[Backport 2.x] Updated EXPM1() and Tests to New Engine

core/src/main/java/org/opensearch/sql/expression/DSL.java

@@ -174,6 +174,10 @@ public static FunctionExpression exp(Expression... expressions) {
     return compile(FunctionProperties.None, BuiltinFunctionName.EXP, expressions);
   }
 
+  public static FunctionExpression expm1(Expression... expressions) {
+    return compile(FunctionProperties.None, BuiltinFunctionName.EXPM1, expressions);
+  }
+
   public static FunctionExpression floor(Expression... expressions) {
     return compile(FunctionProperties.None, BuiltinFunctionName.FLOOR, expressions);
   }

core/src/main/java/org/opensearch/sql/expression/function/BuiltinFunctionName.java

@@ -28,6 +28,7 @@ public enum BuiltinFunctionName {
   CRC32(FunctionName.of("crc32")),
   E(FunctionName.of("e")),
   EXP(FunctionName.of("exp")),
+  EXPM1(FunctionName.of("expm1")),
   FLOOR(FunctionName.of("floor")),
   LN(FunctionName.of("ln")),
   LOG(FunctionName.of("log")),

core/src/main/java/org/opensearch/sql/expression/operator/arthmetic/MathematicalFunction.java

@@ -32,6 +32,7 @@
 import org.opensearch.sql.data.model.ExprNullValue;
 import org.opensearch.sql.data.model.ExprShortValue;
 import org.opensearch.sql.data.model.ExprStringValue;
+import org.opensearch.sql.data.model.ExprValue;
 import org.opensearch.sql.data.type.ExprCoreType;
 import org.opensearch.sql.data.type.ExprType;
 import org.opensearch.sql.expression.function.BuiltinFunctionName;
@@ -59,6 +60,7 @@ public static void register(BuiltinFunctionRepository repository) {
     repository.register(crc32());
     repository.register(euler());
     repository.register(exp());
+    repository.register(expm1());
     repository.register(floor());
     repository.register(ln());
     repository.register(log());
@@ -85,6 +87,23 @@ public static void register(BuiltinFunctionRepository repository) {
     repository.register(tan());
   }
 
+  /**
+   * Base function for math functions with similar formats that return DOUBLE.
+   *
+   * @param functionName BuiltinFunctionName of math function.
+   * @param formula lambda function of math formula.
+   * @param returnType data type return type of the calling function
+   * @return DefaultFunctionResolver for math functions.
+   */
+  private static DefaultFunctionResolver baseMathFunction(
+          FunctionName functionName, SerializableFunction<ExprValue,
+          ExprValue> formula, ExprCoreType returnType) {
+    return FunctionDSL.define(functionName,
+        ExprCoreType.numberTypes().stream().map(type -> FunctionDSL.impl(
+                    FunctionDSL.nullMissingHandling(formula),
+                    returnType, type)).collect(Collectors.toList()));
+  }
+
   /**
    * Definition of abs() function. The supported signature of abs() function are INT -> INT LONG ->
    * LONG FLOAT -> FLOAT DOUBLE -> DOUBLE
@@ -186,15 +205,21 @@ private static DefaultFunctionResolver euler() {
   }
 
   /**
-   * Definition of exp(x) function. Calculate exponent function e to the x The supported signature
-   * of exp function is INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
+   * Definition of exp(x) function. Calculate exponent function e to the x
+   * The supported signature of exp function is INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver exp() {
-    return FunctionDSL.define(BuiltinFunctionName.EXP.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprDoubleValue(Math.exp(v.doubleValue()))),
-                type, DOUBLE)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.EXP.getName(),
+            v -> new ExprDoubleValue(Math.exp(v.doubleValue())), DOUBLE);
+  }
+
+  /**
+   * Definition of expm1(x) function. Calculate exponent function e to the x, minus 1
+   * The supported signature of exp function is INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
+   */
+  private static DefaultFunctionResolver expm1() {
+    return baseMathFunction(BuiltinFunctionName.EXPM1.getName(),
+            v -> new ExprDoubleValue(Math.expm1(v.doubleValue())), DOUBLE);
   }
 
