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

This commit updates the signature of the C API to accept a float 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 floats

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: #8032
Co-authored-by: Athan Reines <[email protected]>
Reviewed-by: Athan Reines <[email protected]>

Author: gunjjoshi

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

@@ -164,19 +164,19 @@ logEachMap( 'tribonaccif(%d) = %0.4f', v, tribonaccif );
 Computes the nth [Tribonacci number][tribonacci-number] as a [single-precision floating-point number][ieee754].
 
 ```c
-float out = stdlib_base_tribonaccif( 0 );
+float out = stdlib_base_tribonaccif( 0.0f );
 // returns 0.0f
 
-out = stdlib_base_tribonaccif( 4 );
+out = stdlib_base_tribonaccif( 4.0f );
 // returns 2.0f
 ```
 
 The function accepts the following arguments:
 
--   **n**: `[in] int32_t` input value.
+-   **n**: `[in] float` input value.
 
 ```c
-float stdlib_base_tribonaccif( const int32_t n );
+float stdlib_base_tribonaccif( const float n );
 ```
 
 </section>
@@ -200,15 +200,14 @@ float stdlib_base_tribonaccif( const int32_t n );
 ```c
 #include "stdlib/math/base/special/tribonaccif.h"
 #include <stdio.h>
-#include <stdint.h>
 
 int main( void ) {
-    int32_t i;
+    float i;
     float v;
 
-    for ( i = 0; i < 31; i++ ) {
+    for ( i = 0.0f; i < 31.0f; i++ ) {
         v = stdlib_base_tribonaccif( i );
-        printf( "tribonaccif(%d) = %f\n", i, v );
+        printf( "tribonaccif(%f) = %f\n", i, v );
     }
 }
 ```

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

@@ -91,14 +91,14 @@ static float rand_float( void ) {
 * @return elapsed time in seconds
 */
 static double benchmark( void ) {
-	int32_t x[ 100 ];
+	float x[ 100 ];
 	double elapsed;
 	double t;
 	float y;
 	int i;
 
 	for ( i = 0; i < 100; i++ ) {
-		x[ i ] = (int32_t)floorf( 40.0f*rand_float() );
+		x[ i ] = floorf( 40.0f*rand_float() );
 	}
 
 	t = tic();

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

@@ -18,14 +18,13 @@
 
 #include "stdlib/math/base/special/tribonaccif.h"
 #include <stdio.h>
-#include <stdint.h>
 
 int main( void ) {
-	int32_t i;
+	float i;
 	float v;
 
-	for ( i = 0; i < 31; i++ ) {
+	for ( i = 0.0f; i < 31.0f; i++ ) {
 		v = stdlib_base_tribonaccif( i );
-		printf( "tribonaccif(%d) = %f\n", i, v );
+		printf( "tribonaccif(%f) = %f\n", i, v );
 	}
 }

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

@@ -19,16 +19,14 @@
 #ifndef STDLIB_MATH_BASE_SPECIAL_TRIBONACCIF_H
 #define STDLIB_MATH_BASE_SPECIAL_TRIBONACCIF_H
 
-#include <stdint.h>
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /**
 * Computes the nth Tribonacci number as a single-precision floating-point number.
 */
-float stdlib_base_tribonaccif( const int32_t n );
+float stdlib_base_tribonaccif( const float n );
 
 #ifdef __cplusplus
 };

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

@@ -21,7 +21,7 @@
 // MODULES //
 
 var isnanf = require( '@stdlib/math/base/assert/is-nanf' );
-var isIntegerf = require( '@stdlib/math/base/assert/is-integerf' );
+var isNonnegativeIntegerf = require( '@stdlib/math/base/assert/is-nonnegative-integerf' );
 var FLOAT32_MAX_SAFE_NTH_TRIBONACCI = require( '@stdlib/constants/float32/max-safe-nth-tribonacci' ); // eslint-disable-line id-length
 var TRIBONACCIF = require( './tribonaccif.json' );
 
@@ -77,8 +77,7 @@ var TRIBONACCIF = require( './tribonaccif.json' );
 function tribonaccif( n ) {
 	if (
 		isnanf( n ) ||
-		isIntegerf( n ) === false ||
-		n < 0 ||
+		!isNonnegativeIntegerf( n ) ||
 		n > FLOAT32_MAX_SAFE_NTH_TRIBONACCI
 	) {
 		return NaN;

