Project Update (stable)

MathKit/MathKit.h

@@ -10,31 +10,16 @@
 #import "MPExpressionElement.h"
 #import "NSString+MPExpressionElement.h"
 #import "MPFunction.h"
-#import "MPSuffixFunction.h"
 
 #import "MPSumFunction.h"
 #import "MPParenthesisFunction.h"
 #import "MPPowerFunction.h"
 #import "MPFractionFunction.h"
-#import "MPRootFunction.h"
 
 #import "MPToken.h"
 #import "MPFunction+MPToken.h"
 #import "MPTokenStream.h"
 
-#import "MPExpressionTreeElement.h"
-#import "MPExpressionTree.h"
-#import "MPSummand.h"
-#import "MPOperatorChain.h"
-#import "MPProduct.h"
-#import "MPFactor.h"
-#import "MPValueGroup.h"
-#import "MPNumber.h"
-#import "MPVariable.h"
-#import "MPFunction+MPValue.h"
-#import "MPFunctionValue.h"
-#import "MPUnexpectedSymbolValue.h"
-#import "MPFactorial.h"
 
 #import "MPEvaluationContext.h"
 #import "MPMathRules.h"

MathPad.xcodeproj/project.pbxproj

@@ -7,10 +7,6 @@
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-		3B3A4AAF19F71855001E9D54 /* MPRootFunction.m in Sources */ = {isa = PBXBuildFile; fileRef = 3B3A4AAD19F71855001E9D54 /* MPRootFunction.m */; };
-		3B3A4AB219F71A11001E9D54 /* MPRootFunctionLayout.h in Headers */ = {isa = PBXBuildFile; fileRef = 3B3A4AB019F71A11001E9D54 /* MPRootFunctionLayout.h */; };
-		3B3A4AB319F71A11001E9D54 /* MPRootFunctionLayout.m in Sources */ = {isa = PBXBuildFile; fileRef = 3B3A4AB119F71A11001E9D54 /* MPRootFunctionLayout.m */; };
 		3B52CEC119BB9FA900CEDCFC /* MathKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 3B85830D19BB5E5500D76A8D /* MathKit.framework */; };
 		3B52CEDC19BEE63000CEDCFC /* NSRegularExpression+MPParsingAdditions.h in Headers */ = {isa = PBXBuildFile; fileRef = 3B52CEDA19BEE63000CEDCFC /* NSRegularExpression+MPParsingAdditions.h */; };
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@@ -24,33 +20,12 @@
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-		3B69B68519E6E8B20028E608 /* MPExpressionTree.h in Headers */ = {isa = PBXBuildFile; fileRef = 3B69B68319E6E8B20028E608 /* MPExpressionTree.h */; };
-		3B69B68619E6E8B20028E608 /* MPExpressionTree.m in Sources */ = {isa = PBXBuildFile; fileRef = 3B69B68419E6E8B20028E608 /* MPExpressionTree.m */; };
-		3B69B68919E6E9280028E608 /* MPSummand.h in Headers */ = {isa = PBXBuildFile; fileRef = 3B69B68719E6E9280028E608 /* MPSummand.h */; };
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-		3B69B68E19E6EB0D0028E608 /* MPProduct.m in Sources */ = {isa = PBXBuildFile; fileRef = 3B69B68C19E6EB0D0028E608 /* MPProduct.m */; };
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-		3B69B6A919E6F2AF0028E608 /* MPFunction+MPValue.h in Headers */ = {isa = PBXBuildFile; fileRef = 3B69B6A719E6F2AF0028E608 /* MPFunction+MPValue.h */; };
+		3B69B6BD19E948740028E608 /* MPElementaryFunctionTerm.h in Headers */ = {isa = PBXBuildFile; fileRef = 3B69B6BB19E948740028E608 /* MPElementaryFunctionTerm.h */; };
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-		3B69B6BE19E948740028E608 /* MPFunctionValue.m in Sources */ = {isa = PBXBuildFile; fileRef = 3B69B6BC19E948740028E608 /* MPFunctionValue.m */; };
-		3B69B6C119E953590028E608 /* MPFactorial.h in Headers */ = {isa = PBXBuildFile; fileRef = 3B69B6BF19E953590028E608 /* MPFactorial.h */; };
-		3B69B6C219E953590028E608 /* MPFactorial.m in Sources */ = {isa = PBXBuildFile; fileRef = 3B69B6C019E953590028E608 /* MPFactorial.m */; };
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@@ -86,6 +61,8 @@
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 		3B85834C19BB661100D76A8D /* MathKit.h in Headers */ = {isa = PBXBuildFile; fileRef = 3B85833219BB5F2D00D76A8D /* MathKit.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		3B9265C71A2147DF00AD2809 /* MPNegatedTerm.h in Headers */ = {isa = PBXBuildFile; fileRef = 3B9265C51A2147DF00AD2809 /* MPNegatedTerm.h */; };
+		3B9265C81A2147DF00AD2809 /* MPNegatedTerm.m in Sources */ = {isa = PBXBuildFile; fileRef = 3B9265C61A2147DF00AD2809 /* MPNegatedTerm.m */; };
 		3BB18AA519CDB3A900986DA0 /* MPTokenStream.h in Headers */ = {isa = PBXBuildFile; fileRef = 3BB18AA319CDB3A900986DA0 /* MPTokenStream.h */; };
 		3BB18AA619CDB3A900986DA0 /* MPTokenStream.m in Sources */ = {isa = PBXBuildFile; fileRef = 3BB18AA419CDB3A900986DA0 /* MPTokenStream.m */; };
 		3BBEA92C19BB680B00133766 /* MathKit.framework in CopyFiles */ = {isa = PBXBuildFile; fileRef = 3B85830D19BB5E5500D76A8D /* MathKit.framework */; };
@@ -105,6 +82,28 @@
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 		3BC4661419B245C60033F13A /* Fonts in Resources */ = {isa = PBXBuildFile; fileRef = 3BC4661319B245C60033F13A /* Fonts */; };
+		3BCA0C801A12619500C9E3E0 /* MPTerm.h in Headers */ = {isa = PBXBuildFile; fileRef = 3BCA0C7E1A12619500C9E3E0 /* MPTerm.h */; };
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+		3BEFF7731A180C8800301C0C /* MPFractionTerm.m in Sources */ = {isa = PBXBuildFile; fileRef = 3BEFF7711A180C8800301C0C /* MPFractionTerm.m */; };
+		3BF54BB91A18D08400883BFA /* MPExpressionParser.h in Headers */ = {isa = PBXBuildFile; fileRef = 3BF54BB71A18D08400883BFA /* MPExpressionParser.h */; };
+		3BF54BBA1A18D08400883BFA /* MPExpressionParser.m in Sources */ = {isa = PBXBuildFile; fileRef = 3BF54BB81A18D08400883BFA /* MPExpressionParser.m */; };
 		3BF59AFE19D80ECC00E54292 /* MPFunctionsViewController.h in Headers */ = {isa = PBXBuildFile; fileRef = 3BF59AFB19D80ECC00E54292 /* MPFunctionsViewController.h */; };
 		3BF59AFF19D80ECC00E54292 /* MPFunctionsViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = 3BF59AFC19D80ECC00E54292 /* MPFunctionsViewController.m */; };
 		3BF59B0019D80ECC00E54292 /* MPFunctionsViewController.xib in Resources */ = {isa = PBXBuildFile; fileRef = 3BF59AFD19D80ECC00E54292 /* MPFunctionsViewController.xib */; };
@@ -161,10 +160,6 @@
 