   /**
@@ -214,11 +239,8 @@ private static DefaultFunctionResolver floor() {
    * ln function is INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver ln() {
-    return FunctionDSL.define(BuiltinFunctionName.LN.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprDoubleValue(Math.log(v.doubleValue()))),
-                type, DOUBLE)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.LN.getName(),
+            v -> new ExprDoubleValue(Math.log(v.doubleValue())), DOUBLE);
   }
 
   /**
@@ -255,23 +277,17 @@ private static DefaultFunctionResolver log() {
    * log function is SHORT/INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver log10() {
-    return FunctionDSL.define(BuiltinFunctionName.LOG10.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprDoubleValue(Math.log10(v.doubleValue()))),
-                type, DOUBLE)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.LOG10.getName(),
+            v -> new ExprDoubleValue(Math.log10(v.doubleValue())), DOUBLE);
   }
 
   /**
    * Definition of log2(x) function. Calculate base-2 logarithm of x The supported signature of log
    * function is SHORT/INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver log2() {
-    return FunctionDSL.define(BuiltinFunctionName.LOG2.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprDoubleValue(Math.log(v.doubleValue()) / Math.log(2))), DOUBLE, type))
-            .collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.LOG2.getName(),
+            v -> new ExprDoubleValue(Math.log(v.doubleValue()) / Math.log(2)), DOUBLE);
   }
 
   /**
@@ -450,11 +466,8 @@ private static DefaultFunctionResolver round() {
    * SHORT/INTEGER/LONG/FLOAT/DOUBLE -> INTEGER
    */
   private static DefaultFunctionResolver sign() {
-    return FunctionDSL.define(BuiltinFunctionName.SIGN.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprIntegerValue(Math.signum(v.doubleValue()))),
-                INTEGER, type)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.SIGN.getName(),
+            v -> new ExprIntegerValue(Math.signum(v.doubleValue())), INTEGER);
   }
 
   /**
@@ -464,12 +477,9 @@ private static DefaultFunctionResolver sign() {
    * INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver sqrt() {
-    return FunctionDSL.define(BuiltinFunctionName.SQRT.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> v.doubleValue() < 0 ? ExprNullValue.of() :
-                    new ExprDoubleValue(Math.sqrt(v.doubleValue()))),
-                DOUBLE, type)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.SQRT.getName(),
+            v -> v.doubleValue() < 0 ? ExprNullValue.of() :
+                    new ExprDoubleValue(Math.sqrt(v.doubleValue())), DOUBLE);
   }
 
   /**
@@ -479,11 +489,8 @@ private static DefaultFunctionResolver sqrt() {
    * INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver cbrt() {
-    return FunctionDSL.define(BuiltinFunctionName.CBRT.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprDoubleValue(Math.cbrt(v.doubleValue()))),
-                DOUBLE, type)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.CBRT.getName(),
+            v -> new ExprDoubleValue(Math.cbrt(v.doubleValue())), DOUBLE);
   }
 
   /**
@@ -606,11 +613,8 @@ private static DefaultFunctionResolver atan2() {
    * INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver cos() {
-    return FunctionDSL.define(BuiltinFunctionName.COS.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprDoubleValue(Math.cos(v.doubleValue()))),
-                DOUBLE, type)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.COS.getName(),
+            v -> new ExprDoubleValue(Math.cos(v.doubleValue())), DOUBLE);
   }
 
   /**
@@ -641,11 +645,8 @@ private static DefaultFunctionResolver cot() {
    * INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver degrees() {
-    return FunctionDSL.define(BuiltinFunctionName.DEGREES.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprDoubleValue(Math.toDegrees(v.doubleValue()))),
-                type, DOUBLE)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.DEGREES.getName(),
+            v -> new ExprDoubleValue(Math.toDegrees(v.doubleValue())), DOUBLE);
   }
 