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

@@ -37,7 +37,9 @@
       "libpath": [],
       "dependencies": [
         "@stdlib/math/base/napi/unary",
-        "@stdlib/constants/float32/max-safe-nth-tribonacci"
+        "@stdlib/constants/float32/max-safe-nth-tribonacci",
+        "@stdlib/math/base/assert/is-nonnegative-integerf",
+        "@stdlib/math/base/assert/is-nanf"
       ]
     },
     {
@@ -51,7 +53,9 @@
       "libraries": [],
       "libpath": [],
       "dependencies": [
-        "@stdlib/constants/float32/max-safe-nth-tribonacci"
+        "@stdlib/constants/float32/max-safe-nth-tribonacci",
+        "@stdlib/math/base/assert/is-nonnegative-integerf",
+        "@stdlib/math/base/assert/is-nanf"
       ]
     },
     {
@@ -65,7 +69,9 @@
       "libraries": [],
       "libpath": [],
       "dependencies": [
-        "@stdlib/constants/float32/max-safe-nth-tribonacci"
+        "@stdlib/constants/float32/max-safe-nth-tribonacci",
+        "@stdlib/math/base/assert/is-nonnegative-integerf",
+        "@stdlib/math/base/assert/is-nanf"
       ]
     }
   ]

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

@@ -19,4 +19,4 @@
 #include "stdlib/math/base/special/tribonaccif.h"
 #include "stdlib/math/base/napi/unary.h"
 
-STDLIB_MATH_BASE_NAPI_MODULE_I_F( stdlib_base_tribonaccif )
+STDLIB_MATH_BASE_NAPI_MODULE_F_F( stdlib_base_tribonaccif )

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

@@ -18,7 +18,10 @@
 
 #include "stdlib/math/base/special/tribonaccif.h"
 #include "stdlib/constants/float32/max_safe_nth_tribonacci.h"
+#include "stdlib/math/base/assert/is_nonnegative_integerf.h"
+#include "stdlib/math/base/assert/is_nanf.h"
 #include <stdint.h>
+#include <stdlib.h>
 
 static const int32_t tribonaccif_value[ 31 ] = {
 	0,
@@ -61,12 +64,12 @@ static const int32_t tribonaccif_value[ 31 ] = {
 * @return      output value
 *
 * @example
-* float out = stdlib_base_tribonaccif( 1 );
+* float out = stdlib_base_tribonaccif( 1.0f );
 * // returns 0.0f
 */
-float stdlib_base_tribonaccif( const int32_t n ) {
-	if ( n < 0 || n > STDLIB_CONSTANT_FLOAT32_MAX_SAFE_NTH_TRIBONACCI ) {
+float stdlib_base_tribonaccif( const float n ) {
+	if ( stdlib_base_is_nanf( n ) || !stdlib_base_is_nonnegative_integerf( n ) || n > STDLIB_CONSTANT_FLOAT32_MAX_SAFE_NTH_TRIBONACCI ) {
 		return 0.0f / 0.0f; // NaN
 	}
-	return tribonaccif_value[ n ];
+	return tribonaccif_value[ (size_t)n ];
 }

lib/node_modules/@stdlib/math/base/special/tribonaccif/test/test.native.js

@@ -23,6 +23,7 @@
 var resolve = require( 'path' ).resolve;
 var tape = require( 'tape' );
 var isnanf = require( '@stdlib/math/base/assert/is-nanf' );
+var PINF = require( '@stdlib/constants/float32/pinf' );
 var tryRequire = require( '@stdlib/utils/try-require' );
 
 
@@ -58,6 +59,24 @@ tape( 'if provided a negative number, the function returns `NaN`', opts, functio
 	t.end();
 });
 
+tape( 'if provided positive infinity, the function returns `NaN`', opts, function test( t ) {
+	var v = tribonaccif( PINF );
+	t.strictEqual( isnanf( v ), true, 'returns expected value' );
+	t.end();
+});
+
+tape( 'if provided `NaN`, the function returns `NaN`', opts, function test( t ) {
+	var v = tribonaccif( NaN );
+	t.strictEqual( isnanf( v ), true, 'returns expected value' );
+	t.end();
+});
+
+tape( 'if provided a non-integer, the function returns `NaN`', opts, function test( t ) {
+	var v = tribonaccif( 3.14 );
+	t.strictEqual( isnanf( v ), true, 'returns expected value' );
+	t.end();
+});
+
 tape( 'the function returns the nth Tribonacci number', opts, function test( t ) {
 	var v;
 	var i;