Fundamental Redesign of Evaluation

MathPad/MPNumber.m

@@ -8,44 +8,24 @@
 
 #import "MPNumber.h"
 
+#import "MPParsedExpression.h"
+
 #import "MPTokenStream.h"
 #import "MPToken.h"
 
 @implementation MPNumber
 
-- (instancetype)init
+- (instancetype)initWithNumber:(NSDecimalNumber *)number
 {
     self = [super init];
     if (self) {
+        NSAssert(number != nil, @"number must not be nil.");
+        _number = number;
     }
     return self;
 }
 
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    self = [self init];
-    if (self) {
-        [tokenStream beginIgnoringWhitespaceTokens];
-        MPToken *token = tokenStream.currentToken;
-        if (token.tokenType == MPNumberToken) {
-            _number = [NSDecimalNumber decimalNumberWithString:token.stringValue locale:[NSLocale currentLocale]];
-        } else {
-            @throw [NSException exceptionWithName:NSInternalInconsistencyException
-                                           reason:@"Expected Number"
-                                         userInfo:nil];
-        }
-        [tokenStream currentTokenConsumed];
-        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-    }
-    return self;
-}
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    return YES;
-}
-
-- (NSDecimalNumber *)evaluate
+- (NSDecimalNumber *)doEvaluation:(NSError *__autoreleasing *)error
 {
     return self.number;
 }