diff options
Diffstat (limited to 'platform/darwin/src/NSExpression+MGLAdditions.mm')
| -rw-r--r-- | platform/darwin/src/NSExpression+MGLAdditions.mm | 585 |
1 files changed, 583 insertions, 2 deletions
diff --git a/platform/darwin/src/NSExpression+MGLAdditions.mm b/platform/darwin/src/NSExpression+MGLAdditions.mm index a7759cda9d..5ad565c398 100644 --- a/platform/darwin/src/NSExpression+MGLAdditions.mm +++ b/platform/darwin/src/NSExpression+MGLAdditions.mm @@ -1,13 +1,19 @@ -#import "NSExpression+MGLAdditions.h" +#import "NSExpression+MGLPrivateAdditions.h" #import "MGLTypes.h" #if TARGET_OS_IPHONE #import "UIColor+MGLAdditions.h" + #define MGLEdgeInsets UIEdgeInsets #else #import "NSColor+MGLAdditions.h" + #define MGLEdgeInsets NSEdgeInsets #endif +#import "NSPredicate+MGLAdditions.h" +#import "NSValue+MGLStyleAttributeAdditions.h" -@implementation NSExpression (MGLAdditions) +#import <mbgl/style/expression/expression.hpp> + +@implementation NSExpression (MGLPrivateAdditions) - (std::vector<mbgl::Value>)mgl_aggregateMBGLValue { if ([self.constantValue isKindOfClass:[NSArray class]] || [self.constantValue isKindOfClass:[NSSet class]]) { @@ -154,3 +160,578 @@ } @end + +@implementation NSObject (MGLExpressionAdditions) + +- (NSNumber *)mgl_number { + return nil; +} + +- (NSNumber *)mgl_numberWithFallbackValues:(id)fallbackValue, ... { + if (self.mgl_number) { + return self.mgl_number; + } + + va_list fallbackValues; + va_start(fallbackValues, fallbackValue); + for (id value = fallbackValue; value; value = va_arg(fallbackValues, id)) { + if ([value mgl_number]) { + return [value mgl_number]; + } + } + + return nil; +} + +@end + +@implementation NSNull (MGLExpressionAdditions) + +- (id)mgl_jsonExpressionObject { + return self; +} + +@end + +@implementation NSString (MGLExpressionAdditions) + +- (id)mgl_jsonExpressionObject { + return self; +} + +- (NSNumber *)mgl_number { + if (self.doubleValue || ![[NSDecimalNumber decimalNumberWithString:self] isEqual:[NSDecimalNumber notANumber]]) { + return @(self.doubleValue); + } + + return nil; +} + +@end + +@implementation NSNumber (MGLExpressionAdditions) + +- (id)mgl_interpolateWithCurveType:(NSString *)curveType + parameters:(NSArray *)parameters + stops:(NSDictionary<NSNumber *, id> *)stops { + [NSException raise:NSInvalidArgumentException + format:@"Interpolation expressions lack underlying Objective-C implementations."]; + return nil; +} + +- (id)mgl_stepWithMinimum:(id)minimum stops:(NSDictionary<NSNumber *, id> *)stops { + [NSException raise:NSInvalidArgumentException + format:@"Interpolation expressions lack underlying Objective-C implementations."]; + return nil; +} + +- (NSNumber *)mgl_number { + return self; +} + +- (id)mgl_jsonExpressionObject { + if ([self isEqualToNumber:@(M_E)]) { + return @[@"e"]; + } else if ([self isEqualToNumber:@(M_PI)]) { + return @[@"pi"]; + } + return self; +} + +@end + +@implementation MGLColor (MGLExpressionAdditions) + +- (id)mgl_jsonExpressionObject { + auto color = [self mgl_color]; + if (color.a == 1) { + return @[@"rgb", @(color.r * 255), @(color.g * 255), @(color.b * 255)]; + } + return @[@"rgba", @(color.r * 255), @(color.g * 255), @(color.b * 255), @(color.a)]; +} + +@end + +@implementation NSArray (MGLExpressionAdditions) + +- (id)mgl_jsonExpressionObject { + return [self valueForKeyPath:@"mgl_jsonExpressionObject"]; +} + +@end + +@implementation NSDictionary (MGLExpressionAdditions) + +- (id)mgl_jsonExpressionObject { + NSMutableDictionary *expressionObject = [NSMutableDictionary dictionaryWithCapacity:self.count]; + [self enumerateKeysAndObjectsUsingBlock:^(id _Nonnull key, id _Nonnull obj, BOOL * _Nonnull stop) { + expressionObject[[key mgl_jsonExpressionObject]] = [obj mgl_jsonExpressionObject]; + }]; + + return