnd;
    }

    
Returns the string used as delimiter in property keys.
Returns:
the property delimiter/**
     * Returns the string used as delimiter in property keys.
     *
     * @return the property delimiter
     */
    public String getPropertyDelimiter()
    {
        return propertyDelimiter;
    }

    
Returns the string representing an escaped property delimiter.
Returns:
the escaped property delimiter/**
     * Returns the string representing an escaped property delimiter.
     *
     * @return the escaped property delimiter
     */
    public String getEscapedDelimiter()
    {
        return escapedDelimiter;
    }

    
Returns the string representing an attribute start marker.
Returns:
the attribute start marker/**
     * Returns the string representing an attribute start marker.
     *
     * @return the attribute start marker
     */
    public String getAttributeStart()
    {
        return attributeStart;
    }

    
Returns the string representing an attribute end marker.
Returns:
the attribute end marker/**
     * Returns the string representing an attribute end marker.
     *
     * @return the attribute end marker
     */
    public String getAttributeEnd()
    {
        return attributeEnd;
    }

    
Returns the string representing the start of an index in a property key.
Returns:
the index start marker/**
     * Returns the string representing the start of an index in a property key.
     *
     * @return the index start marker
     */
    public String getIndexStart()
    {
        return indexStart;
    }

    
Returns the string representing the end of an index in a property key.
Returns:
the index end marker/**
     * Returns the string representing the end of an index in a property key.
     *
     * @return the index end marker
     */
    public String getIndexEnd()
    {
        return indexEnd;
    }

    
Returns a hash code for this object.
Returns:
a hash code/**
     * Returns a hash code for this object.
     *
     * @return a hash code
     */
    @Override
    public int hashCode()
    {
        return new HashCodeBuilder().append(getPropertyDelimiter())
                .append(getEscapedDelimiter()).append(getIndexStart())
                .append(getIndexEnd()).append(getAttributeStart())
                .append(getAttributeEnd()).toHashCode();
    }

    
Compares this object with another one. Two instances of DefaultExpressionEngineSymbols are considered equal if all of their properties are equal. 
Params:
obj – the object to compare to
Returns:
a flag whether these objects are equal/**
     * Compares this object with another one. Two instances of
     * {@code DefaultExpressionEngineSymbols} are considered equal if all of
     * their properties are equal.
     *
     * @param obj the object to compare to
     * @return a flag whether these objects are equal
     */
    @Override
    public boolean equals(final Object obj)
    {
        if (this == obj)
        {
            return true;
        }
        if (!(obj instanceof DefaultExpressionEngineSymbols))
        {
            return false;
        }

        final DefaultExpressionEngineSymbols c = (DefaultExpressionEngineSymbols) obj;
        return new EqualsBuilder()
                .append(getPropertyDelimiter(), c.getPropertyDelimiter())
                .append(getEscapedDelimiter(), c.getEscapedDelimiter())
                .append(getIndexStart(), c.getIndexStart())
                .append(getIndexEnd(), c.getIndexEnd())
                .append(getAttributeStart(), c.getAttributeStart())
                .append(getAttributeEnd(), c.getAttributeEnd()).isEquals();
    }

    
Returns a string representation for this object. This string contains the
values of all properties.
Returns:
a string for this object/**
     * Returns a string representation for this object. This string contains the
     * values of all properties.
     *
     * @return a string for this object
     */
    @Override
    public String toString()
    {
        return new ToStringBuilder(this)
                .append("propertyDelimiter", getPropertyDelimiter())
                .append("escapedDelimiter", getEscapedDelimiter())
                .append("indexStart", getIndexStart())
                .append("indexEnd", getIndexEnd())
                .append("attributeStart", getAttributeStart())
                .append("attributeEnd", getAttributeEnd()).toString();
    }

    
Creates the DefaultExpressionEngineSymbols object with default symbols. 
Returns:
the default symbols instance/**
     * Creates the {@code DefaultExpressionEngineSymbols} object with default
     * symbols.
     *
     * @return the default symbols instance
     */
    private static DefaultExpressionEngineSymbols createDefaultSmybols()
    {
        return new Builder().setPropertyDelimiter(DEFAULT_PROPERTY_DELIMITER)
                .setEscapedDelimiter(DEFAULT_ESCAPED_DELIMITER)
                .setIndexStart(DEFAULT_INDEX_START)
                .setIndexEnd(DEFAULT_INDEX_END)
                .setAttributeStart(DEFAULT_ATTRIBUTE_START)
                .setAttributeEnd(DEFAULT_ATTRIBUTE_END).create();
    }

    
A builder class for creating instances of DefaultExpressionEngineSymbols. /**
     * A builder class for creating instances of
     * {@code DefaultExpressionEngineSymbols}.
     */
    public static class Builder
    {
        
Stores the property delimiter. /** Stores the property delimiter. */
        private String propertyDelimiter;

        
Stores the escaped property delimiter. /** Stores the escaped property delimiter. */
        private String escapedDelimiter;

        
Stores the attribute start marker. /** Stores the attribute start marker. */
        private String attributeStart;

