refactor: modify C implementation to accept double

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
  - task: lint_filenames
    status: passed
  - task: lint_editorconfig
    status: passed
  - task: lint_markdown
    status: passed
  - task: lint_package_json
    status: na
  - task: lint_repl_help
    status: na
  - task: lint_javascript_src
    status: passed
  - task: lint_javascript_cli
    status: na
  - task: lint_javascript_examples
    status: na
  - task: lint_javascript_tests
    status: na
  - task: lint_javascript_benchmarks
    status: na
  - task: lint_python
    status: na
  - task: lint_r
    status: na
  - task: lint_c_src
    status: passed
  - task: lint_c_examples
    status: passed
  - task: lint_c_benchmarks
    status: passed
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
    status: na
  - task: lint_typescript_declarations
    status: na
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

Author: gunjjoshi

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

@@ -185,10 +185,10 @@ out = stdlib_base_fibonacci( 1 );
 
 The function accepts the following arguments:
 
--   **n**: `[in] int32_t` input value.
+-   **n**: `[in] double` input value.
 
 ```c
-double stdlib_base_fibonacci( const int32_t n );
+double stdlib_base_fibonacci( const double n );
 ```
 
 </section>
@@ -212,15 +212,14 @@ double stdlib_base_fibonacci( const int32_t n );
 ```c
 #include "stdlib/math/base/special/fibonacci.h"
 #include <stdio.h>
-#include <stdint.h>
 
 int main( void ) {
-    int32_t i;
+    double i;
     double v;
 
-    for ( i = 0; i < 79; i++ ) {
+    for ( i = 0.0; i < 79.0; i++ ) {
         v = stdlib_base_fibonacci( i );
-        printf( "fibonacci(%d) = %lf\n", i, v );
+        printf( "fibonacci(%lf) = %lf\n", i, v );
     }
 }
 ```

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

@@ -91,13 +91,13 @@ static double rand_double( void ) {
 */
 static double benchmark( void ) {
 	double elapsed;
-	int32_t x[ 100 ];
+	double x[ 100 ];
 	double t;
 	double y;
 	int i;
 
 	for ( i = 0; i < 100; i++ ) {
-		x[ i ] = (int32_t)floor( 40.0*rand_double() );
+		x[ i ] = floor( 40.0*rand_double() );
 	}
 
 	t = tic();

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

@@ -18,14 +18,13 @@
 
 #include "stdlib/math/base/special/fibonacci.h"
 #include <stdio.h>
-#include <stdint.h>
 
 int main( void ) {
-	int32_t i;
+	double i;
 	double v;
 
-	for ( i = 0; i < 79; i++ ) {
+	for ( i = 0.0; i < 79.0; i++ ) {
 		v = stdlib_base_fibonacci( i );
-		printf( "fibonacci(%d) = %lf\n", i, v );
+		printf( "fibonacci(%lf) = %lf\n", i, v );
 	}
 }

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

@@ -19,8 +19,6 @@
 #ifndef STDLIB_MATH_BASE_SPECIAL_FIBONACCI_H
 #define STDLIB_MATH_BASE_SPECIAL_FIBONACCI_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 Fibonacci number.
 */
-double stdlib_base_fibonacci( const int32_t n );
+double stdlib_base_fibonacci( const double n );
 
 #ifdef __cplusplus
 }

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

@@ -21,7 +21,7 @@
 // MODULES //
 
 var isnan = require( '@stdlib/math/base/assert/is-nan' );
-var isInteger = require( '@stdlib/math/base/assert/is-integer' );
+var isNonnegativeInteger = require( '@stdlib/math/base/assert/is-nonnegative-integer' );
 var MAX_FIBONACCI = require( '@stdlib/constants/float64/max-safe-nth-fibonacci' );
 var FIBONACCI = require( './fibonacci.json' );
 
@@ -77,8 +77,7 @@ var FIBONACCI = require( './fibonacci.json' );
 function fibonacci( n ) {
 	if (
 		isnan( n ) ||
-		isInteger( n ) === false ||
-		n < 0 ||
+		!isNonnegativeInteger( n ) ||
 		n > MAX_FIBONACCI
 	) {
 		return NaN;

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

@@ -37,7 +37,8 @@
       "libpath": [],
       "dependencies": [
         "@stdlib/math/base/napi/unary",
-        "@stdlib/constants/float64/max-safe-nth-fibonacci"
+        "@stdlib/constants/float64/max-safe-nth-fibonacci",
+        "@stdlib/math/base/assert/is-nonnegative-integer"
       ]
     },
     {
@@ -51,7 +52,8 @@
       "libraries": [],
       "libpath": [],
       "dependencies": [
-        "@stdlib/constants/float64/max-safe-nth-fibonacci"
+        "@stdlib/constants/float64/max-safe-nth-fibonacci",
+        "@stdlib/math/base/assert/is-nonnegative-integer"
       ]
     },
     {
@@ -65,7 +67,8 @@
       "libraries": [],
       "libpath": [],
       "dependencies": [
-        "@stdlib/constants/float64/max-safe-nth-fibonacci"
+        "@stdlib/constants/float64/max-safe-nth-fibonacci",
+        "@stdlib/math/base/assert/is-nonnegative-integer"
       ]
     }
   ]

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

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

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

@@ -18,6 +18,8 @@
 
 #include "stdlib/math/base/special/fibonacci.h"
 #include "stdlib/constants/float64/max_safe_nth_fibonacci.h"
+#include "stdlib/math/base/assert/is_nonnegative_integer.h"
+#include <stdint.h>
 
 static const int64_t fibonacci_value[ 79 ] = {
 	0,
@@ -108,12 +110,12 @@ static const int64_t fibonacci_value[ 79 ] = {
 * @return     output value
 *
 * @example
-* double out = stdlib_base_fibonacci( 1 );
-* // returns 1
+* double out = stdlib_base_fibonacci( 1.0 );
+* // returns 1.0
 */
-double stdlib_base_fibonacci( const int32_t n ) {
-	if ( n < 0 || n > STDLIB_CONSTANT_FLOAT64_MAX_SAFE_NTH_FIBONACCI ) {
+double stdlib_base_fibonacci( const double n ) {
+	if ( !stdlib_base_is_nonnegative_integer( n ) || n > STDLIB_CONSTANT_FLOAT64_MAX_SAFE_NTH_FIBONACCI ) {
 		return 0.0 / 0.0; // NaN
 	}
-	return fibonacci_value[ n ];
+	return fibonacci_value[ (int8_t)n ];
 }