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1   package org.djunits.quantity;
2   
3   import java.util.Locale;
4   
5   import org.djunits.quantity.def.Quantity;
6   import org.djunits.unit.si.SIUnit;
7   import org.djutils.base.NumberParser;
8   import org.djutils.exceptions.Throw;
9   
10  /**
11   * SI quantity, with arbitrary SI unit. The class has <code>as...</code> methods such as <code>asDuration(...)</code>, which
12   * will succeed if the SI unit of the quantity is a duration unit, i.e., 's'.
13   * <p>
14   * Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
15   * for project information <a href="https://djunits.org" target="_blank">https://djunits.org</a>. The DJUNITS project is
16   * distributed under a <a href="https://djunits.org/docs/license.html" target="_blank">three-clause BSD-style license</a>.
17   * @author Alexander Verbraeck
18   */
19  public class SIQuantity extends Quantity<SIQuantity>
20  {
21      /** */
22      private static final long serialVersionUID = 600L;
23  
24      /**
25       * Instantiate a SI quantity with a unit.
26       * @param valueInUnit the value, expressed in the unit
27       * @param unit the unit in which the value is expressed
28       */
29      public SIQuantity(final double valueInUnit, final SIUnit unit)
30      {
31          super(valueInUnit, unit);
32      }
33  
34      /**
35       * Instantiate a SI quantity with a unit, expressed as a String.
36       * @param valueInUnit the value, expressed in the unit
37       * @param abbreviation the String abbreviation of the unit in which the value is expressed
38       */
39      public SIQuantity(final double valueInUnit, final String abbreviation)
40      {
41          this(valueInUnit, SIUnit.of(abbreviation));
42      }
43  
44      /**
45       * Construct SI quantity.
46       * @param value Scalar from which to construct this instance
47       */
48      public SIQuantity(final SIQuantity value)
49      {
50          super(value.si(), value.getDisplayUnit());
51      }
52  
53      @Override
54      public SIQuantity instantiateSi(final double si)
55      {
56          return new SIQuantity(si, getDisplayUnit());
57      }
58  
59      @Override
60      public SIUnit getDisplayUnit()
61      {
62          return (SIUnit) super.getDisplayUnit();
63      }
64  
65      @Override
66      public SIUnit siUnit()
67      {
68          return getDisplayUnit();
69      }
70  
71      /**
72       * Returns an SI quantity representation of a textual representation of a value with a unit. The String representation that
73       * can be parsed is the double value in the unit, followed by a localized or English abbreviation of the unit. Spaces are
74       * allowed, but not required, between the value and the unit.
75       * @param text the textual representation to parse into a SI
76       * @return the Scalar representation of the value in its unit
77       * @throws IllegalArgumentException when the text cannot be parsed
78       * @throws NullPointerException when the text argument is null
79       */
80      public static SIQuantity valueOf(final String text)
81      {
82          Throw.whenNull(text, "Error parsing SI quantity: text to parse is null");
83          Throw.when(text.length() == 0, IllegalArgumentException.class, "Error parsing SI quantity: empty text to parse");
84          try
85          {
86              NumberParser numberParser = new NumberParser().lenient().trailing();
87              double d = numberParser.parseDouble(text);
88              String unitString = text.substring(numberParser.getTrailingPosition()).trim();
89              SIUnit unit = SIUnit.of(unitString);
90              return new SIQuantity(d, unit);
91          }
92          catch (Exception exception)
93          {
94              throw new IllegalArgumentException(
95                      "Error parsing SI quantity from " + text + " using Locale " + Locale.getDefault(Locale.Category.FORMAT),
96                      exception);
97          }
98      }
99  
100     /**
101      * Returns an SI quantity based on a value and the textual representation of the unit, which can be localized.
102      * @param valueInUnit the value, expressed in the unit as given by unitString
103      * @param unitString the textual representation of the unit
104      * @return the Scalar representation of the value in its unit
105      * @throws IllegalArgumentException when the unit cannot be parsed or is incorrect
106      * @throws NullPointerException when the unitString argument is null
107      */
108     public static SIQuantity of(final double valueInUnit, final String unitString)
109     {
110         Throw.whenNull(unitString, "Error parsing SI quantity: unitString is null");
111         Throw.when(unitString.length() == 0, IllegalArgumentException.class, "Error parsing SI quantity: empty unitString");
112         SIUnit unit = SIUnit.of(unitString);
113         return new SIQuantity(valueInUnit, unit);
114     }
115 
116 }