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@@ -183,33 +178,12 @@
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-		3B69B6C419E95B250028E608 /* MPOperatorChain.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPOperatorChain.m; sourceTree = "<group>"; };
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@@ -239,6 +213,8 @@
 		3B87E35C1900933200259938 /* MPRangePath.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPRangePath.m; sourceTree = "<group>"; };
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 		3B87E35F19009D5F00259938 /* MPFunction.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPFunction.m; sourceTree = "<group>"; };
+		3B9265C51A2147DF00AD2809 /* MPNegatedTerm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPNegatedTerm.h; sourceTree = "<group>"; };
+		3B9265C61A2147DF00AD2809 /* MPNegatedTerm.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPNegatedTerm.m; sourceTree = "<group>"; };
 		3BB09EB01905DE500080A5ED /* MPExpressionStorage.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = MPExpressionStorage.h; path = ../MathPad/MPExpressionStorage.h; sourceTree = "<group>"; };
 		3BB09EB11905DE500080A5ED /* MPExpressionStorage.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = MPExpressionStorage.m; path = ../MathPad/MPExpressionStorage.m; sourceTree = "<group>"; };
 		3BB09EC71906FD830080A5ED /* MPSumFunction.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPSumFunction.h; sourceTree = "<group>"; };
@@ -253,6 +229,28 @@
 		3BC4661319B245C60033F13A /* Fonts */ = {isa = PBXFileReference; lastKnownFileType = folder; path = Fonts; sourceTree = "<group>"; };
 		3BC4661519B365070033F13A /* MPArrayCache.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPArrayCache.h; sourceTree = "<group>"; };
 		3BC4661619B365070033F13A /* MPArrayCache.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPArrayCache.m; sourceTree = "<group>"; };
+		3BCA0C7E1A12619500C9E3E0 /* MPTerm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPTerm.h; sourceTree = "<group>"; };
+		3BCA0C7F1A12619500C9E3E0 /* MPTerm.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPTerm.m; sourceTree = "<group>"; };
+		3BCA0C831A1405C000C9E3E0 /* MPFunctionTerm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPFunctionTerm.h; sourceTree = "<group>"; };
+		3BCA0C841A1405C000C9E3E0 /* MPFunctionTerm.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPFunctionTerm.m; sourceTree = "<group>"; };
+		3BEFF74B1A16A4DA00301C0C /* MPSumTerm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPSumTerm.h; sourceTree = "<group>"; };
+		3BEFF74C1A16A4DA00301C0C /* MPSumTerm.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPSumTerm.m; sourceTree = "<group>"; };
+		3BEFF74F1A16B06600301C0C /* MPParsedExpression.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPParsedExpression.h; sourceTree = "<group>"; };
+		3BEFF7501A16B06600301C0C /* MPParsedExpression.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPParsedExpression.m; sourceTree = "<group>"; };
+		3BEFF7531A17AA3200301C0C /* MPProductTerm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPProductTerm.h; sourceTree = "<group>"; };
+		3BEFF7541A17AA3200301C0C /* MPProductTerm.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPProductTerm.m; sourceTree = "<group>"; };
+		3BEFF7601A1804AF00301C0C /* MPFactorialTerm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPFactorialTerm.h; sourceTree = "<group>"; };
+		3BEFF7611A1804AF00301C0C /* MPFactorialTerm.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPFactorialTerm.m; sourceTree = "<group>"; };
+		3BEFF7641A18066300301C0C /* MPSumFunctionTerm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPSumFunctionTerm.h; sourceTree = "<group>"; };
