1 files changed, 103 insertions, 290 deletions
diff --git a/platform/darwin/src/MGLStyleValue.mm b/platform/darwin/src/MGLStyleValue.mm
index 4dd6b550d8..74e1926f79 100644
--- a/platform/darwin/src/MGLStyleValue.mm
+++ b/platform/darwin/src/MGLStyleValue.mm
@@ -1,308 +1,121 @@
 #import "MGLStyleValue_Private.h"
 
+#include <mbgl/style/expression/expression.hpp>
+
 const MGLStyleFunctionOption MGLStyleFunctionOptionInterpolationBase = @"MGLStyleFunctionOptionInterpolationBase";
 const MGLStyleFunctionOption MGLStyleFunctionOptionDefaultValue = @"MGLStyleFunctionOptionDefaultValue";
 
-@implementation MGLStyleValue
-
-+ (instancetype)valueWithRawValue:(id)rawValue {
-    return [MGLConstantStyleValue valueWithRawValue:rawValue];
-}
-
-+ (instancetype)valueWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
-    return [MGLCameraStyleFunction functionWithInterpolationMode:MGLInterpolationModeExponential stops:stops options:@{MGLStyleFunctionOptionInterpolationBase: @(interpolationBase)}];
-}
-
-+ (instancetype)valueWithStops:(NSDictionary *)stops {
-    return [MGLCameraStyleFunction functionWithInterpolationMode:MGLInterpolationModeExponential stops:stops options:nil];
-}
-
-+ (instancetype)valueWithInterpolationMode:(MGLInterpolationMode)interpolationMode cameraStops:(NSDictionary *)cameraStops options:(NSDictionary *)options {
-    return [MGLCameraStyleFunction functionWithInterpolationMode:interpolationMode stops:cameraStops options:options];
-}
-
-+ (instancetype)valueWithInterpolationMode:(MGLInterpolationMode)interpolationMode sourceStops:(NSDictionary *)sourceStops attributeName:(NSString *)attributeName options:(NSDictionary *)options {
-    return [MGLSourceStyleFunction functionWithInterpolationMode:interpolationMode stops:sourceStops attributeName:attributeName options:options];
-}
-
-+ (instancetype)valueWithInterpolationMode:(MGLInterpolationMode)interpolationMode compositeStops:(NSDictionary *)compositeStops attributeName:(NSString *)attributeName options:(NSDictionary *)options {
-    return [MGLCompositeStyleFunction functionWithInterpolationMode:interpolationMode stops:compositeStops attributeName:attributeName options:options];
-}
-
-@end
-
-@implementation MGLConstantStyleValue
-
-+ (instancetype)valueWithRawValue:(id)rawValue {
-    return [[self alloc] initWithRawValue:rawValue];
+id MGLJSONObjectFromMBGLValue(const mbgl::style::expression::Value &value) {
+    return value.match([](const mbgl::NullValue) -> id {
+        return [NSNull null];
+    }, [](const bool value) {
+        return @(value);
+    }, [](const float value) {
+        return @(value);
+    }, [](const int64_t value) {
+        return @(value);
+    }, [](const double value) {
+        return @(value);
+    }, [](const std::string &value) {
+        return @(value.c_str());
+    }, [](const mbgl::Color &value) {
+        return [MGLColor mgl_colorWithColor:value];
+    }, [](const mbgl::style::Position &value) {
+        std::array<float, 3> spherical = value.getSpherical();
+        MGLSphericalPosition position = MGLSphericalPositionMake(spherical[0], spherical[1], spherical[2]);
+        return [NSValue valueWithMGLSphericalPosition:position];
+    }, [&](const std::vector<mbgl::style::expression::Value> &vector) {
+        NSMutableArray *array = [NSMutableArray arrayWithCapacity:vector.size()];
+        for (auto value : vector) {
+            [array addObject:MGLJSONObjectFromMBGLValue(value)];
+        }
+        return @[@"literal", array];
+    }, [&](const std::unordered_map<std::string, mbgl::style::expression::Value> &map) {
+        NSMutableDictionary *dictionary = [NSMutableDictionary dictionaryWithCapacity:map.size()];
+        for (auto &item : map) {
+            dictionary[@(item.first.c_str())] = MGLJSONObjectFromMBGLValue(item.second);
