package com.github.davidmoten.rx.jdbc;
   
   import rx.functions.Func1;
   
   /**
    * Encapsulates a query parameter.
    */
   final class Parameter {
   
      private final String name;
      /**
       * Actual query parameter value to be encapsulated.
       */
      private final Object value;
  
      /**
       * Constructor.
       * 
       * @param parameter
       */
      Parameter(Object value) {
          this(null, value);
      }
  
      Parameter(String name, Object value) {
          this.name = name;
          this.value = value;
      }
  
      /**
       * Returns the parameter value.
       * 
       * @return
       */
      Object value() {
          return value;
      }
  
      boolean hasName() {
          return name != null;
      }
  
      String name() {
          return name;
      }
  
      @Override
      public String toString() {
          StringBuilder builder = new StringBuilder();
          builder.append("Parameter [value=");
          builder.append(value);
          builder.append("]");
          return builder.toString();
      }
  
      /**
       * A conversion function for use in Observable.map().
       */
      static final Func1<Object, Parameter> TO_PARAMETER = new Func1<Object, Parameter>() {
  
          @Override
          public Parameter call(Object parameter) {
              Conditions.checkFalse(parameter instanceof Parameter);
              return new Parameter(parameter);
          }
      };
  
  }