+		3BEFF7651A18066300301C0C /* MPSumFunctionTerm.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPSumFunctionTerm.m; sourceTree = "<group>"; };
+		3BEFF7681A1807B000301C0C /* MPParenthesisTerm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPParenthesisTerm.h; sourceTree = "<group>"; };
+		3BEFF7691A1807B000301C0C /* MPParenthesisTerm.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPParenthesisTerm.m; sourceTree = "<group>"; };
+		3BEFF76C1A18083C00301C0C /* MPPowerTerm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPPowerTerm.h; sourceTree = "<group>"; };
+		3BEFF76D1A18083C00301C0C /* MPPowerTerm.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPPowerTerm.m; sourceTree = "<group>"; };
+		3BEFF7701A180C8800301C0C /* MPFractionTerm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPFractionTerm.h; sourceTree = "<group>"; };
+		3BEFF7711A180C8800301C0C /* MPFractionTerm.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPFractionTerm.m; sourceTree = "<group>"; };
+		3BF54BB71A18D08400883BFA /* MPExpressionParser.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPExpressionParser.h; sourceTree = "<group>"; };
+		3BF54BB81A18D08400883BFA /* MPExpressionParser.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPExpressionParser.m; sourceTree = "<group>"; };
 		3BF59AFB19D80ECC00E54292 /* MPFunctionsViewController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPFunctionsViewController.h; sourceTree = "<group>"; };
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@@ -325,38 +323,6 @@
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
-		3B69B68219E6E8A50028E608 /* Expression Tree */ = {
-			isa = PBXGroup;
-			children = (
-				3B69B68F19E6ED6E0028E608 /* MPExpressionTreeElement.h */,
-				3B69B68319E6E8B20028E608 /* MPExpressionTree.h */,
-				3B69B68419E6E8B20028E608 /* MPExpressionTree.m */,
-				3B69B68719E6E9280028E608 /* MPSummand.h */,
-				3B69B68819E6E9280028E608 /* MPSummand.m */,
-				3B69B6C319E95B250028E608 /* MPOperatorChain.h */,
-				3B69B6C419E95B250028E608 /* MPOperatorChain.m */,
-				3B69B68B19E6EB0D0028E608 /* MPProduct.h */,
-				3B69B68C19E6EB0D0028E608 /* MPProduct.m */,
-				3B69B6AF19E8175F0028E608 /* MPFactor.h */,
-				3B69B6B019E8175F0028E608 /* MPFactor.m */,
-				3B69B69519E6F0780028E608 /* MPValueGroup.h */,
-				3B69B69619E6F0780028E608 /* MPValueGroup.m */,
-				3B69B69B19E6F2110028E608 /* MPNumber.h */,
-				3B69B69C19E6F2110028E608 /* MPNumber.m */,
-				3B69B69F19E6F2420028E608 /* MPVariable.h */,
-				3B69B6A019E6F2420028E608 /* MPVariable.m */,
-				3B69B6A719E6F2AF0028E608 /* MPFunction+MPValue.h */,
-				3B69B6A819E6F2AF0028E608 /* MPFunction+MPValue.m */,
-				3B69B6BB19E948740028E608 /* MPFunctionValue.h */,
-				3B69B6BC19E948740028E608 /* MPFunctionValue.m */,
-				3B69B6B319E88E750028E608 /* MPUnexpectedSymbolValue.h */,
-				3B69B6B419E88E750028E608 /* MPUnexpectedSymbolValue.m */,
-				3B69B6BF19E953590028E608 /* MPFactorial.h */,
-				3B69B6C019E953590028E608 /* MPFactorial.m */,
-			);
-			name = "Expression Tree";
-			sourceTree = "<group>";
-		};
 		3B7172E519C7112C00FEAA5B /* Resources */ = {
 			isa = PBXGroup;
 			children = (
@@ -423,8 +389,6 @@
 			isa = PBXGroup;
 			children = (
 				3BC46B4B19B38CB60033F13A /* Base Expression Classes */,
-				3B69B68219E6E8A50028E608 /* Expression Tree */,
-				3BB09EBC1905EF210080A5ED /* Functions */,
 				3B87E35B1900933200259938 /* MPRangePath.h */,
 				3B87E35C1900933200259938 /* MPRangePath.m */,
 				3BC46B4D19B38CFB0033F13A /* Helpers */,
@@ -455,8 +419,6 @@
 				3B5FF73A19DB2FF500C8348A /* MPPowerFunction.m */,
 				3B69B67A19E4915E0028E608 /* MPFractionFunction.h */,
 				3B69B67B19E4915E0028E608 /* MPFractionFunction.m */,
-				3B3A4AAC19F71855001E9D54 /* MPRootFunction.h */,