        
Stores the attribute end marker. /** Stores the attribute end marker. */
        private String attributeEnd;

        
Stores the index start marker. /** Stores the index start marker. */
        private String indexStart;

        
stores the index end marker. /** stores the index end marker. */
        private String indexEnd;

        
Creates a new, uninitialized instance of Builder. All symbols are undefined. /**
         * Creates a new, uninitialized instance of {@code Builder}. All symbols
         * are undefined.
         */
        public Builder()
        {
        }

        
Creates a new instance of Builder whose properties are initialized from the passed in DefaultExpressionEngineSymbols object. This is useful if symbols are to be created which are similar to the passed in instance. 
Params:
c – the DefaultExpressionEngineSymbols object serving as starting point for this builder/**
         * Creates a new instance of {@code Builder} whose properties are
         * initialized from the passed in {@code DefaultExpressionEngineSymbols}
         * object. This is useful if symbols are to be created which are similar
         * to the passed in instance.
         *
         * @param c the {@code DefaultExpressionEngineSymbols} object serving as
         *        starting point for this builder
         */
        public Builder(final DefaultExpressionEngineSymbols c)
        {
            propertyDelimiter = c.getPropertyDelimiter();
            escapedDelimiter = c.getEscapedDelimiter();
            indexStart = c.getIndexStart();
            indexEnd = c.getIndexEnd();
            attributeStart = c.getAttributeStart();
            attributeEnd = c.getAttributeEnd();
        }

        
Sets the string representing a delimiter for properties.
Params:
d – the property delimiter
Returns:
a reference to this object for method chaining/**
         * Sets the string representing a delimiter for properties.
         *
         * @param d the property delimiter
         * @return a reference to this object for method chaining
         */
        public Builder setPropertyDelimiter(final String d)
        {
            propertyDelimiter = d;
            return this;
        }

        
Sets the string representing an escaped property delimiter. With this
string a delimiter that belongs to the key of a property can be
escaped. If for instance "." is used as property delimiter,
you can set the escaped delimiter to "\." and can then
escape the delimiter with a back slash.
Params:
ed – the escaped property delimiter
Returns:
a reference to this object for method chaining/**
         * Sets the string representing an escaped property delimiter. With this
         * string a delimiter that belongs to the key of a property can be
         * escaped. If for instance &quot;.&quot; is used as property delimiter,
         * you can set the escaped delimiter to &quot;\.&quot; and can then
         * escape the delimiter with a back slash.
         *
         * @param ed the escaped property delimiter
         * @return a reference to this object for method chaining
         */
        public Builder setEscapedDelimiter(final String ed)
        {
            escapedDelimiter = ed;
            return this;
        }

        
Sets the string representing the start of an index in a property key.
Index start and end marker are used together to detect indices in a
property key.
Params:
is – the index start
Returns:
a reference to this object for method chaining/**
         * Sets the string representing the start of an index in a property key.
         * Index start and end marker are used together to detect indices in a
         * property key.
         *
         * @param is the index start
         * @return a reference to this object for method chaining
         */
        public Builder setIndexStart(final String is)
        {
            indexStart = is;
            return this;
        }

        
Sets the string representing the end of an index in a property key.
Params:
ie – the index end
Returns:
a reference to this object for method chaining/**
         * Sets the string representing the end of an index in a property key.
         *
         * @param ie the index end
         * @return a reference to this object for method chaining
         */
        public Builder setIndexEnd(final String ie)
        {
            indexEnd = ie;
            return this;
        }

        
Sets the string representing the start marker of an attribute in a
property key. Attribute start and end marker are used together to
detect attributes in a property key.
Params:
as – the attribute start marker
Returns:
a reference to this object for method chaining/**
         * Sets the string representing the start marker of an attribute in a
         * property key. Attribute start and end marker are used together to
         * detect attributes in a property key.
         *
         * @param as the attribute start marker
         * @return a reference to this object for method chaining
         */
        public Builder setAttributeStart(final String as)
        {
            attributeStart = as;
            return this;
        }

        
Sets the string representing the end marker of an attribute in a
property key.
Params:
ae – the attribute end marker
Returns:
a reference to this object for method chaining/**
         * Sets the string representing the end marker of an attribute in a
         * property key.
         *
         * @param ae the attribute end marker
         * @return a reference to this object for method chaining
         */
        public Builder setAttributeEnd(final String ae)
        {
            attributeEnd = ae;
            return this;
        }

        
Creates the DefaultExpressionEngineSymbols instance based on the properties set for this builder object. This method does not change the state of this builder. So it is possible to change properties and create another DefaultExpressionEngineSymbols instance. 
Returns:
the newly created DefaultExpressionEngineSymbols instance/**
         * Creates the {@code DefaultExpressionEngineSymbols} instance based on
         * the properties set for this builder object. This method does not
         * change the state of this builder. So it is possible to change
         * properties and create another {@code DefaultExpressionEngineSymbols}
         * instance.
         *
         * @return the newly created {@code DefaultExpressionEngineSymbols}
         *         instance
         */
        public DefaultExpressionEngineSymbols create()
        {
            return new DefaultExpressionEngineSymbols(this);
        }
    }
}