[ios, macos] Add cosine NSExpresssion operator.

2 files changed, 17 insertions, 0 deletions

diff --git a/platform/darwin/src/NSExpression+MGLAdditions.mm b/platform/darwin/src/NSExpression+MGLAdditions.mm
index d23da18597..aa01fd6126 100644
--- a/platform/darwin/src/NSExpression+MGLAdditions.mm
+++ b/platform/darwin/src/NSExpression+MGLAdditions.mm
@@ -69,6 +69,7 @@ const MGLExpressionInterpolationMode MGLExpressionInterpolationModeCubicBezier =
     INSTALL_METHOD(mgl_coalesce:);
     INSTALL_METHOD(mgl_does:have:);
     INSTALL_METHOD(mgl_acos:);
+    INSTALL_METHOD(mgl_cos:);
     INSTALL_METHOD(mgl_asin:);
     INSTALL_METHOD(mgl_atan:);
     
@@ -108,6 +109,13 @@ const MGLExpressionInterpolationMode MGLExpressionInterpolationModeCubicBezier =
 }
 
 /**
+ Computes the principal value of the cosine.
+ */
+- (NSNumber *)mgl_cos:(NSNumber *)number {
+    return @(cos(number.doubleValue));
+}
+
+/**
  Computes the principal value of the inverse sine.
  */
 - (NSNumber *)mgl_asin:(NSNumber *)number {
@@ -700,6 +708,7 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
             @"abs": @"abs:",
             @"round": @"mgl_round:",
             @"acos" : @"mgl_acos:",
+            @"cos" : @"mgl_cos:",
             @"asin" : @"mgl_asin:",
             @"atan" : @"mgl_atan:",
             @"floor": @"floor:",
@@ -945,6 +954,7 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
             @"length:": @"length",
             @"mgl_round:": @"round",
             @"mgl_acos:" : @"acos",
+            @"mgl_cos:" : @"cos",
             @"mgl_asin:" : @"asin",
             @"mgl_atan:" : @"atan",
             // Vararg aftermarket expressions need to be declared with an explicit and implicit first argument.
diff --git a/platform/darwin/test/MGLExpressionTests.mm b/platform/darwin/test/MGLExpressionTests.mm
index 20e252c06b..badc9904cc 100644
--- a/platform/darwin/test/MGLExpressionTests.mm
+++ b/platform/darwin/test/MGLExpressionTests.mm
@@ -539,6 +539,13 @@ using namespace std::string_literals;
         XCTAssertEqualObjects([NSExpression expressionWithMGLJSONObject:jsonExpression], expression);
     }
     {
+        NSExpression *expression = [NSExpression expressionForFunction:@"mgl_cos:" arguments:@[MGLConstantExpression(@0)]];
+        NSArray *jsonExpression = @[@"cos", @0];
+        XCTAssertEqualObjects(expression.mgl_jsonExpressionObject, jsonExpression);
+        XCTAssertEqualObjects([expression expressionValueWithObject:nil context:nil], @1);
+        XCTAssertEqualObjects([NSExpression expressionWithMGLJSONObject:jsonExpression], expression);
+    }
+    {
         NSExpression *expression = [NSExpression expressionForFunction:@"mgl_asin:" arguments:@[MGLConstantExpression(@0)]];
         NSArray *jsonExpression = @[@"asin", @0];
         XCTAssertEqualObjects(expression.mgl_jsonExpressionObject, jsonExpression);