-				3B3A4AAD19F71855001E9D54 /* MPRootFunction.m */,
 			);
 			name = Functions;
 			sourceTree = "<group>";
@@ -492,8 +454,6 @@
 				3B69B66B19DB41B90028E608 /* MPPowerFunctionLayout.m */,
 				3B69B67E19E493630028E608 /* MPFractionFunctionLayout.h */,
 				3B69B67F19E493630028E608 /* MPFractionFunctionLayout.m */,
-				3B3A4AB019F71A11001E9D54 /* MPRootFunctionLayout.h */,
-				3B3A4AB119F71A11001E9D54 /* MPRootFunctionLayout.m */,
 			);
 			name = "Function Layouts";
 			sourceTree = "<group>";
@@ -517,8 +477,6 @@
 				3BFAC39B1997BC7600B3EF67 /* NSString+MPExpressionElement.m */,
 				3B87E35E19009D5F00259938 /* MPFunction.h */,
 				3B87E35F19009D5F00259938 /* MPFunction.m */,
-				3B69B6B719E935E20028E608 /* MPSuffixFunction.h */,
-				3B69B6B819E935E20028E608 /* MPSuffixFunction.m */,
 				3B7B3A1619CC44E4005849E5 /* MPExpressionTokenizer.h */,
 				3B7B3A1719CC44E4005849E5 /* MPExpressionTokenizer.m */,
 				3B7B3A2A19CC467E005849E5 /* MPToken.h */,
@@ -527,6 +485,7 @@
 				3B7B3A5319CC50B1005849E5 /* MPFunction+MPToken.m */,
 				3BB18AA319CDB3A900986DA0 /* MPTokenStream.h */,
 				3BB18AA419CDB3A900986DA0 /* MPTokenStream.m */,
+				3BB09EBC1905EF210080A5ED /* Functions */,
 				3BC46B4F19B506F20033F13A /* Evaluation */,
 			);
 			name = "Base Expression Classes";
@@ -546,14 +505,52 @@
 		3BC46B4F19B506F20033F13A /* Evaluation */ = {
 			isa = PBXGroup;
 			children = (
+				3BF54BB71A18D08400883BFA /* MPExpressionParser.h */,
+				3BF54BB81A18D08400883BFA /* MPExpressionParser.m */,
+				3BEFF74F1A16B06600301C0C /* MPParsedExpression.h */,
+				3BEFF7501A16B06600301C0C /* MPParsedExpression.m */,
+				3BCA0C7E1A12619500C9E3E0 /* MPTerm.h */,
+				3BCA0C7F1A12619500C9E3E0 /* MPTerm.m */,
+				3B9265C51A2147DF00AD2809 /* MPNegatedTerm.h */,
+				3B9265C61A2147DF00AD2809 /* MPNegatedTerm.m */,
+				3BEFF74B1A16A4DA00301C0C /* MPSumTerm.h */,
+				3BEFF74C1A16A4DA00301C0C /* MPSumTerm.m */,
+				3BEFF7531A17AA3200301C0C /* MPProductTerm.h */,
+				3BEFF7541A17AA3200301C0C /* MPProductTerm.m */,
+				3BEFF7601A1804AF00301C0C /* MPFactorialTerm.h */,
+				3BEFF7611A1804AF00301C0C /* MPFactorialTerm.m */,
+				3B69B6BB19E948740028E608 /* MPElementaryFunctionTerm.h */,
+				3B69B6BC19E948740028E608 /* MPElementaryFunctionTerm.m */,
+				3B69B69B19E6F2110028E608 /* MPNumber.h */,
+				3B69B69C19E6F2110028E608 /* MPNumber.m */,
+				3B69B69F19E6F2420028E608 /* MPVariable.h */,
+				3B69B6A019E6F2420028E608 /* MPVariable.m */,
+				3BCA0C831A1405C000C9E3E0 /* MPFunctionTerm.h */,
+				3BCA0C841A1405C000C9E3E0 /* MPFunctionTerm.m */,
 				3B78C85219C2DA5300516335 /* MPEvaluationContext.h */,
 				3B78C85319C2DA5300516335 /* MPEvaluationContext.m */,
 				3B591BB919C58D000061D86B /* MPMathRules.h */,
 				3B591BBA19C58D000061D86B /* MPMathRules.m */,
+				3BEFF75F1A17FF5C00301C0C /* Functions */,
 			);
 			name = Evaluation;
 			sourceTree = "<group>";
 		};
+		3BEFF75F1A17FF5C00301C0C /* Functions */ = {
+			isa = PBXGroup;
+			children = (
+				3BEFF7641A18066300301C0C /* MPSumFunctionTerm.h */,
+				3BEFF7651A18066300301C0C /* MPSumFunctionTerm.m */,
+				3BEFF7681A1807B000301C0C /* MPParenthesisTerm.h */,
+				3BEFF7691A1807B000301C0C /* MPParenthesisTerm.m */,
+				3BEFF76C1A18083C00301C0C /* MPPowerTerm.h */,
+				3BEFF76D1A18083C00301C0C /* MPPowerTerm.m */,
+				3BEFF7701A180C8800301C0C /* MPFractionTerm.h */,
+				3BEFF7711A180C8800301C0C /* MPFractionTerm.m */,
+			);
+			name = Functions;
+			sourceTree = "<group>";
+		};
 		3BF9976218DE623E009CF6C4 = {
 			isa = PBXGroup;
 			children = (
@@ -647,47 +644,46 @@
 			isa = PBXHeadersBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				3B69B6C519E95B250028E608 /* MPOperatorChain.h in Headers */,
