3 files changed, 58 insertions, 25 deletions
diff --git a/platform/darwin/src/NSComparisonPredicate+MGLAdditions.mm b/platform/darwin/src/NSComparisonPredicate+MGLAdditions.mm
index 15aa71419d..af9216f9ce 100644
--- a/platform/darwin/src/NSComparisonPredicate+MGLAdditions.mm
+++ b/platform/darwin/src/NSComparisonPredicate+MGLAdditions.mm
@@ -140,10 +140,18 @@
             [NSException raise:NSInvalidArgumentException
                         format:@"NSPredicateOperatorType:%lu is not supported.", (unsigned long)self.predicateOperatorType];
     }
-    if (op) {
-        return @[op, self.leftExpression.mgl_jsonExpressionObject, self.rightExpression.mgl_jsonExpressionObject];
+    if (!op) {
+        return nil;
     }
-    return nil;
+    NSArray *comparisonArray = @[op, self.leftExpression.mgl_jsonExpressionObject, self.rightExpression.mgl_jsonExpressionObject];
+    if (self.options) {
+        NSDictionary *collatorObject = @{
+            @"case-sensitive": @(!(self.options & NSCaseInsensitivePredicateOption)),
+            @"diacritic-sensitive": @(!(self.options & NSDiacriticInsensitivePredicateOption)),
+        };
+        return [comparisonArray arrayByAddingObject:@[@"collator", collatorObject]];
+    }
+    return comparisonArray;
 }
 
 @end
diff --git a/platform/darwin/src/NSExpression+MGLAdditions.mm b/platform/darwin/src/NSExpression+MGLAdditions.mm
index 653e3d67e6..d03d7dbaec 100644
--- a/platform/darwin/src/NSExpression+MGLAdditions.mm
+++ b/platform/darwin/src/NSExpression+MGLAdditions.mm
@@ -784,6 +784,9 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
             
             return [NSExpression expressionForFunction:functionName
                                              arguments:subexpressions];
+        } else if ([op isEqualToString:@"collator"]) {
+            // Avoid wrapping collator options object in literal expression.
+            return [NSExpression expressionForFunction:@"MGL_FUNCTION" arguments:array];
         } else if ([op isEqualToString:@"literal"]) {
             if ([argumentObjects.firstObject isKindOfClass:[NSArray class]]) {
                 return [NSExpression expressionForAggregate:MGLSubexpressionsWithJSONObjects(argumentObjects.firstObject)];
@@ -1208,6 +1211,12 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
                 [NSException raise:NSInvalidArgumentException
                             format:@"Casting expression to %@ not yet implemented.", type];
             } else if ([function isEqualToString:@"MGL_FUNCTION"]) {
+                NSExpression *op = self.arguments.firstObject;
+                if (op.expressionType == NSConstantValueExpressionType
+                    && [op.constantValue isEqualToString:@"collator"]) {
+                    // Avoid wrapping collator options object in literal expression.
+                    return @[@"collator", self.arguments[1].constantValue];
+                }
                 return self.arguments.mgl_jsonExpressionObject;
             } else if (op == [MGLColor class] && [function isEqualToString:@"colorWithRed:green:blue:alpha:"]) {
                 NSArray *arguments = self.arguments.mgl_jsonExpressionObject;
diff --git a/platform/darwin/src/NSPredicate+MGLAdditions.mm b/platform/darwin/src/NSPredicate+MGLAdditions.mm
index 4b9a4177cb..d01b2c8f83 100644
--- a/platform/darwin/src/NSPredicate+MGLAdditions.mm
+++ b/platform/darwin/src/NSPredicate+MGLAdditions.mm
@@ -46,6 +46,15 @@ NSArray *MGLSubpredicatesWithJSONObjects(NSArray *objects) {
     return subpredicates;
 }
 
