refactor!: modify C implementation to accept double instead of int32 in math/base/special/bernoulli

This commit updates the signature of the C API to accept a double rather than int32. The rationale was so that users get the same results/behavior in both JavaScript and C. This arose in the context of ufuncs, where the diverging type signatures meant differences in what dtypes would be permissible. Instead, we decided to unify and ensure the behavior is consistent.

BREAKING CHANGE: update signature to accept doubles

User code should behave similarly in the primary case of providing integer-valued input values. However, no longer will real-values truncate. Now, real-valued inputs will result in `NaN`, which is, arguably, better behavior, as real-to-integer truncation can be a source of silent bugs.

PR-URL: #7940
Co-authored-by: Athan Reines <[email protected]>
Reviewed-by: Athan Reines <[email protected]>

Author: gunjjoshi

lib/node_modules/@stdlib/math/base/special/bernoulli/README.md

@@ -154,19 +154,19 @@ for ( i = 0; i < 280; i++ ) {
 Computes the nth [Bernoulli number][bernoulli-number].
 
 ```c
-double out = stdlib_base_bernoulli( 0 );
+double out = stdlib_base_bernoulli( 0.0 );
 // returns 1.0
 
-out = stdlib_base_bernoulli( 1 );
+out = stdlib_base_bernoulli( 1.0 );
 // returns 0.5
 ```
 
 The function accepts the following arguments:
 
--   **n**: `[in] int32_t` input value.
+-   **n**: `[in] double` input value.
 
 ```c
-double stdlib_base_bernoulli( const int32_t n );
+double stdlib_base_bernoulli( const double n );
 ```
 
 </section>
@@ -190,15 +190,14 @@ double stdlib_base_bernoulli( const int32_t n );
 ```c
 #include "stdlib/math/base/special/bernoulli.h"
 #include <stdio.h>
-#include <stdint.h>
 
 int main( void ) {
-    int32_t i;
+    double i;
     double v;
 
-    for ( i = 0; i < 130; i++ ) {
+    for ( i = 0.0; i < 130.0; i++ ) {
         v = stdlib_base_bernoulli( i );
-        printf( "bernoulli(%d) = %lf\n", i, v );
+        printf( "bernoulli(%lf) = %lf\n", i, v );
     }
 }
 ```

lib/node_modules/@stdlib/math/base/special/bernoulli/benchmark/c/native/benchmark.c

@@ -102,7 +102,7 @@ static double benchmark( void ) {
 
 	t = tic();
 	for ( i = 0; i < ITERATIONS; i++ ) {
-		y = stdlib_base_bernoulli( (int)( x[ i % 100 ] ) );
+		y = stdlib_base_bernoulli( ( x[ i % 100 ] ) );
 		if ( y != y ) {
 			printf( "should not return NaN\n" );
 			break;

lib/node_modules/@stdlib/math/base/special/bernoulli/examples/c/example.c

@@ -18,14 +18,13 @@
 
 #include "stdlib/math/base/special/bernoulli.h"
 #include <stdio.h>
-#include <stdint.h>
 
 int main( void ) {
-	int32_t i;
+	double i;
 	double v;
 
-	for ( i = 0; i < 130; i++ ) {
+	for ( i = 0.0; i < 130.0; i++ ) {
 		v = stdlib_base_bernoulli( i );
-		printf( "bernoulli(%d) = %lf\n", i, v );
+		printf( "bernoulli(%lf) = %lf\n", i, v );
 	}
 }

lib/node_modules/@stdlib/math/base/special/bernoulli/include/stdlib/math/base/special/bernoulli.h

@@ -19,8 +19,6 @@
 #ifndef STDLIB_MATH_BASE_SPECIAL_BERNOULLI_H
 #define STDLIB_MATH_BASE_SPECIAL_BERNOULLI_H
 
-#include <stdint.h>
-
 /*
 * If C++, prevent name mangling so that the compiler emits a binary file having undecorated names, thus mirroring the behavior of a C compiler.
 */
@@ -31,7 +29,7 @@ extern "C" {
 /**
 * Computes the nth Bernoulli number.
 */
-double stdlib_base_bernoulli( const int32_t n );
+double stdlib_base_bernoulli( const double n );
 
