1 /*
   2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.nashorn.internal.ir;
  27 
  28 import java.io.Serializable;
  29 import java.util.List;
  30 import jdk.nashorn.internal.codegen.CompileUnit;
  31 
  32 /**
  33  * An interface for splittable expressions.
  34  */
  35 public interface Splittable {
  36 
  37     /**
  38      * Get a list of split ranges for this splittable expression, or null
  39      * if the expression should not be split.
  40      *
  41      * @return a list of split ranges
  42      */
  43     List<SplitRange> getSplitRanges();
  44 
  45     /**
  46      * A SplitRange is a range in a splittable expression. It defines the
  47      * boundaries of the split range and provides a compile unit for code generation.
  48      */
  49     final class SplitRange implements CompileUnitHolder, Serializable {
  50         private static final long serialVersionUID = 1L;
  51 
  52         /** Compile unit associated with the postsets range. */
  53         private final CompileUnit compileUnit;
  54 
  55         /** postsets range associated with the unit (hi not inclusive). */
  56         private final int low, high;
  57 
  58         /**
  59          * Constructor
  60          * @param compileUnit compile unit
  61          * @param low lowest array index in unit
  62          * @param high highest array index in unit + 1
  63          */
  64         public SplitRange(final CompileUnit compileUnit, final int low, final int high) {
  65             this.compileUnit = compileUnit;
  66             this.low   = low;
  67             this.high   = high;
  68         }
  69 
  70         /**
  71          * Get the high index position of the ArrayUnit (exclusive)
  72          * @return high index position
  73          */
  74         public int getHigh() {
  75             return high;
  76         }
  77 
  78         /**
  79          * Get the low index position of the ArrayUnit (inclusive)
  80          * @return low index position
  81          */
  82         public int getLow() {
  83             return low;
  84         }
  85 
  86         /**
  87          * The array compile unit
  88          * @return array compile unit
  89          */
  90         @Override
  91         public CompileUnit getCompileUnit() {
  92             return compileUnit;
  93         }
  94     }
  95 }