Method equals

fe/src/main/java/org/apache/impala/analysis/Expr.java:1043–1046

Returns true if two expressions are equal. The equality comparison works on analyzed as well as unanalyzed exprs by ignoring implicit casts. If overridden by a subclass, also provide an appropriate implementation for hashCode.

(Object obj)

   * also provide an appropriate implementation for hashCode.
   */
  @Override
  public final boolean equals(Object obj) {
    return obj instanceof Expr && matches((Expr) obj, SlotRef.SLOTREF_EQ_CMP);
  }

  /**
   * Local hash code that ignores children.