 #ifdef __cplusplus
 }

lib/node_modules/@stdlib/math/base/special/bernoulli/lib/main.js

@@ -92,7 +92,7 @@ function bernoulli( n ) {
 		return 0.0;
 	}
 	if ( n > MAX_BERNOULLI ) {
-		return ( (n/2)&1 ) ? PINF : NINF;
+		return ( isOdd( n/2.0 ) ) ? PINF : NINF;
 	}
 	return BERNOULLI[ n/2 ];
 }

lib/node_modules/@stdlib/math/base/special/bernoulli/manifest.json

@@ -39,7 +39,8 @@
         "@stdlib/math/base/napi/unary",
         "@stdlib/math/base/assert/is-odd",
         "@stdlib/constants/float64/ninf",
-        "@stdlib/constants/float64/pinf"
+        "@stdlib/constants/float64/pinf",
+        "@stdlib/math/base/assert/is-nonnegative-integer"
       ]
     },
     {
@@ -55,7 +56,8 @@
       "dependencies": [
         "@stdlib/math/base/assert/is-odd",
         "@stdlib/constants/float64/ninf",
-        "@stdlib/constants/float64/pinf"
+        "@stdlib/constants/float64/pinf",
+        "@stdlib/math/base/assert/is-nonnegative-integer"
       ]
     },
     {
@@ -71,7 +73,8 @@
       "dependencies": [
         "@stdlib/math/base/assert/is-odd",
         "@stdlib/constants/float64/ninf",
-        "@stdlib/constants/float64/pinf"
+        "@stdlib/constants/float64/pinf",
+        "@stdlib/math/base/assert/is-nonnegative-integer"
       ]
     }
   ]

lib/node_modules/@stdlib/math/base/special/bernoulli/src/addon.c

@@ -19,4 +19,4 @@
 #include "stdlib/math/base/special/bernoulli.h"
 #include "stdlib/math/base/napi/unary.h"
 
-STDLIB_MATH_BASE_NAPI_MODULE_I_D( stdlib_base_bernoulli )
+STDLIB_MATH_BASE_NAPI_MODULE_D_D( stdlib_base_bernoulli )

lib/node_modules/@stdlib/math/base/special/bernoulli/src/main.c

@@ -16,10 +16,13 @@
 * limitations under the License.
 */
 
+#include "stdlib/math/base/assert/is_nonnegative_integer.h"
 #include "stdlib/math/base/assert/is_odd.h"
 #include "stdlib/constants/float64/ninf.h"
 #include "stdlib/constants/float64/pinf.h"
 #include "stdlib/math/base/special/bernoulli.h"
+#include <stdint.h>
+#include <stdlib.h>
 
 static const double bernoulli_value[ 130 ] = {
 	1.00000000000000000000000000000000000000000,
@@ -164,21 +167,21 @@ int32_t MAX_BERNOULLI = 258;
 * @return     output value
 *
 * @example
-* double out = stdlib_base_bernoulli( 0 );
-* // returns 1
+* double out = stdlib_base_bernoulli( 0.0 );
+* // returns 1.0
 */
-double stdlib_base_bernoulli( const int32_t n ) {
-	if ( n < 0 ) {
+double stdlib_base_bernoulli( const double n ) {
+	if ( !stdlib_base_is_nonnegative_integer( n ) ) {
 		return 0.0 / 0.0; // NaN
 	}
-	if ( n == 1 ) {
+	if ( n == 1.0 ) {
 		return 0.5;
 	}
 	if ( stdlib_base_is_odd( n ) ) {
 		return 0.0;
 	}
 	if ( n > MAX_BERNOULLI ) {
-		return ( ( n / 2 ) & 1 ) ? STDLIB_CONSTANT_FLOAT64_PINF : STDLIB_CONSTANT_FLOAT64_NINF;
+		return ( stdlib_base_is_odd( n/2.0 ) ) ? STDLIB_CONSTANT_FLOAT64_PINF : STDLIB_CONSTANT_FLOAT64_NINF;
 	}
-	return bernoulli_value[ n / 2 ];
+	return bernoulli_value[ (size_t)( n / 2.0 ) ];
 }