expressionObject; +} + +@end + +@implementation NSExpression (MGLExpressionAdditions) + +- (NSExpression *)mgl_expressionWithContext:(NSDictionary<NSString *, NSExpression *> *)context { + [NSException raise:NSInternalInconsistencyException + format:@"Assignment expressions lack underlying Objective-C implementations."]; + return self; +} + +@end + +@implementation NSExpression (MGLAdditions) + +static NSDictionary<NSString *, NSString *> *MGLFunctionNamesByExpressionOperator; +static NSDictionary<NSString *, NSString *> *MGLExpressionOperatorsByFunctionNames; + +NSArray *MGLSubexpressionsWithJSONObjects(NSArray *objects) { + NSMutableArray *subexpressions = [NSMutableArray arrayWithCapacity:objects.count]; + for (id object in objects) { + NSExpression *expression = [NSExpression mgl_expressionWithJSONObject:object]; + [subexpressions addObject:expression]; + } + return subexpressions; +} + ++ (instancetype)mgl_expressionWithJSONObject:(id)object { + static dispatch_once_t onceToken; + dispatch_once(&onceToken, ^{ + MGLFunctionNamesByExpressionOperator = @{ + @"+": @"add:to:", + @"-": @"from:subtract:", + @"*": @"multiply:by:", + @"/": @"divide:by:", + @"%": @"modulus:by:", + @"sqrt": @"sqrt:", + @"log10": @"log:", + @"ln": @"ln:", + @"^": @"raise:toPower:", + @"upcase": @"uppercase:", + @"downcase": @"lowercase:", + }; + }); + + if (!object || object == [NSNull null]) { + return [NSExpression expressionForConstantValue:nil]; + } + + if ([object isKindOfClass:[NSString class]] || + [object isKindOfClass:[NSNumber class]] || + [object isKindOfClass:[NSValue class]] || + [object isKindOfClass:[MGLColor class]]) { + return [NSExpression expressionForConstantValue:object]; + } + + if ([object isKindOfClass:[NSDictionary class]]) { + NSMutableDictionary *dictionary = [NSMutableDictionary dictionaryWithCapacity:[object count]]; + [object enumerateKeysAndObjectsUsingBlock:^(id _Nonnull key, id _Nonnull obj, BOOL * _Nonnull stop) { + dictionary[key] = [NSExpression mgl_expressionWithJSONObject:obj]; + }]; + return [NSExpression expressionForConstantValue:dictionary]; + } + + if ([object isKindOfClass:[NSArray class]]) { + NSArray *array = (NSArray *)object; + NSString *op = array.firstObject; + + NSArray *argumentObjects = [array subarrayWithRange:NSMakeRange(1, array.count - 1)]; + + NSString *functionName = MGLFunctionNamesByExpressionOperator[op]; + if (functionName) { + NSArray *subexpressions = MGLSubexpressionsWithJSONObjects(argumentObjects); + if ([op isEqualToString:@"+"] && argumentObjects.count > 2) { + NSExpression *subexpression = [NSExpression expressionForAggregate:subexpressions]; + return [NSExpression expressionForFunction:@"sum:" + arguments:@[subexpression]]; + } else if ([op isEqualToString:@"^"] && [argumentObjects.firstObject isEqual:@[@"e"]]) { + functionName = @"exp:"; + subexpressions = [subexpressions subarrayWithRange:NSMakeRange(1, subexpressions.count - 1)]; + } + + return [NSExpression expressionForFunction:functionName + arguments:subexpressions]; + } else if ([op isEqualToString:@"literal"]) { + if ([argumentObjects.firstObject isKindOfClass:[NSArray class]]) { + return [NSExpression expressionForAggregate:MGLSubexpressionsWithJSONObjects(argumentObjects.firstObject)]; + } + return [NSExpression mgl_expressionWithJSONObject:argumentObjects.firstObject]; + } else if ([op isEqualToString:@"to-boolean"]) { + NSExpression *operand = [NSExpression mgl_expressionWithJSONObject:argumentObjects.firstObject]; + return [NSExpression expressionForFunction:operand selectorName:@"boolValue" arguments:@[]]; + } else if ([op isEqualToString:@"to-number"]) { + NSExpression *operand = [NSExpression mgl_expressionWithJSONObject:argumentObjects.firstObject]; + argumentObjects = [argumentObjects subarrayWithRange:NSMakeRange(1, argumentObjects.count - 1)]; + NSArray *subexpressions = MGLSubexpressionsWithJSONObjects(argumentObjects); + return [NSExpression expressionForFunction:operand selectorName:@"mgl_numberWithFallbackValues:" arguments:subexpressions]; + } else if ([op isEqualToString:@"to-string"]) { + NSExpression *operand = [NSExpression mgl_expressionWithJSONObject:argumentObjects.firstObject]; + return [NSExpression expressionForFunction:operand selectorName:@"stringValue" arguments:@[]]; + } else if ([op isEqualToString:@"get"]) { + if (argumentObjects.count == 2) { + NSExpression *operand = [NSExpression mgl_expressionWithJSONObject:argumentObjects.lastObject]; + if ([argumentObjects.firstObject isKindOfClass:[NSString class]]) { + return [NSExpression expressionWithFormat:@"%@.%K", operand, argumentObjects.firstObject]; + } + NSExpression *key = [NSExpression mgl_expressionWithJSONObject:argumentObjects.firstObject]; + return [NSExpression expressionWithFormat:@"%@.%@", operand, key]; + } + return [NSExpression expressionForKeyPath:argumentObjects.firstObject]; + } else if ([op isEqualToString:@"length"]) { + NSArray *subexpressions = MGLSubexpressionsWithJSONObjects(argumentObjects); + return [NSExpression expressionForFunction:@"count:" arguments:@[subexpressions.firstObject]]; + } else if ([op isEqualToString:@"min"]) { + NSArray *subexpressions = MGLSubexpressionsWithJSONObjects(argumentObjects); + NSExpression *subexpression = [NSExpression expressionForAggregate:subexpressions]; + return [NSExpression expressionForFunction:@"min:" arguments:@[subexpression]]; + } else if ([op isEqualToString:@"max"]) { + NSArray *subexpressions = MGLSubexpressionsWithJSONObjects(argumentObjects); + NSExpression *subexpression = [NSExpression expressionForAggregate:subexpressions]; + return [NSExpression expressionForFunction:@"max:" arguments:@[subexpression]]; + } else if ([op isEqualToString:@"e"]) { + return [NSExpression expressionForConstantValue:@(M_E)]; + } else if ([op isEqualToString:@"pi"]) { + return [NSExpression expressionForConstantValue:@(M_PI)]; + } else if ([op isEqualToString:@"concat"]) { + NSArray *subexpressions = MGLSubexpressionsWithJSONObjects(argumentObjects); + NSExpression *operand = subexpressions.firstObject; + subexpressions = [subexpressions subarrayWithRange:NSMakeRange(1, subexpressions.count - 1)]; + return [NSExpression expressionForFunction:operand selectorName:@"stringByAppendingString:" arguments:subexpressions]; + } else if ([op isEqualToString:@"interpolate"]) { + NSArray *interpolationOptions = argumentObjects.firstObject; + NSString *curveType = interpolationOptions.firstObject; + NSExpression *curveTypeExpression = [NSExpression mgl_expressionWithJSONObject:curveType]; + id curveParameters; + if ([curveType isEqual:@"exponential"]) { + curveParameters = interpolationOptions[1]; + } else if ([curveType isEqualToString:@"cubic-bezier"]) { + curveParameters = @[@"literal", [interpolationOptions subarrayWithRange:NSMakeRange(1, 4)]]; + } + NSExpression *curveParameterExpression = [NSExpression mgl_expressionWithJSONObject:curveParameters]; + argumentObjects = [argumentObjects subarrayWithRange:NSMakeRange(1, argumentObjects.count - 1)]; + NSExpression *operand = [NSExpression mgl_expressionWithJSONObject:argumentObjects.firstObject]; + NSArray *stopExpressions = [argumentObjects subarrayWithRange:NSMakeRange(1, argumentObjects.count - 1)]; + NSMutableDictionary *stops = [NSMutableDictionary dictionaryWithCapacity:stopExpressions.count / 2]; + NSEnumerator *stopEnumerator = stopExpressions.objectEnumerator; + while (NSNumber *key = stopEnumerator.nextObject) { + NSExpression *valueExpression = stopEnumerator.nextObject; + stops[key] = [NSExpression