   /**
@@ -655,11 +656,8 @@ private static DefaultFunctionResolver degrees() {
    * INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver radians() {
-    return FunctionDSL.define(BuiltinFunctionName.RADIANS.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprDoubleValue(Math.toRadians(v.doubleValue()))),
-                DOUBLE, type)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.RADIANS.getName(),
+            v -> new ExprDoubleValue(Math.toRadians(v.doubleValue())), DOUBLE);
   }
 
   /**
@@ -669,11 +667,8 @@ private static DefaultFunctionResolver radians() {
    * INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver sin() {
-    return FunctionDSL.define(BuiltinFunctionName.SIN.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprDoubleValue(Math.sin(v.doubleValue()))),
-                DOUBLE, type)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.SIN.getName(),
+            v -> new ExprDoubleValue(Math.sin(v.doubleValue())), DOUBLE);
   }
 
   /**
@@ -683,10 +678,7 @@ private static DefaultFunctionResolver sin() {
    * INTEGER/LONG/FLOAT/DOUBLE -> DOUBLE
    */
   private static DefaultFunctionResolver tan() {
-    return FunctionDSL.define(BuiltinFunctionName.TAN.getName(),
-        ExprCoreType.numberTypes().stream()
-            .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling(
-                v -> new ExprDoubleValue(Math.tan(v.doubleValue()))),
-                DOUBLE, type)).collect(Collectors.toList()));
+    return baseMathFunction(BuiltinFunctionName.TAN.getName(),
+            v -> new ExprDoubleValue(Math.tan(v.doubleValue())), DOUBLE);
   }
 }

core/src/test/java/org/opensearch/sql/expression/operator/arthmetic/MathematicalFunctionTest.java

@@ -565,6 +565,90 @@ public void exp_missing_value() {
     assertTrue(exp.valueOf(valueEnv()).isMissing());
   }
 