+        }
+        return @[@"literal", dictionary];
+    }, [](const auto &) -> id {
+        return nil;
+    });
 }
 
-- (instancetype)initWithRawValue:(id)rawValue {
-    if (self = [super init]) {
-        _rawValue = rawValue;
+id MGLJSONObjectFromMBGLExpression(const mbgl::style::expression::Expression &mbglExpression) {
+    using namespace mbgl::style::expression;
+    if (auto literalExpression = dynamic_cast<const Literal *>(&mbglExpression)) {
+        auto result = literalExpression->evaluate({ nullptr });
+        return result ? MGLJSONObjectFromMBGLValue(*result) : nil;
     }
-    return self;
-}
-
-- (NSString *)description {
-    return [self.rawValue description];
-}
-
-- (NSString *)debugDescription {
-    return [self.rawValue debugDescription];
-}
-
-- (BOOL)isEqual:(MGLConstantStyleValue *)other {
-    return [other isKindOfClass:[self class]] && [other.rawValue isEqual:self.rawValue];
-}
-
-- (NSUInteger)hash {
-    return [self.rawValue hash];
-}
-
-@end
-
-@implementation MGLStyleFunction
-
-+ (instancetype)functionWithStops:(NSDictionary *)stops {
-    return [MGLCameraStyleFunction functionWithInterpolationMode:MGLInterpolationModeExponential stops:stops options:nil];
-}
-
-+ (instancetype)functionWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
-    return [MGLCameraStyleFunction functionWithInterpolationMode:MGLInterpolationModeExponential stops:stops options:@{MGLStyleFunctionOptionInterpolationBase: @(interpolationBase)}];
-}
-
-- (instancetype)init {
-    if (self = [super init]) {
-        self.interpolationBase = 1.0;
-        self.stops = @{};
+    if (auto assertExpression = dynamic_cast<const ArrayAssertion *>(&mbglExpression)) {
+        NSMutableArray *inputs = [NSMutableArray array];
+        assertExpression->eachChild([&](const Expression &child) {
+            [inputs addObject:MGLJSONObjectFromMBGLExpression(child)];
+        });
+        return @[@"literal", inputs.lastObject];
     }
-    return self;
-}
-
-- (instancetype)initWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
-    if (self = [super init]) {
-        self.interpolationBase = interpolationBase;
-        self.stops = stops;
+    if (auto assertExpression = dynamic_cast<const Assertion *>(&mbglExpression)) {
+        NSMutableArray *inputs = [NSMutableArray array];
+        assertExpression->eachChild([&](const Expression &child) {
+            [inputs addObject:MGLJSONObjectFromMBGLExpression(child)];
+        });
+        return inputs.firstObject;
     }
-    return self;
-}
-
-- (NSString *)description {
-    return [NSString stringWithFormat:@"<%@: %p, \
-            stops = %@, \
-            interpolationBase = %f>",
-            NSStringFromClass([self class]), (void *)self,
-            self.stops,
-            self.interpolationBase];
-}
-
-- (BOOL)isEqual:(MGLStyleFunction *)other {
-    return ([other isKindOfClass:[self class]]
-            && [other.stops isEqualToDictionary:self.stops]
-            && other.interpolationBase == self.interpolationBase);
-}
-
-- (NSUInteger)hash {
-    return  self.stops.hash + @(self.interpolationBase).hash;
-}
-
-@end
-
-@implementation MGLCameraStyleFunction
-
-@dynamic stops;
-
-+ (instancetype)functionWithInterpolationMode:(MGLInterpolationMode)interpolationMode stops:(NSDictionary *)stops options:(NSDictionary *)options {
-    return [[self alloc] initWithInterpolationMode:interpolationMode stops:stops options:options];
-}
-
-- (instancetype)initWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
-    return [self initWithInterpolationMode:MGLInterpolationModeExponential stops:stops options:@{MGLStyleFunctionOptionInterpolationBase: @(interpolationBase)}];
-}
-
-- (instancetype)initWithInterpolationMode:(MGLInterpolationMode)interpolationMode stops:(NSDictionary *)stops options:(NSDictionary *)options {