mgl_expressionWithJSONObject:valueExpression]; + } + NSExpression *stopExpression = [NSExpression expressionForConstantValue:stops]; + return [NSExpression expressionForFunction:operand + selectorName:@"mgl_interpolateWithCurveType:parameters:stops:" + arguments:@[curveTypeExpression, curveParameterExpression, stopExpression]]; + } else if ([op isEqualToString:@"step"]) { + NSExpression *operand = [NSExpression mgl_expressionWithJSONObject:argumentObjects[0]]; + NSArray *stopExpressions = [argumentObjects subarrayWithRange:NSMakeRange(1, argumentObjects.count - 1)]; + NSExpression *minimum; + if (stopExpressions.count % 2) { + minimum = [NSExpression mgl_expressionWithJSONObject:stopExpressions.firstObject]; + stopExpressions = [stopExpressions subarrayWithRange:NSMakeRange(1, stopExpressions.count - 1)]; + } + NSMutableDictionary *stops = [NSMutableDictionary dictionaryWithCapacity:stopExpressions.count / 2]; + NSEnumerator *stopEnumerator = stopExpressions.objectEnumerator; + while (NSNumber *key = stopEnumerator.nextObject) { + NSExpression *valueExpression = stopEnumerator.nextObject; + if (minimum) { + stops[key] = [NSExpression mgl_expressionWithJSONObject:valueExpression]; + } else { + minimum = [NSExpression mgl_expressionWithJSONObject:valueExpression]; + } + } + NSExpression *stopExpression = [NSExpression expressionForConstantValue:stops]; + return [NSExpression expressionForFunction:operand + selectorName:@"mgl_stepWithMinimum:stops:" + arguments:@[minimum, stopExpression]]; + } else if ([op isEqualToString:@"zoom"]) { + return [NSExpression expressionForVariable:@"zoomLevel"]; + } else if ([op isEqualToString:@"heatmap-density"]) { + return [NSExpression expressionForVariable:@"heatmapDensity"]; + } else if ([op isEqualToString:@"let"]) { + NSExpression *operand = [NSExpression mgl_expressionWithJSONObject:argumentObjects.lastObject]; + NSArray *bindingObjects = [argumentObjects subarrayWithRange:NSMakeRange(0, argumentObjects.count - 1)]; + NSMutableDictionary *context = [NSMutableDictionary dictionaryWithCapacity:bindingObjects.count / 2]; + NSEnumerator *bindingEnumerator = bindingObjects.objectEnumerator; + while (NSString *key = bindingEnumerator.nextObject) { + context[key] = [NSExpression mgl_expressionWithJSONObject:bindingEnumerator.nextObject]; + } + return [NSExpression expressionForFunction:operand + selectorName:@"mgl_expressionWithContext:" + arguments:@[[NSExpression expressionForConstantValue:context]]]; + } else if ([op isEqualToString:@"var"]) { + return [NSExpression expressionForVariable:argumentObjects.firstObject]; + } else if ([op isEqualToString:@"case"]) { + NSPredicate *conditional = [NSPredicate mgl_predicateWithJSONObject:argumentObjects.firstObject]; + NSExpression *trueExpression = [NSExpression mgl_expressionWithJSONObject:argumentObjects[1]]; + NSExpression *falseExpression; + if (argumentObjects.count > 3) { + NSArray *falseObjects = [@[@"case"] arrayByAddingObjectsFromArray: + [argumentObjects subarrayWithRange:NSMakeRange(2, argumentObjects.count - 2)]]; + falseExpression = [NSExpression mgl_expressionWithJSONObject:falseObjects]; + } else { + falseExpression = [NSExpression mgl_expressionWithJSONObject:argumentObjects[2]]; + } + return [NSExpression expressionForConditional:conditional trueExpression:trueExpression falseExpression:falseExpression]; + } else { + [NSException raise:NSInvalidArgumentException + format:@"Expression operator %@ not yet implemented.", op]; + } + } + + [NSException raise:NSInvalidArgumentException + format:@"Unable to convert JSON object %@ to an NSExpression.", object]; + + return nil; +} + +- (id)mgl_jsonExpressionObject { + static dispatch_once_t onceToken; + dispatch_once(&onceToken, ^{ + MGLExpressionOperatorsByFunctionNames = @{ + @"add:to:": @"+", + @"from:subtract:": @"-", + @"multiply:by:": @"*", + @"divide:by:": @"/", + @"modulus:by:": @"%", + @"sqrt:": @"sqrt", + @"log:": @"log10", + @"ln:": @"ln", + @"raise:toPower:": @"^", + @"uppercase:": @"upcase", + @"lowercase:": @"downcase", + }; + }); + + switch (self.expressionType) { + case NSVariableExpressionType: { + if ([self.variable isEqualToString:@"heatmapDensity"]) { + return @[@"heatmap-density"]; + } + if ([self.variable isEqualToString:@"zoomLevel"]) { + return @[@"zoom"]; + } + return @[@"var", self.variable]; + } + + case NSConstantValueExpressionType: { + id constantValue = self.constantValue; + if (!constantValue || constantValue == [NSNull null]) { + return [NSNull null]; + } + if ([constantValue isEqual:@(M_E)]) { + return @[@"e"]; + } + if ([constantValue isEqual:@(M_PI)]) { + return @[@"pi"]; + } + if ([constantValue isKindOfClass:[NSArray class]] || + [constantValue isKindOfClass:[NSDictionary class]]) { + NSArray *collection = [constantValue mgl_jsonExpressionObject]; + return @[@"literal", collection]; + } + if ([constantValue isKindOfClass:[MGLColor class]]) { + auto color = [constantValue mgl_color]; + if (color.a == 1) { + return @[@"rgb", @(color.r * 255), @(color.g * 255), @(color.b * 255)]; + } + return @[@"rgba", @(color.r * 255), @(color.g * 255), @(color.b * 255), @(color.a)]; + } + if ([constantValue isKindOfClass:[NSValue class]]) { + const auto boxedValue = (NSValue *)constantValue; + if (strcmp([boxedValue objCType], @encode(CGVector)) == 0) { + // offset [x, y] + std::array<float, 2> mglValue = boxedValue.mgl_offsetArrayValue; + return @[@"literal", @[@(mglValue[0]), @(mglValue[1])]]; + } + if (strcmp([boxedValue objCType], @encode(MGLEdgeInsets)) == 0) { + // padding [x, y] + std::array<float, 4> mglValue = boxedValue.mgl_paddingArrayValue; + return @[@"literal", @[@(mglValue[0]), @(mglValue[1]), @(mglValue[2]), @(mglValue[3])]]; + } + } + return self.constantValue; + } + + case NSKeyPathExpressionType: { + NSArray *expressionObject; + for (NSString *pathComponent in self.keyPath.pathComponents.reverseObjectEnumerator) { + if (expressionObject) { + expressionObject = @[@"get", pathComponent, expressionObject]; + } else { + expressionObject = @[@"get", pathComponent]; + } + } + return expressionObject; + } + + case NSFunctionExpressionType: { + NSString *function = self.function; + NSString *op = MGLExpressionOperatorsByFunctionNames[function]; + if (op) { + NSArray *arguments = self.arguments.mgl_jsonExpressionObject; + return [@[op] arrayByAddingObjectsFromArray:arguments]; + } else if ([function isEqualToString:@"valueForKeyPath:"]) { + return @[@"get", self.arguments.firstObject.mgl_jsonExpressionObject, self.operand.mgl_jsonExpressionObject]; + } else if ([function isEqualToString:@"average:"]) { + NSExpression *sum = [NSExpression expressionForFunction:@"sum:" arguments:self.arguments]; + NSExpression *count = [NSExpression expressionForFunction:@"count:" arguments:self.arguments]; + return [NSExpression expressionForFunction:@"divide:by:" arguments:@[sum, count]].mgl_jsonExpressionObject; + } else if ([function isEqualToString:@"sum:"]) { + NSArray *arguments = [self.arguments.firstObject.collection valueForKeyPath:@"mgl_jsonExpressionObject"]; + return [@[@"+"] arrayByAddingObjectsFromArray:arguments]; + } else if ([function isEqualToString:@"count:"]) { + NSArray *arguments = self.arguments.firstObject.mgl_jsonExpressionObject; + return @[@"length", arguments]; + } else if ([function isEqualToString:@"min:"]) { + NSArray *arguments = [self.arguments.firstObject.collection valueForKeyPath:@"mgl_jsonExpressionObject"]; + return [@[@"min"] arrayByAddingObjectsFromArray:arguments]; + } else if ([function