2 files changed, 16 insertions, 0 deletions
diff --git a/platform/darwin/src/NSExpression+MGLAdditions.h b/platform/darwin/src/NSExpression+MGLAdditions.h
index d13f0227b4..9ee7361448 100644
--- a/platform/darwin/src/NSExpression+MGLAdditions.h
+++ b/platform/darwin/src/NSExpression+MGLAdditions.h
@@ -63,6 +63,13 @@ FOUNDATION_EXTERN MGL_EXPORT const MGLExpressionInterpolationMode MGLExpressionI
 
 /**
  `NSExpression` variable that corresponds to the
+ <a href="https://www.mapbox.com/mapbox-gl-js/style-spec/#expressions-line-progress"><code>line-progress</code></a>
+ expression operator in the Mapbox Style Specification.
+ */
+@property (class, nonatomic, readonly) NSExpression *lineProgressVariableExpression;
+
+/**
+ `NSExpression` variable that corresponds to the
  <a href="https://www.mapbox.com/mapbox-gl-js/style-spec/#eexpressions-geometry-type"><code>geometry-type</code></a>
  expression operator in the Mapbox Style Specification.
  */
diff --git a/platform/darwin/src/NSExpression+MGLAdditions.mm b/platform/darwin/src/NSExpression+MGLAdditions.mm
index cb7f30f65a..9c12c6beac 100644
--- a/platform/darwin/src/NSExpression+MGLAdditions.mm
+++ b/platform/darwin/src/NSExpression+MGLAdditions.mm
@@ -542,6 +542,10 @@ const MGLExpressionInterpolationMode MGLExpressionInterpolationModeCubicBezier =
     return [NSExpression expressionForVariable:@"heatmapDensity"];
 }
 
++ (NSExpression *)lineProgressVariableExpression {
+    return [NSExpression expressionForVariable:@"lineProgress"];
+}
+
 + (NSExpression *)geometryTypeVariableExpression {
     return [NSExpression expressionForVariable:@"geometryType"];
 }
@@ -814,6 +818,8 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
             return NSExpression.zoomLevelVariableExpression;
         } else if ([op isEqualToString:@"heatmap-density"]) {
             return NSExpression.heatmapDensityVariableExpression;
+        } else if ([op isEqualToString:@"line-progress"]) {
+            return NSExpression.lineProgressVariableExpression;
         } else if ([op isEqualToString:@"geometry-type"]) {
             return NSExpression.geometryTypeVariableExpression;
         } else if ([op isEqualToString:@"id"]) {
@@ -911,6 +917,9 @@ NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) {
             if ([self.variable isEqualToString:@"heatmapDensity"]) {
                 return @[@"heatmap-density"];
             }
+            if ([self.variable isEqualToString:@"lineProgress"]) {
+                return @[@"line-progress"];
+            }
             if ([self.variable isEqualToString:@"zoomLevel"]) {
                 return @[@"zoom"];
             }