-    if (![stops count]) {
-        [NSException raise:NSInvalidArgumentException
-                    format:@"Camera functions must have at least one stop."];
-        return {};
+    if (auto compoundExpression = dynamic_cast<const CompoundExpressionBase *>(&mbglExpression)) {
+        const std::string name = compoundExpression->getName();
+        mbgl::optional<std::size_t> parameterCount = compoundExpression->getParameterCount();
+        NSMutableArray *expressionObject = parameterCount ? [NSMutableArray arrayWithCapacity:*parameterCount + 1] : [NSMutableArray array];
+        [expressionObject addObject:@(name.c_str())];
+        compoundExpression->eachChild([&](const Expression &child) {
+            [expressionObject addObject:MGLJSONObjectFromMBGLExpression(child)];
+        });
+        return expressionObject;
     }
-
-    if (self = [super init]) {
-        self.interpolationMode = interpolationMode;
-        self.stops = stops;
-
-        if ([options.allKeys containsObject:MGLStyleFunctionOptionInterpolationBase]) {
-            if ([options[MGLStyleFunctionOptionInterpolationBase] isKindOfClass:[NSNumber class]]) {
-                NSNumber *value = (NSNumber *)options[MGLStyleFunctionOptionInterpolationBase];
-                self.interpolationBase = [value floatValue];
-            } else {
-                [NSException raise:NSInvalidArgumentException format:@"Interpolation base must be an NSNumber that represents a CGFloat."];
-            }
+    if (auto stepExpression = dynamic_cast<const Step *>(&mbglExpression)) {
+        auto &input = stepExpression->getInput();
+        NSMutableArray *expressionObject = [NSMutableArray arrayWithObjects:@"step", MGLJSONObjectFromMBGLExpression(*input.get()), nil];
+        stepExpression->eachStop([&](double stop, const Expression &child) {
+            [expressionObject addObject:@(stop)];
+            [expressionObject addObject:MGLJSONObjectFromMBGLExpression(child)];
+        });
+        if ([expressionObject[2] isEqual:@(-INFINITY)]) {
+            [expressionObject removeObjectAtIndex:2];
         }
+        return expressionObject;
     }
-    return self;
-}
-
-- (NSString *)description {
-    return [NSString stringWithFormat:@"<%@: %p, \
-            interpolationMode = %lu, \
-            stops = %@, \
-            interpolationBase = %f>",
-            NSStringFromClass([self class]), (void *)self,
-            (unsigned long)self.interpolationMode,
-            self.stops,
-            self.interpolationBase];
-}
-
-- (BOOL)isEqual:(MGLCameraStyleFunction *)other {
-    return ([other isKindOfClass:[self class]]
-            && other.interpolationMode == self.interpolationMode
-            && [other.stops isEqualToDictionary:self.stops]
-            && other.interpolationBase == self.interpolationBase);
-}
-
-- (NSUInteger)hash {
-    return  @(self.interpolationMode).hash + self.stops.hash + @(self.interpolationBase).hash;
-}
-
-@end
-
-@implementation MGLSourceStyleFunction
-
-@dynamic stops;
-
-+ (instancetype)functionWithInterpolationMode:(MGLInterpolationMode)interpolationMode stops:(NSDictionary *)stops attributeName:(NSString *)attributeName options:(NSDictionary *)options {
-    return [[self alloc] initWithInterpolationMode:interpolationMode stops:stops attributeName:attributeName options:options];
-}
-
-- (instancetype)initWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
-    return [self initWithInterpolationMode:MGLInterpolationModeExponential stops:stops attributeName:@"" options:@{MGLStyleFunctionOptionInterpolationBase: @(interpolationBase)}];
-}
-
-- (instancetype)initWithInterpolationMode:(MGLInterpolationMode)interpolationMode stops:(NSDictionary *)stops attributeName:(NSString *)attributeName options:(NSDictionary *)options {