isEqualToString:@"max:"]) { + NSArray *arguments = [self.arguments.firstObject.collection valueForKeyPath:@"mgl_jsonExpressionObject"]; + return [@[@"max"] arrayByAddingObjectsFromArray:arguments]; + } else if ([function isEqualToString:@"exp:"]) { + return [NSExpression expressionForFunction:@"raise:toPower:" arguments:@[@(M_E), self.arguments.firstObject]].mgl_jsonExpressionObject; + } else if ([function isEqualToString:@"ceiling:"]) { + return [NSExpression expressionWithFormat:@"trunc:(%@) + TERNARY(modulus:by:(%@, 1) > 0, 1, 0)", + self.arguments.firstObject, self.arguments.firstObject].mgl_jsonExpressionObject; + } else if ([function isEqualToString:@"trunc:"]) { + return [NSExpression expressionWithFormat:@"%@ - modulus:by:(%@, 1)", + self.arguments.firstObject, self.arguments.firstObject].mgl_jsonExpressionObject; + } else if ([function isEqualToString:@"abs:"]) { + return [NSExpression expressionWithFormat:@"%@ * TERNARY(%@ > 0, 1, -1)", + self.arguments.firstObject, self.arguments.firstObject].mgl_jsonExpressionObject; + } else if ([function isEqualToString:@"floor:"]) { + return [NSExpression expressionWithFormat:@"trunc:(%@) - TERNARY(modulus:by:(%@, 1) < 0, 1, 0)", + self.arguments.firstObject, self.arguments.firstObject].mgl_jsonExpressionObject; + } else if ([function isEqualToString:@"stringByAppendingString:"]) { + NSArray *arguments = self.arguments.mgl_jsonExpressionObject; + return [@[@"concat", self.operand.mgl_jsonExpressionObject] arrayByAddingObjectsFromArray:arguments]; + } else if ([function isEqualToString:@"boolValue"]) { + return @[@"to-boolean", self.operand.mgl_jsonExpressionObject]; + } else if ([function isEqualToString:@"mgl_numberWithFallbackValues:"] || + [function isEqualToString:@"decimalValue"] || + [function isEqualToString:@"floatValue"] || + [function isEqualToString:@"doubleValue"]) { + NSArray *arguments = self.arguments.mgl_jsonExpressionObject; + return [@[@"to-number", self.operand.mgl_jsonExpressionObject] arrayByAddingObjectsFromArray:arguments]; + } else if ([function isEqualToString:@"stringValue"]) { + return @[@"to-string", self.operand.mgl_jsonExpressionObject]; + } else if ([function isEqualToString:@"noindex:"]) { + return self.arguments.firstObject.mgl_jsonExpressionObject; + } else if ([function isEqualToString:@"mgl_interpolateWithCurveType:parameters:stops:"]) { + if (self.arguments.count < 3) { + [NSException raise:NSInvalidArgumentException format: + @"Too few arguments to ‘mgl_interpolateWithCurveType:parameters:stops:’ function; expected 3 arguments."]; + } else if (self.arguments.count > 3) { + [NSException raise:NSInvalidArgumentException format: + @"%lu unexpected arguments to ‘mgl_interpolateWithCurveType:parameters:stops:’ function; expected 3 arguments.", + self.arguments.count - 3]; + } + NSString *curveType = self.arguments.firstObject.constantValue; + NSMutableArray *interpolationArray = [NSMutableArray arrayWithObject:curveType]; + if ([curveType isEqualToString:@"exponential"]) { + id base = [self.arguments[1] mgl_jsonExpressionObject]; + [interpolationArray addObject:base]; + } else if ([curveType isEqualToString:@"cubic-bezier"]) { + NSArray *controlPoints = [self.arguments[1].collection mgl_jsonExpressionObject]; + [interpolationArray addObjectsFromArray:controlPoints]; + } + NSMutableArray *expressionObject = [NSMutableArray arrayWithObjects:@"interpolate", interpolationArray, self.operand.mgl_jsonExpressionObject, nil]; + NSDictionary<NSNumber *, NSExpression *> *stops = self.arguments[2].constantValue; + for (NSNumber *key in [stops.allKeys sortedArrayUsingSelector:@selector(compare:)]) { + [expressionObject addObject:key]; + [expressionObject addObject:[stops[key] mgl_jsonExpressionObject]]; + } + return expressionObject; + } else