tighten up array handling, fix bug with array_slice output type inference

core/src/main/java/org/apache/druid/math/expr/ApplyFunction.java

@@ -407,7 +407,7 @@ public ExprEval apply(LambdaExpr lambdaExpr, List<Expr> argsExpr, Expr.ObjectBin
         return ExprEval.of(null);
       }
       if (hadEmpty) {
-        return ExprEval.ofStringArray(new String[0]);
+        return ExprEval.ofStringArray(new Object[0]);
       }
       Expr accExpr = argsExpr.get(argsExpr.size() - 1);
 
@@ -576,9 +576,12 @@ public String name()
     @Override
     public ExprEval match(Object[] values, LambdaExpr expr, SettableLambdaBinding bindings)
     {
-      boolean anyMatch = Arrays.stream(values)
-                               .anyMatch(o -> expr.eval(bindings.withBinding(expr.getIdentifier(), o)).asBoolean());
-      return ExprEval.ofLongBoolean(anyMatch);
+      for (Object o : values) {
+        if (expr.eval(bindings.withBinding(expr.getIdentifier(), o)).asBoolean()) {
+          return ExprEval.ofLongBoolean(true);
+        }
+      }
+      return ExprEval.ofLongBoolean(false);
     }
   }
 
@@ -599,9 +602,12 @@ public String name()
     @Override
     public ExprEval match(Object[] values, LambdaExpr expr, SettableLambdaBinding bindings)
     {
-      boolean allMatch = Arrays.stream(values)
-                               .allMatch(o -> expr.eval(bindings.withBinding(expr.getIdentifier(), o)).asBoolean());
-      return ExprEval.ofLongBoolean(allMatch);
+      for (Object o : values) {
+        if (!expr.eval(bindings.withBinding(expr.getIdentifier(), o)).asBoolean()) {
+          return ExprEval.ofLongBoolean(false);
+        }
+      }
+      return ExprEval.ofLongBoolean(true);
     }
   }
 

core/src/main/java/org/apache/druid/math/expr/Evals.java

@@ -20,7 +20,6 @@
 package org.apache.druid.math.expr;
 
 import org.apache.druid.common.config.NullHandling;
-import org.apache.druid.java.util.common.logger.Logger;
 
 import javax.annotation.Nullable;
 import java.util.Arrays;
@@ -30,8 +29,6 @@
  */
 public class Evals
 {
-  private static final Logger log = new Logger(Evals.class);
-
   public static boolean isAllConstants(Expr... exprs)
   {
     return isAllConstants(Arrays.asList(exprs));
@@ -71,4 +68,16 @@ public static boolean asBoolean(@Nullable String x)
   {
     return !NullHandling.isNullOrEquivalent(x) && Boolean.parseBoolean(x);
   }
+
+  /**
+   * Call {@link Object#toString()} on a non-null value
+   */
+  @Nullable
+  public static String asString(@Nullable Object o)
+  {
+    if (o == null) {
+      return null;
+    }
+    return o.toString();
+  }
 }