 				3B85834C19BB661100D76A8D /* MathKit.h in Headers */,
+				3BEFF76E1A18083C00301C0C /* MPPowerTerm.h in Headers */,
 				3B85833819BB63BD00D76A8D /* MPExpression.h in Headers */,
 				3B85833919BB63C500D76A8D /* MPExpressionElement.h in Headers */,
-				3B69B68D19E6EB0D0028E608 /* MPProduct.h in Headers */,
-				3B69B6B919E935E20028E608 /* MPSuffixFunction.h in Headers */,
 				3B69B67C19E4915E0028E608 /* MPFractionFunction.h in Headers */,
+				3BEFF7551A17AA3200301C0C /* MPProductTerm.h in Headers */,
 				3B78C85419C2DA5300516335 /* MPEvaluationContext.h in Headers */,
 				3B85834419BB654D00D76A8D /* NSString+MPExpressionElement.h in Headers */,
-				3B3A4AAE19F71855001E9D54 /* MPRootFunction.h in Headers */,
+				3BCA0C851A1405C000C9E3E0 /* MPFunctionTerm.h in Headers */,
-				3B69B6B519E88E750028E608 /* MPUnexpectedSymbolValue.h in Headers */,
 				3B7172F219C9FC6700FEAA5B /* MPParenthesisFunctionLayout.h in Headers */,
 				3B52CEDC19BEE63000CEDCFC /* NSRegularExpression+MPParsingAdditions.h in Headers */,
+				3BEFF76A1A1807B000301C0C /* MPParenthesisTerm.h in Headers */,
 				3B85833A19BB63D400D76A8D /* MPFunction.h in Headers */,
-				3B69B6B119E8175F0028E608 /* MPFactor.h in Headers */,
 				3B69B66C19DB41B90028E608 /* MPPowerFunctionLayout.h in Headers */,
-				3B69B69719E6F0780028E608 /* MPValueGroup.h in Headers */,
-				3B3A4AB219F71A11001E9D54 /* MPRootFunctionLayout.h in Headers */,
 				3B85834319BB653700D76A8D /* MPSumFunction.h in Headers */,
+				3BCA0C801A12619500C9E3E0 /* MPTerm.h in Headers */,
 				3B85834119BB651E00D76A8D /* MPRangePath.h in Headers */,
-				3B69B6C119E953590028E608 /* MPFactorial.h in Headers */,
 				3B69B69D19E6F2110028E608 /* MPNumber.h in Headers */,
 				3B85834519BB655200D76A8D /* NSIndexPath+MPAdditions.h in Headers */,
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 				3B7172EE19C9FA8E00FEAA5B /* MPParenthesisFunction.h in Headers */,
+				3BF54BB91A18D08400883BFA /* MPExpressionParser.h in Headers */,
+				3BEFF7511A16B06600301C0C /* MPParsedExpression.h in Headers */,
+				3BEFF7721A180C8800301C0C /* MPFractionTerm.h in Headers */,
 				3B85834619BB655C00D76A8D /* MPExpressionView.h in Headers */,
 				3B85834719BB655F00D76A8D /* MPExpressionStorage.h in Headers */,
+				3B9265C71A2147DF00AD2809 /* MPNegatedTerm.h in Headers */,
 				3BB18AA519CDB3A900986DA0 /* MPTokenStream.h in Headers */,
 				3BF59AFE19D80ECC00E54292 /* MPFunctionsViewController.h in Headers */,
 				3B7B3A2C19CC467E005849E5 /* MPToken.h in Headers */,
-				3B69B68919E6E9280028E608 /* MPSummand.h in Headers */,
 				3B7B3A1819CC44E4005849E5 /* MPExpressionTokenizer.h in Headers */,
-				3B69B69019E6ED6E0028E608 /* MPExpressionTreeElement.h in Headers */,
 				3BF59B0319D81EE600E54292 /* MPWhiteView.h in Headers */,
 				3B85834819BB65B600D76A8D /* MPLayout.h in Headers */,
-				3B69B6A919E6F2AF0028E608 /* MPFunction+MPValue.h in Headers */,
+				3BEFF7661A18066300301C0C /* MPSumFunctionTerm.h in Headers */,
-				3B69B68519E6E8B20028E608 /* MPExpressionTree.h in Headers */,
 				3B85834919BB65B600D76A8D /* MPExpressionLayout.h in Headers */,
+				3BEFF7621A1804AF00301C0C /* MPFactorialTerm.h in Headers */,
 				3B7B3A5419CC50B1005849E5 /* MPFunction+MPToken.h in Headers */,
-				3B69B6BD19E948740028E608 /* MPFunctionValue.h in Headers */,
+				3B69B6BD19E948740028E608 /* MPElementaryFunctionTerm.h in Headers */,
 				3B591BBB19C58D000061D86B /* MPMathRules.h in Headers */,
+				3BEFF74D1A16A4DA00301C0C /* MPSumTerm.h in Headers */,
 				3B69B68019E493630028E608 /* MPFractionFunctionLayout.h in Headers */,
 				3B69B6A119E6F2420028E608 /* MPVariable.h in Headers */,
 				3B85834A19BB65B600D76A8D /* MPFunctionLayout.h in Headers */,
