DDMathEvaluator.angleMeasurementMode. Fixes issue #29.

DDMathEvaluator has a new property to specify that the arguments to the trigonometric functions should be interpreted as being in degrees versus radians (the default).

Command line demo/main.m

@@ -83,6 +83,8 @@ int main (int argc, const char * argv[]) {
 
         } while (1);
 
+        DD_RELEASE(evaluator);
+
 		printf("Goodbye!\n");
 
 #if DD_HAS_ARC

DDMathParser/DDMathEvaluator+Private.h

@@ -13,6 +13,7 @@
 @interface DDMathEvaluator ()
 
 - (DDMathFunction) functionWithName:(NSString *)functionName;
+- (id) variableWithName:(NSString *)variableName;
 
 - (BOOL) functionExpressionFailedToResolve:(_DDFunctionExpression *)functionExpression error:(NSError **)error;
 

DDMathParser/DDMathEvaluator.h

@@ -13,15 +13,20 @@
 @class DDExpression;
 
 typedef DDMathFunction (^DDFunctionResolver)(NSString *);
+typedef NSNumber* (^DDVariableResolver)(NSString *);
 
 @interface DDMathEvaluator : NSObject {
     NSMutableArray *functions;
 	NSMutableDictionary * functionMap;
     NSMutableArray *rewriteRules;
     DDFunctionResolver functionResolver;
+    DDVariableResolver variableResolver;
+    DDAngleMeasurementMode angleMeasurementMode;
 }
 
+@property (nonatomic) DDAngleMeasurementMode angleMeasurementMode; // default is Radians
 @property (nonatomic, copy) DDFunctionResolver functionResolver;
+@property (nonatomic, copy) DDVariableResolver variableResolver;
 
 + (id) sharedMathEvaluator;
 

DDMathParser/DDMathEvaluator.m

@@ -30,7 +30,9 @@ - (_DDFunctionContainer *)functionContainerWithName:(NSString *)functionName;
 
 @implementation DDMathEvaluator
 
+@synthesize angleMeasurementMode=angleMeasurementMode;
 @synthesize functionResolver=functionResolver;
+@synthesize variableResolver=variableResolver;
 
 static DDMathEvaluator * _sharedEvaluator = nil;
 
@@ -47,6 +49,7 @@ - (id) init {
 	if (self) {
 		functions = [[NSMutableArray alloc] init];
         functionMap = [[NSMutableDictionary alloc] init];
+        angleMeasurementMode = DDAngleMeasurementModeRadians;
 
 		[self _registerStandardFunctions];
 	}
@@ -62,6 +65,7 @@ - (void) dealloc {
     [functionMap release];
     [rewriteRules release];
     [functionResolver release];
+    [variableResolver release];
 	[super dealloc];
 #endif
 }
@@ -126,6 +130,14 @@ - (BOOL) functionExpressionFailedToResolve:(_DDFunctionExpression *)functionExpr
 	return NO;
 }
 
+- (id) variableWithName:(NSString *)variableName {
+    id value = nil;
+    if (variableResolver != nil) {
+        value = variableResolver(variableName);
+    }
+    return value;
+}
+
 - (BOOL) addAlias:(NSString *)alias forFunctionName:(NSString *)functionName {
 	//we can't add an alias for a function that already exists
 	DDMathFunction function = [self functionWithName:alias];

DDMathParser/DDMathStringToken.m

@@ -78,7 +78,7 @@ - (NSString *)debugDescription {
         [d appendFormat:@"arity:%@, ", arityNames[arity]];
 
         NSInteger precedence = [self operatorPrecedence];
-        [d appendFormat:@"precedence:%d, ", precedence];
+        [d appendFormat:@"precedence:%ld, ", precedence];
 
         DDOperatorAssociativity assoc = [self operatorAssociativity];
         NSString *assocNames[2] = { @"LEFT", @"RIGHT" };

DDMathParser/DDTypes.h

@@ -49,4 +49,9 @@ typedef enum {
     DDErrorCodeInvalidNumberOfArguments,            //@"random() may only have up to 2 arguments"
     DDErrorCodeInvalidArgument,                     //@"upper bound (%ld) of random() must be larger than lower bound (%ld)"
 
-} DDErrorCode;
+} DDErrorCode;
+
+typedef enum {
+    DDAngleMeasurementModeRadians,
+    DDAngleMeasurementModeDegrees
+} DDAngleMeasurementMode;