-    if (self = [super init]) {
-        self.interpolationMode = interpolationMode;
-        self.stops = stops;
-        _attributeName = attributeName;
-
-        if ([options.allKeys containsObject:MGLStyleFunctionOptionDefaultValue]) {
-            if ([options[MGLStyleFunctionOptionDefaultValue] isKindOfClass:[MGLStyleValue class]]) {
-                MGLStyleValue *value = (MGLStyleValue *)options[MGLStyleFunctionOptionDefaultValue];
-                _defaultValue = value;
-            } else {
-                [NSException raise:NSInvalidArgumentException format:@"Default value must be an MGLStyleValue"];
-            }
-        }
-
-        if ([options.allKeys containsObject:MGLStyleFunctionOptionInterpolationBase]) {
-            if ([options[MGLStyleFunctionOptionInterpolationBase] isKindOfClass:[NSNumber class]]) {
-                NSNumber *value = (NSNumber *)options[MGLStyleFunctionOptionInterpolationBase];
-                self.interpolationBase = [value floatValue];
-            } else {
-                [NSException raise:NSInvalidArgumentException format:@"Interpolation base must be an NSNumber that represents a CGFloat."];
-            }
+    if (auto interpolateExpression = dynamic_cast<const InterpolateBase *>(&mbglExpression)) {
+        auto &interpolator = interpolateExpression->getInterpolator();
+        auto &input = interpolateExpression->getInput();
+        NSArray *interpolatorObject;
+        if (interpolator.is<ExponentialInterpolator>()) {
+            auto exponentialInterpolator = interpolator.get<ExponentialInterpolator>();
+            interpolatorObject = exponentialInterpolator.base == 1 ? @[@"linear"] : @[@"exponential", @(exponentialInterpolator.base)];
+        } else if (interpolator.is<CubicBezierInterpolator>()) {
+            auto cubicBezierInterpolator = interpolator.get<CubicBezierInterpolator>();
+            auto bezier = cubicBezierInterpolator.ub;
+            interpolatorObject = @[
+                @"cubic-bezier",
+                @(bezier.getP1().first), @(bezier.getP1().second),
+                @(bezier.getP2().first), @(bezier.getP2().second),
+            ];
+        } else {
+            NSCAssert(NO, @"Unrecognized interpolator type.");
         }
+        NSMutableArray *expressionObject = [NSMutableArray arrayWithObjects:@"interpolate", interpolatorObject, MGLJSONObjectFromMBGLExpression(*input.get()), nil];
+        interpolateExpression->eachStop([&](double stop, const Expression &child) {
+            [expressionObject addObject:@(stop)];
+            [expressionObject addObject:MGLJSONObjectFromMBGLExpression(child)];
+        });
+        return expressionObject;
     }
-    return self;
-}
-
-- (NSString *)description {
-    return [NSString stringWithFormat:@"<%@: %p, \
-            interpolationMode = %lu, \
-            stops = %@, \
-            attributeName = %@, \
-            defaultValue = %@, \
-            interpolationBase = %f>",
-            NSStringFromClass([self class]),
-            (void *)self,
-            (unsigned long)self.interpolationMode,
-            self.stops,
-            self.attributeName,
-            self.defaultValue,
-            self.interpolationBase];
-}
-
-- (BOOL)isEqual:(MGLSourceStyleFunction *)other {
-    return ([other isKindOfClass:[self class]]
-            && other.interpolationMode == self.interpolationMode
-            && ((self.stops && [other.stops isEqualToDictionary:self.stops]) || (!self.stops && !other.stops))
-            && [other.attributeName isEqual:self.attributeName]
-            && ((self.defaultValue && [other.defaultValue isEqual:self.defaultValue]) || (!self.defaultValue && !other.defaultValue))
-            && other.interpolationBase == self.interpolationBase);
-}
-
-- (NSUInteger)hash {