@@ -859,47 +855,47 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				3BEFF76F1A18083C00301C0C /* MPPowerTerm.m in Sources */,
 				3B5FF73C19DB2FF500C8348A /* MPPowerFunction.m in Sources */,
 				3BBEA94219BB79A700133766 /* MPExpressionLayout.m in Sources */,
+				3BF54BBA1A18D08400883BFA /* MPExpressionParser.m in Sources */,
 				3B7B3A1919CC44E4005849E5 /* MPExpressionTokenizer.m in Sources */,
 				3B591BBC19C58D000061D86B /* MPMathRules.m in Sources */,
-				3B69B6BE19E948740028E608 /* MPFunctionValue.m in Sources */,
+				3B69B6BE19E948740028E608 /* MPElementaryFunctionTerm.m in Sources */,
 				3B7172EF19C9FA8E00FEAA5B /* MPParenthesisFunction.m in Sources */,
 				3B7B3A5519CC50B1005849E5 /* MPFunction+MPToken.m in Sources */,
+				3B9265C81A2147DF00AD2809 /* MPNegatedTerm.m in Sources */,
 				3BBEA94119BB79A700133766 /* MPLayout.m in Sources */,
-				3B69B6B219E8175F0028E608 /* MPFactor.m in Sources */,
-				3B69B6BA19E935E20028E608 /* MPSuffixFunction.m in Sources */,
 				3BBEA93D19BB79A700133766 /* NSString+MPExpressionElement.m in Sources */,
 				3B69B68119E493630028E608 /* MPFractionFunctionLayout.m in Sources */,
-				3B69B68619E6E8B20028E608 /* MPExpressionTree.m in Sources */,
 				3BF59B0419D81EE600E54292 /* MPWhiteView.m in Sources */,
 				3BBEA94019BB79A700133766 /* MPExpressionStorage.m in Sources */,
 				3BBEA93F19BB79A700133766 /* MPExpressionView.m in Sources */,
-				3B69B6AA19E6F2AF0028E608 /* MPFunction+MPValue.m in Sources */,
 				3B7B3A2D19CC467E005849E5 /* MPToken.m in Sources */,
-				3B69B6C619E95B250028E608 /* MPOperatorChain.m in Sources */,
 				3B78C85519C2DA5300516335 /* MPEvaluationContext.m in Sources */,
 				3B69B6A219E6F2420028E608 /* MPVariable.m in Sources */,
-				3B69B69819E6F0780028E608 /* MPValueGroup.m in Sources */,
 				3BBEA94419BB79A700133766 /* MPSumFunctionLayout.m in Sources */,
-				3B69B6C219E953590028E608 /* MPFactorial.m in Sources */,
 				3B69B69E19E6F2110028E608 /* MPNumber.m in Sources */,
+				3BEFF7521A16B06600301C0C /* MPParsedExpression.m in Sources */,
 				3B7172F319C9FC6700FEAA5B /* MPParenthesisFunctionLayout.m in Sources */,
-				3B3A4AB319F71A11001E9D54 /* MPRootFunctionLayout.m in Sources */,
+				3BEFF76B1A1807B000301C0C /* MPParenthesisTerm.m in Sources */,
+				3BEFF7631A1804AF00301C0C /* MPFactorialTerm.m in Sources */,
+				3BEFF7731A180C8800301C0C /* MPFractionTerm.m in Sources */,
+				3BEFF7671A18066300301C0C /* MPSumFunctionTerm.m in Sources */,
 				3BBEA93A19BB79A700133766 /* MPSumFunction.m in Sources */,
 				3BBEA93E19BB79A700133766 /* NSIndexPath+MPAdditions.m in Sources */,
 				3B52CEDD19BEE63000CEDCFC /* NSRegularExpression+MPParsingAdditions.m in Sources */,
+				3BEFF7561A17AA3200301C0C /* MPProductTerm.m in Sources */,
 				3B69B67D19E4915E0028E608 /* MPFractionFunction.m in Sources */,
-				3B69B68E19E6EB0D0028E608 /* MPProduct.m in Sources */,
+				3BEFF74E1A16A4DA00301C0C /* MPSumTerm.m in Sources */,
-				3B69B6B619E88E750028E608 /* MPUnexpectedSymbolValue.m in Sources */,
 				3BF59AFF19D80ECC00E54292 /* MPFunctionsViewController.m in Sources */,
+				3BCA0C861A1405C000C9E3E0 /* MPFunctionTerm.m in Sources */,
 				3BB18AA619CDB3A900986DA0 /* MPTokenStream.m in Sources */,
+				3BCA0C811A12619500C9E3E0 /* MPTerm.m in Sources */,
 				3B69B66D19DB41B90028E608 /* MPPowerFunctionLayout.m in Sources */,
 				3BBEA93619BB79A700133766 /* MPFunction.m in Sources */,
-				3B3A4AAF19F71855001E9D54 /* MPRootFunction.m in Sources */,
 				3BBEA93519BB79A700133766 /* MPExpression.m in Sources */,
 				3BBEA93B19BB79A700133766 /* MPRangePath.m in Sources */,
-				3B69B68A19E6E9280028E608 /* MPSummand.m in Sources */,
 				3BBEA94319BB79A700133766 /* MPFunctionLayout.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

