fix: built-in function: support radians() function #788

hybridse/src/codegen/udf_ir_builder_test.cc

@@ -1007,6 +1007,13 @@ TEST_F(UdfIRBuilderTest, degrees) {
     CheckUdf<double, double>(udf_name, -90.0, -pi/2);
     CheckUdf<Nullable<double>, Nullable<double>>(udf_name, nullptr, nullptr);
 }
+TEST_F(UdfIRBuilderTest, degree_to_radius_check) {
+    auto udf_name = "radians";
+    CheckUdf<double, double>(udf_name, 3.141592653589793238463, 180);
+    CheckUdf<double, double>(udf_name, 1.570796326794896619231, 90);
+    CheckUdf<double, double>(udf_name, 0, 0);
+    CheckUdf<Nullable<double>, Nullable<double>>(udf_name, nullptr, nullptr);
+}
 }  // namespace codegen
 }  // namespace hybridse
 

hybridse/src/udf/default_udf_library.cc

@@ -1286,6 +1286,19 @@ void DefaultUdfLibrary::InitMathUdf() {
             @param expr
 
             @since 0.5.0)");
+    RegisterExternal("RADIANS")
+        .args<double>(
+            static_cast<double (*)(double)>(udf::v1::degree_to_radius))
+        .doc(R"(
+            @brief Returns the argument X, converted from degrees to radians. (Note that π radians equals 180 degrees.)
+
+            Example:
+
+            @code{.sql}
+                SELECT RADIANS(90);
+                --output 1.570796326794896619231
+            @endcode
+            @since 0.6.0)");
     InitTrigonometricUdf();
 }
 

hybridse/src/udf/udf.cc

@@ -159,7 +159,11 @@ int32_t weekofyear(Date *date) {
 
 float Cotf(float x) { return cosf(x) / sinf(x); }
 
-double Degrees(double x) { return x * (180 / 3.141592653589793238463L); }
+double degree_to_radius(double degree) {
+    return degree/180.0L*M_PI;
+}
+
+double Degrees(double x) { return x * (180 / M_PI); }
 
 void date_format(Timestamp *timestamp,
                  StringRef *format,

hybridse/src/udf/udf.h

@@ -224,6 +224,8 @@ int32_t weekofyear(int64_t ts);
 int32_t weekofyear(Timestamp *ts);
 int32_t weekofyear(Date *ts);
 
+double degree_to_radius(double degree);
+
 float Cotf(float x);
 double Degrees(double x);