+  /**
+   * Test expm1 with integer value.
+   */
+  @ParameterizedTest(name = "expm1({0})")
+  @ValueSource(ints = {
+      -1, 0, 1, Integer.MAX_VALUE, Integer.MIN_VALUE})
+  public void expm1_int_value(Integer value) {
+    FunctionExpression expm1 = DSL.expm1(DSL.literal(value));
+    assertThat(
+            expm1.valueOf(valueEnv()),
+            allOf(hasType(DOUBLE), hasValue(Math.expm1(value))));
+    assertEquals(String.format("expm1(%s)", value), expm1.toString());
+  }
+
+  /**
+   * Test expm1 with long value.
+   */
+  @ParameterizedTest(name = "expm1({0})")
+  @ValueSource(longs = {
+      -1L, 0L, 1L, Long.MAX_VALUE, Long.MIN_VALUE})
+  public void expm1_long_value(Long value) {
+    FunctionExpression expm1 = DSL.expm1(DSL.literal(value));
+    assertThat(
+            expm1.valueOf(valueEnv()),
+            allOf(hasType(DOUBLE), hasValue(Math.expm1(value))));
+    assertEquals(String.format("expm1(%s)", value), expm1.toString());
+  }
+
+  /**
+   * Test expm1 with float value.
+   */
+  @ParameterizedTest(name = "expm1({0})")
+  @ValueSource(floats = {
+      -1.5F, -1F, 0F, 1F, 1.5F, Float.MAX_VALUE, Float.MIN_VALUE})
+  public void expm1_float_value(Float value) {
+    FunctionExpression expm1 = DSL.expm1(DSL.literal(value));
+    assertThat(
+            expm1.valueOf(valueEnv()),
+            allOf(hasType(DOUBLE), hasValue(Math.expm1(value))));
+    assertEquals(String.format("expm1(%s)", value), expm1.toString());
+  }
+
+  /**
+   * Test expm1 with double value.
+   */
+  @ParameterizedTest(name = "expm1({0})")
+  @ValueSource(doubles = {
+      -1.5D, -1D, 0D, 1D, 1.5D, Double.MAX_VALUE, Double.MIN_VALUE})
+  public void expm1_double_value(Double value) {
+    FunctionExpression expm1 = DSL.expm1(DSL.literal(value));
+    assertThat(
+            expm1.valueOf(valueEnv()),
+            allOf(hasType(DOUBLE), hasValue(Math.expm1(value))));
+    assertEquals(String.format("expm1(%s)", value), expm1.toString());
+  }
+
+  /**
+   * Test expm1 with short value.
+   */
+  @ParameterizedTest(name = "expm1({0})")
+  @ValueSource(shorts = {
+      -1, 0, 1, Short.MAX_VALUE, Short.MIN_VALUE})
+  public void expm1_short_value(Short value) {
+    FunctionExpression expm1 = DSL.expm1(DSL.literal(value));
+    assertThat(
+            expm1.valueOf(valueEnv()),
+            allOf(hasType(DOUBLE), hasValue(Math.expm1(value))));
+    assertEquals(String.format("expm1(%s)", value), expm1.toString());
+  }
+
+  /**
+   * Test expm1 with short value.
+   */
+  @ParameterizedTest(name = "expm1({0})")
+  @ValueSource(bytes = {
+      -1, 0, 1, Byte.MAX_VALUE, Byte.MIN_VALUE})
+  public void expm1_byte_value(Byte value) {
+    FunctionExpression expm1 = DSL.expm1(DSL.literal(value));
+    assertThat(
+            expm1.valueOf(valueEnv()),
+            allOf(hasType(DOUBLE), hasValue(Math.expm1(value))));
+    assertEquals(String.format("expm1(%s)", value), expm1.toString());
+  }
+
   /**
    * Test floor with integer value.
    */
@@ -575,7 +659,7 @@ public void floor_int_value(Integer value) {
     assertThat(
         floor.valueOf(valueEnv()),
         allOf(hasType(LONG), hasValue((long) Math.floor(value))));
-    assertEquals(String.format("floor(%s)", value.toString()), floor.toString());
+    assertEquals(String.format("floor(%s)", value), floor.toString());
   }
 
   /**

docs/user/dql/functions.rst

@@ -443,10 +443,21 @@ EXPM1
 Description
 >>>>>>>>>>>
 
-Specifications:
+Usage: EXPM1(NUMBER T) returns the exponential of T, minus 1.
+
+Argument type: INTEGER/LONG/FLOAT/DOUBLE
 
-1. EXPM1(NUMBER T) -> T
+Return type: DOUBLE
 
+Example::
+
+    os> SELECT EXPM1(-1), EXPM1(0), EXPM1(1), EXPM1(1.5)
+    fetched rows / total rows = 1/1
+    +---------------------+------------+-------------------+-------------------+
+    | EXPM1(-1)           | EXPM1(0)   | EXPM1(1)          | EXPM1(1.5)        |
+    |---------------------+------------+-------------------+-------------------|
+    | -0.6321205588285577 | 0.0        | 1.718281828459045 | 3.481689070338065 |
+    +---------------------+------------+-------------------+-------------------+
 
 FLOOR
 -----

docs/user/ppl/functions/math.rst

@@ -187,6 +187,7 @@ Example::
     | c                    | 44                   | 1100              | 15                  |
     +----------------------+----------------------+-------------------+---------------------+
 
+
 COS
 ---
 
@@ -278,6 +279,7 @@ Example::
     | 89.95437383553924 |
     +-------------------+
 
+
 E
 -
 
@@ -309,7 +311,7 @@ Usage: exp(x) return e raised to the power of x.
 
 Argument type: INTEGER/LONG/FLOAT/DOUBLE
 
-Return type: INTEGER
+Return type: DOUBLE
 
 Example::