org.apache.sysds.lops.compile

## Class LopComparator<N extends Lop>

- java.lang.Object
- - org.apache.sysds.lops.compile.LopComparator<N>

- Type Parameters:
    `N` - class extending Lop
  All Implemented Interfaces:
    Comparator<N>

      public class LopComparator<N extends Lop>
      extends Object
      implements Comparator<N>

  Comparator class used in sorting the LopDAG in topological order. Refer to doTopologicalSort_strict_order() in dml/lops/compile/Dag.java Topological sort guarantees the following: 1) All lops with level i appear before any lop with level greater than i (source nodes are at level 0) 2) Within a given level, nodes are ordered by their ID i.e., by the other in which they are created compare() method is designed to respect the above two requirements.

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `LopComparator()`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `int` | `compare(N o1, N o2)`

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

    - ### Methods inherited from interface java.util.Comparator

      `comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong`

- - ### Constructor Detail

    - #### LopComparator

          public LopComparator()

  - ### Method Detail

    - #### compare

          public int compare(N o1,
                             N o2)

      Specified by:
        `compare` in interface `Comparator<N extends Lop>`

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