MathPad/Base.lproj/MainMenu.xib

@@ -1,7 +1,8 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="6245" systemVersion="13F34" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES">
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="6250" systemVersion="14B25" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES">
     <dependencies>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="6245"/>
+        <deployment identifier="macosx"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="6250"/>
     </dependencies>
     <objects>
         <customObject id="-2" userLabel="File's Owner" customClass="NSApplication"/>

MathPad/MPExpressionTree.h

@@ -1,79 +0,0 @@
-//
-//  MPExpressionTree.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPExpressionTreeElement.h"
-
-
-
-@class MPExpressionTree;
-
-
-/*!
-    @class      MPExpressionTree
-    @brief      The @c MPExpressionTree class is the main interface for working
-                with the mathematical representation of an expression.
- 
-    @discussion Expressions are represented as a tree structure of elements (all
-                of which must conform to the @c MPExpressionTreeElement
-                protocol). Most messages sent to instances of the @c
-                MPExpressionTree class are cascaded down different parts of an
-                expression in some way.
- */
-@interface MPExpressionTree : NSObject <MPExpressionTreeElement>
-
-/*!
-    @property   definedVariable
-    @brief      The variable this expression defines.
- 
-    @discussion A variable definition must be at the beginning of an expression.
-                If it defines a variable it must start with a single letter
-                followed by an equals sign. The single letter is the name of the
-                variable that is defined.
- */
-@property (nonatomic, copy) NSString *definedVariable;
-
-
-/*!
-    @property   summands
-    @brief      The summands that make up the receiver.
- 
-    @discussion A expression mathematically can be interpreted as a series of
-                summands. Summands are the different pars of an expression that
-                are separated by + or - symbols. Every object in the returned
-                array is guaranteed to conform to the @c MPExpressionTreeElement
-                protocol.
- */
-@property (readonly, nonatomic, strong) NSArray *summands;
-
-
-/*!
-    @method     validateExpectingVariableDefinition:error:
-    @brief      Validates the receiver.
- 
-    @discussion Using this method you can validate an expression that contains a
-                variable definition. If a variable definition is expected but not
-                found this method returns @c NO. Likewise @c NO is returned if
-                you do not expect a variable definition but one is found.
- 
-    @param      flag
-                Specifies wether or not to expect a variable definition at the
-                beginning of the expression.
- 
-    @param      error
-                If there is a syntax error in the receiver this parameter will be
-                set to an appropriate value. If you are not interested in the
-                type of syntax error pass @c NULL.
- 
-    @return     @c YES if the receiver is valid, @c NO otherwise. If @c NO is
-                returned the @c error parameter should be set to an appropriate
-                value.
- */
-- (BOOL)validateExpectingVariableDefinition:(BOOL)flag
-                                      error:(NSError *__autoreleasing *)error;
-
-@end

MathPad/MPExpressionTree.m

@@ -1,125 +0,0 @@
-//
-//  MPExpressionTree.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPExpressionTree.h"
-
-#import "MPSummand.h"
-
-#import "MPTokenStream.h"
-#import "MPToken.h"
-
-#import "MPExpression.h"
-
-
-
-@implementation MPExpressionTree {
-    NSMutableArray *_summands;
-}
-
-- (id)init
-{
-    self = [super init];
-    if (self) {
-        _summands = [[NSMutableArray alloc] init];
-    }
-    return self;
-}
-
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    self = [self init];
-    if (self) {
-        [tokenStream beginIgnoringWhitespaceTokens];
-        
-        self.definedVariable = nil;
-        if (tokenStream.currentToken.tokenType == MPVariableToken) {
-            if (tokenStream.peekNextToken.tokenType == MPEqualsToken) {
-                self.definedVariable = tokenStream.currentToken.stringValue;
-                [tokenStream currentTokenConsumed];
-                [tokenStream currentTokenConsumed];
-            }
-        }
-        while ([tokenStream hasMoreTokens]) {
-            [_summands addObject:[[MPSummand alloc] initWithTokenStream:tokenStream]];
-        }
-        
-        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-    }
-    return self;
-}
-
-
-- (NSArray *)summands
-{
-    return _summands;
-}
-
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    return [self validateExpectingVariableDefinition:NO
-                                               error:error];
-}
-
-
-- (BOOL)validateExpectingVariableDefinition:(BOOL)flag
-                                      error:(NSError *__autoreleasing *)error
-{
-    if (flag) {
-        if (!self.definedVariable) {
-            if (error) {
-                *error = MPParseError(1,
-                                      NSLocalizedString(@"Expected Variable Definition.", @"Error message. This is displayed when an expected variable definition was not found."),
-                                      nil);
-            }
-            return NO;
-        }
-    } else {
-        if (self.definedVariable) {
-            if (error) {
-                *error = MPParseError(2,
-                                      NSLocalizedString(@"Unexpected Variable Definition.", @"Error message. This is displayed when no variable definition was expected but one was found."),
-                                      nil);
-            }
-            return NO;
-        }
-    }
-    if (_summands.count == 0) {
-        if (error) {
-            *error = MPParseError(3,
-                                  NSLocalizedString(@"Empty Expression.", @"Error message. This is displayed when the user tried to evaluate an empty expression."),
-                                  nil);
-        }
-        return NO;
-    }
-    for (MPSummand *summand in _summands) {
-        if (![summand validate:error]) {
-            return NO;
-        }
-    }
-    return YES;
-}
-
-
-- (NSDecimalNumber *)evaluate
-{
-    NSDecimalNumber *value = [NSDecimalNumber zero];
-    for (MPSummand *summand in _summands) {
-        NSDecimalNumber *currentValue = [summand evaluate];
-        if ([currentValue isEqualToNumber:[NSDecimalNumber notANumber]]) {
-            value = currentValue;
-            break;
-        }
-        value = [value decimalNumberByAdding:currentValue];
-    }
-    return value;
-}
-
-
-@end