-    return @(self.interpolationMode).hash + self.stops.hash + self.attributeName.hash + self.defaultValue.hash + @(self.interpolationBase).hash;
-}
-
-@end
-
-@implementation MGLCompositeStyleFunction
-
-@dynamic stops;
-
-+ (instancetype)functionWithInterpolationMode:(MGLInterpolationMode)interpolationMode stops:(NSDictionary *)stops attributeName:(NSString *)attributeName options:(NSDictionary *)options {
-    return [[self alloc] initWithInterpolationMode:interpolationMode stops:stops attributeName:attributeName options:options];
-}
-
-- (instancetype)initWithInterpolationBase:(CGFloat)interpolationBase stops:(NSDictionary *)stops {
-    return [self initWithInterpolationMode:MGLInterpolationModeExponential stops:stops attributeName:@"" options:@{MGLStyleFunctionOptionInterpolationBase: @(interpolationBase)}];
-}
-
-- (instancetype)initWithInterpolationMode:(MGLInterpolationMode)interpolationMode stops:(NSDictionary *)stops attributeName:(NSString *)attributeName options:(NSDictionary *)options {
-    if (self = [super init]) {
-        self.interpolationMode = interpolationMode;
-        self.stops = stops;
-        _attributeName = attributeName;
-
-        if ([options.allKeys containsObject:MGLStyleFunctionOptionDefaultValue]) {
-            if ([options[MGLStyleFunctionOptionDefaultValue] isKindOfClass:[MGLStyleValue class]]) {
-                MGLStyleValue *value = (MGLStyleValue *)options[MGLStyleFunctionOptionDefaultValue];
-                _defaultValue = value;
-            } else {
-                [NSException raise:NSInvalidArgumentException format:@"Default value must be an MGLStyleValue"];
-            }
-        }
-
-        if ([options.allKeys containsObject:MGLStyleFunctionOptionInterpolationBase]) {
-            if ([options[MGLStyleFunctionOptionInterpolationBase] isKindOfClass:[NSNumber class]]) {
-                NSNumber *value = (NSNumber *)options[MGLStyleFunctionOptionInterpolationBase];
-                self.interpolationBase = [value floatValue];
-            } else {
-                [NSException raise:NSInvalidArgumentException format:@"Interpolation base must be an NSNumber that represents a CGFloat."];
-            }
-        }
+    if (auto caseExpression = dynamic_cast<const Case *>(&mbglExpression)) {
+        NSMutableArray *expressionObject = [NSMutableArray arrayWithObject:@"case"];
+        caseExpression->eachChild([&](const Expression &child) {
+            [expressionObject addObject:MGLJSONObjectFromMBGLExpression(child)];
+        });
+        return expressionObject;
     }
-    return self;
-}
-
-- (NSString *)description {
-    return [NSString stringWithFormat:@"<%@: %p, \
-            interpolationMode = %lu, \
-            stops = %@, \
-            attributeName = %@, \
-            defaultValue = %@, \
-            interpolationBase = %f>",
-            NSStringFromClass([self class]), (void *)self,
-            (unsigned long)self.interpolationMode,
-            self.stops,
-            self.attributeName,
-            self.defaultValue,
-            self.interpolationBase];
-}
-
-- (BOOL)isEqual:(MGLCompositeStyleFunction *)other {
-    return ([other isKindOfClass:[self class]]
-            && other.interpolationMode == self.interpolationMode
-            && [other.stops isEqualToDictionary:self.stops]
-            && [other.attributeName isEqual:self.attributeName]
-            && ((self.defaultValue && [other.defaultValue isEqual:self.defaultValue]) || (!self.defaultValue && !other.defaultValue))
-            && other.interpolationBase == self.interpolationBase);
-}
-
-- (NSUInteger)hash {
-    return  @(self.interpolationMode).hash + self.stops.hash + self.attributeName.hash + @(self.interpolationBase).hash;
+    NSCAssert(NO, @"Unrecognized expression type.");
+    return nil;
 }
 
-@end