if ([function isEqualToString:@"mgl_stepWithMinimum:stops:"]) { + id minimum = self.arguments.firstObject.mgl_jsonExpressionObject; + NSMutableArray *expressionObject = [NSMutableArray arrayWithObjects:@"step", self.operand.mgl_jsonExpressionObject, minimum, nil]; + NSDictionary<NSNumber *, NSExpression *> *stops = self.arguments[1].constantValue; + for (NSNumber *key in [stops.allKeys sortedArrayUsingSelector:@selector(compare:)]) { + [expressionObject addObject:key]; + [expressionObject addObject:[stops[key] mgl_jsonExpressionObject]]; + } + return expressionObject; + } else if ([function isEqualToString:@"mgl_expressionWithContext:"]) { + id context = self.arguments.firstObject; + if ([context isKindOfClass:[NSExpression class]]) { + context = [context constantValue]; + } + NSMutableArray *expressionObject = [NSMutableArray arrayWithObjects:@"let", nil]; + [context enumerateKeysAndObjectsUsingBlock:^(id _Nonnull key, NSExpression * _Nonnull obj, BOOL * _Nonnull stop) { + [expressionObject addObject:key]; + [expressionObject addObject:obj.mgl_jsonExpressionObject]; + }]; + [expressionObject addObject:self.operand.mgl_jsonExpressionObject]; + return expressionObject; + } else if ([function isEqualToString:@"median:"] || + [function isEqualToString:@"mode:"] || + [function isEqualToString:@"stddev:"] || + [function isEqualToString:@"random"] || + [function isEqualToString:@"randomn:"] || + [function isEqualToString:@"now"] || + [function isEqualToString:@"bitwiseAnd:with:"] || + [function isEqualToString:@"bitwiseOr:with:"] || + [function isEqualToString:@"bitwiseXor:with:"] || + [function isEqualToString:@"leftshift:by:"] || + [function isEqualToString:@"rightshift:by:"] || + [function isEqualToString:@"onesComplement:"] || + [function isEqualToString:@"distanceToLocation:fromLocation:"]) { + [NSException raise:NSInvalidArgumentException + format:@"Expression function %@ not yet implemented.", function]; + return nil; + } else { + [NSException raise:NSInvalidArgumentException + format:@"Unrecognized expression function %@.", function]; + return nil; + } + } + + case NSConditionalExpressionType: { + NSMutableArray *arguments = [NSMutableArray arrayWithObjects:self.predicate.mgl_jsonExpressionObject, self.trueExpression.mgl_jsonExpressionObject, nil]; + if (self.falseExpression.expressionType == NSConditionalExpressionType) { + // Fold nested conditionals into a single case expression. + NSArray *falseArguments = self.falseExpression.mgl_jsonExpressionObject; + falseArguments = [falseArguments subarrayWithRange:NSMakeRange(1, falseArguments.count - 1)]; + [arguments addObjectsFromArray:falseArguments]; + } else { + [arguments addObject:self.falseExpression.mgl_jsonExpressionObject]; + } + + [arguments insertObject:@"case" atIndex:0]; + return arguments; + } + + case NSAggregateExpressionType: { + NSArray *collection = [self.collection valueForKeyPath:@"mgl_jsonExpressionObject"]; + return @[@"literal", collection]; + } + + case NSEvaluatedObjectExpressionType: + case NSUnionSetExpressionType: + case NSIntersectSetExpressionType: + case NSMinusSetExpressionType: + case NSSubqueryExpressionType: + case NSAnyKeyExpressionType: + case NSBlockExpressionType: + [NSException raise:NSInvalidArgumentException + format:@"Expression type %lu not yet implemented.", self.expressionType]; + } + + // NSKeyPathSpecifierExpression + if (self.expressionType == 10) { + return self.description; + } + // An assignment expression type is present in the BNF grammar, but the + // corresponding NSExpressionType value and property getters are missing. + if (self.expressionType == 12) { + [NSException raise:NSInvalidArgumentException + format:@"Assignment expressions not yet implemented."]; + } + + return nil; +} + +@end |