+static NSDictionary * const MGLPredicateOperatorTypesByJSONOperator = @{
+    @"==": @(NSEqualToPredicateOperatorType),
+    @"!=": @(NSNotEqualToPredicateOperatorType),
+    @"<": @(NSLessThanPredicateOperatorType),
+    @"<=": @(NSLessThanOrEqualToPredicateOperatorType),
+    @">": @(NSGreaterThanPredicateOperatorType),
+    @">=": @(NSGreaterThanOrEqualToPredicateOperatorType),
+};
+
 + (instancetype)predicateWithMGLJSONObject:(id)object {
     if ([object isEqual:@YES]) {
         return [NSPredicate predicateWithValue:YES];
@@ -58,30 +67,37 @@ NSArray *MGLSubpredicatesWithJSONObjects(NSArray *objects) {
     NSArray *objects = (NSArray *)object;
     NSString *op = objects.firstObject;
     
-    if ([op isEqualToString:@"=="]) {
-        NSArray *subexpressions = MGLSubexpressionsWithJSONObjects([objects subarrayWithRange:NSMakeRange(1, objects.count - 1)]);
-        return [NSPredicate predicateWithFormat:@"%@ == %@" argumentArray:subexpressions];
-    }
-    if ([op isEqualToString:@"!="]) {
-        NSArray *subexpressions = MGLSubexpressionsWithJSONObjects([objects subarrayWithRange:NSMakeRange(1, objects.count - 1)]);
-        return [NSPredicate predicateWithFormat:@"%@ != %@" argumentArray:subexpressions];
-    }
-    if ([op isEqualToString:@"<"]) {
-        NSArray *subexpressions = MGLSubexpressionsWithJSONObjects([objects subarrayWithRange:NSMakeRange(1, objects.count - 1)]);
-        return [NSPredicate predicateWithFormat:@"%@ < %@" argumentArray:subexpressions];
-    }
-    if ([op isEqualToString:@"<="]) {
-        NSArray *subexpressions = MGLSubexpressionsWithJSONObjects([objects subarrayWithRange:NSMakeRange(1, objects.count - 1)]);
-        return [NSPredicate predicateWithFormat:@"%@ <= %@" argumentArray:subexpressions];
-    }
-    if ([op isEqualToString:@">"]) {
-        NSArray *subexpressions = MGLSubexpressionsWithJSONObjects([objects subarrayWithRange:NSMakeRange(1, objects.count - 1)]);
-        return [NSPredicate predicateWithFormat:@"%@ > %@" argumentArray:subexpressions];
-    }
-    if ([op isEqualToString:@">="]) {
+    NSNumber *operatorTypeNumber = MGLPredicateOperatorTypesByJSONOperator[op];
+    if (operatorTypeNumber) {
+        NSPredicateOperatorType operatorType = (NSPredicateOperatorType)[operatorTypeNumber unsignedIntegerValue];
+        
+        NSComparisonPredicateOptions options = 0;
+        if (objects.count > 3) {
+            NSArray *collatorExpression = objects[3];
+            NSCAssert([collatorExpression isKindOfClass:[NSArray class]], @"Collators must be dictionaries.");
+            NSCAssert(collatorExpression.count == 2, @"Malformed collator expression");
+            NSDictionary *collator = collatorExpression[1];
+            NSCAssert([collator isKindOfClass:[NSDictionary class]], @"Malformed collator in collator expression");
+            
+            // Predicate options can’t express specific locales as collators can.
+            if (!collator[@"locale"]) {
+                if ([(collator[@"case-sensitive"] ?: @YES) isEqual:@NO]) {
+                    options |= NSCaseInsensitivePredicateOption;
+                }
+                if ([(collator[@"diacritic-sensitive"] ?: @YES) isEqual:@NO]) {
+                    options |= NSDiacriticInsensitivePredicateOption;
+                }
+            }
+        }
+        
         NSArray *subexpressions = MGLSubexpressionsWithJSONObjects([objects subarrayWithRange:NSMakeRange(1, objects.count - 1)]);
-        return [NSPredicate predicateWithFormat:@"%@ >= %@" argumentArray:subexpressions];
+        return [NSComparisonPredicate predicateWithLeftExpression:subexpressions[0]
+                                                  rightExpression:subexpressions[1]
+                                                         modifier:NSDirectPredicateModifier
+                                                             type:operatorType
+                                                          options:options];
     }
+    
     if ([op isEqualToString:@"!"]) {
         NSArray *subpredicates = MGLSubpredicatesWithJSONObjects([objects subarrayWithRange:NSMakeRange(1, objects.count - 1)]);
         if (subpredicates.count > 1) {