Fundamental Redesign of Evaluation

MathPad/MPExpression.m

@@ -14,9 +14,9 @@
 #import "MPRangePath.h"
 
 #import "MPExpressionTokenizer.h"
-#import "MPTokenStream.h"
 #import "MPToken.h"
-#import "MPExpressionTree.h"
+#import "MPExpressionParser.h"
+#import "MPParsedExpression.h"
 
 #import "NSIndexPath+MPAdditions.h"
 
@@ -25,10 +25,6 @@
 NSString *const MPIllegalElementException = @"MPIllegalElementException";
 NSString *const MPIllegalElementExceptionElementKey = @"MPIllegalElementExceptionElementKey";
 
-NSString *const MPMathKitErrorDomain = @"MPMathKitErrorDomain";
-NSString *const MPExpressionPathErrorKey = @"MPExpressionPathErrorKey";
-
-
 
 @interface MPExpression () {
     NSMutableArray * _elements;
@@ -328,7 +324,11 @@ NSString *const MPExpressionPathErrorKey = @"MPExpressionPathErrorKey";
             break;
             
         case MPTokenReferenceFrame:
-            symbolIndex = [self.tokens[anIndex] range].location;
+            [self.tokens enumerateObjectsUsingBlock:^(id<MPToken> obj, NSUInteger idx, BOOL *stop) {
+                symbolIndex += obj.range.length;
+                *stop = idx >= anIndex - 1;
+            }];
+//            symbolIndex = [self.tokens[anIndex] range].location;
             break;
     }
     
@@ -556,17 +556,38 @@ NSString *const MPExpressionPathErrorKey = @"MPExpressionPathErrorKey";
 #pragma mark Evaluating Expressions
 
 
-- (NSDecimalNumber *)evaluateWithError:(NSError *__autoreleasing *)error
+- (NSDecimalNumber *)evaluateWithErrors:(NSArray *__autoreleasing *)errors
 {
-    MPExpressionTree *tree = [self parse];
-    return [tree validate:error] ? [tree evaluate] : nil;
+    NSArray *parsingErrors;
+    MPParsedExpression *parsedExpression = [self parse:&parsingErrors];
+    NSError *evaluationError;
+    NSDecimalNumber *result = parsedExpression ? [parsedExpression evaluate:&evaluationError] : nil;
+    if (errors) {
+        NSMutableArray *localErrors = [[NSMutableArray alloc] initWithCapacity:parsingErrors.count+1];
+        if (parsingErrors) {
+            [localErrors addObjectsFromArray:parsingErrors];
+        }
+        if (evaluationError) {
+            [localErrors addObject:evaluationError];
+        }
+        *errors = localErrors;
+    }
+    return result;
 }
 
 
-- (MPExpressionTree *)parse
+- (MPParsedExpression *)parse:(NSArray *__autoreleasing *)errors
 {
-    MPTokenStream *tokenStream = [[MPTokenStream alloc] initWithTokens:self.tokens];
-    return [[MPExpressionTree alloc] initWithTokenStream:tokenStream];
+    return [self parseExpectingVariable:NO
+                                 errors:errors];
+}
+
+
+- (MPParsedExpression *)parseExpectingVariable:(BOOL)flag
+                                        errors:(NSArray *__autoreleasing *)errors
+{
+    return [[[MPExpressionParser alloc] initWithExpression:self] parseExpectingVariableDefinition:flag
+                                                                                           errors:errors];
 }