MathPad/MPExpressionTreeElement.h

@@ -1,89 +0,0 @@
-//
-//  MPExpressionTreeElement.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-// TODO: Replace internal inconsistency exception with something else
-
-
-
-@class MPTokenStream;
-
-
-/*!
-    @protocol   MPExpressionTreeElement
-    @brief      This protocol defines the methods that are essential for dealing
-                with an expression in a mathematical context.
- 
-    @discussion Dealing with an expression in a mathematical context involves
-                anything from evaluation to transformation of expressions and
-                equations.
- */
-@protocol MPExpressionTreeElement <NSObject>
-@required
-
-
-/*!
-    @method     initWithTokenStream:
-    @brief      Initializes the expression tree element from the given token
-                strem.
- 
-    @discussion This method consumes the tokens that make up this element. If the
-                token stream does not start with a token that is appropriate for
-                the initializied expression tree element a @c
-                NSInternalInconsistency exception is raised.
- 
-    @param      tokenStream
-                The token stream the receiver is to be initialized from.
- 
-    @return     A new instance.
- */
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream;
-
-
-/*!
-    @method     validate:
-    @brief      Validates the receiver.
- 
-    @discussion Validation should only check for syntax errors. Mathematical
-                errors like a division by @c 0 should be handled with in @c
-                -evaluate.
- 
-    @param      error
-                If there is a syntax error in the receiver this parameter should
-                be set to an appropriate value. If you are not interested in the
-                type of syntax error pass @c NULL.
- 
-    @return     @c YES if the receiver is valid, @c NO otherwise. If @c NO is
-                returned the @c error parameter should be set to an appropriate
-                value.
- */
-- (BOOL)validate:(NSError *__autoreleasing *)error;
-
-
-/*!
-    @method     evaluate:
-    @brief      Evaluates the receiver.
- 
-    @discussion Evaluation does not take syntax errors into account. Before this
-                method is called you must call @c validate: to make sure that the
-                reciever is valid for evaluation. The result of evaluation with
-                @c -validate: returning @c NO may be unexpected or evaluation may
-                completely fail.
- 
-    @param      error
-                If any errors occur during evaluation (such as division by zero)
-                this parameter will be set to an appropriate value. If you are
-                not interested in errors pass @c NULL.
-       @warning This method is not responsible for syntax validation. Use @c
-                -validate: instead.
- 
-    @return     The result of the evaluationa or @c nil or @c NaN if evaluation
-                fails. If evaluation fails the @c error parameter will be set to
-                an apporpriate value.
- */
-- (NSDecimalNumber *)evaluate:(NSError *__autoreleasing *)error;
-
-@end

MathPad/MPFactor.h

@@ -1,20 +0,0 @@
-//
-//  MPFactor.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPExpressionTreeElement.h"
-
-@class MPFactor, MPOperatorChain;
-@protocol MPValue;
-
-@interface MPFactor : NSObject <MPExpressionTreeElement>
-
-@property (readonly, nonatomic) BOOL hasMultiplicationSymbol;
-@property (readonly, nonatomic, strong) MPOperatorChain *operatorChain;
-@property (readonly, nonatomic, strong) id<MPValue> value;
-
-@end

MathPad/MPFactor.m

@@ -1,80 +0,0 @@
-//
-//  MPFactor.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPFactor.h"
-
-#import "MPOperatorChain.h"
-#import "MPValueGroup.h"
-
-#import "MPTokenStream.h"
-#import "MPToken.h"
-
-#import "MPExpression.h"
-#import "MPMathRules.h"
-
-@implementation MPFactor {
-    BOOL _multiplicationSymbolPresent;
-}
-
-- (instancetype)init
-{
-    self = [super init];
-    if (self) {
-        
-    }
-    return self;
-}
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    self = [self init];
-    if (self) {
-        [tokenStream beginIgnoringWhitespaceTokens];
-        MPToken *token = tokenStream.currentToken;
-        _multiplicationSymbolPresent = token.tokenType == MPMultiplicationSymbolToken;
-        if (_multiplicationSymbolPresent) {
-            [tokenStream currentTokenConsumed];
-        }
-        if (tokenStream.currentToken.tokenType == MPOperatorListToken) {
-            _operatorChain = [[MPOperatorChain alloc] initWithTokenStream:tokenStream];
-        }
-        MPValueGroup *valueGroup = [[MPValueGroup alloc] initWithTokenStream:tokenStream];
-        _value = [tokenStream consumeSuffixesForValue:valueGroup];
-        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-    }
-    return self;
-}
-
-- (BOOL)hasMultiplicationSymbol
-{
-    return _multiplicationSymbolPresent;
-}
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    if (self.operatorChain.numberOfOperators > [[MPMathRules sharedRules] maximumOperatorChainLengthInMultiplication]) {
-        if (error) {
-            *error = MPParseError(7,
-                                  NSLocalizedString(@"Too many operators in Multiplication.", @"Error message. This is displayed when there are too many operators between a multiplication symbol and a value."),
-                                  nil);
-        }
-        return NO;
-    }
-    return [self.value validate:error];
-}
-
-- (NSDecimalNumber *)evaluate
-{
-    NSDecimalNumber *value = [self.value evaluate];
-    if ([value isNotEqualTo:[NSDecimalNumber notANumber]] && self.operatorChain) {
-        value = [value decimalNumberByMultiplyingBy:[self.operatorChain evaluate]];
-    }
-    return value;
-}
-
-@end

MathPad/MPFactorial.h

@@ -1,17 +0,0 @@
-//
-//  MPFactorial.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 11.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPValueGroup.h"
-
-@class MPFactorial;
-
-@interface MPFactorial : NSObject <MPValue>
-
-@property (readonly, nonatomic, strong) id<MPValue> value;
-
-@end

MathPad/MPFactorial.m

@@ -1,51 +0,0 @@
-//
-//  MPFactorial.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 11.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPFactorial.h"
-
-#import "MPTokenStream.h"
-#import "MPToken.h"
-
-@implementation MPFactorial
-
-- (instancetype)init
-{
-    self = [super init];
-    if (self) {
-    }
-    return self;
-}
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    self = [self init];
-    if (self) {
-        [tokenStream beginIgnoringWhitespaceTokens];
-        if (tokenStream.currentToken.tokenType != MPFactorialToken) {
-            [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-            return nil;
-        } else {
-            [tokenStream currentTokenConsumed];
-        }
-        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-    }
-    return self;
-}
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    return [self.value validate:error];
-}
-
-- (NSDecimalNumber *)evaluate
-{
-    double value = [self.value evaluate].doubleValue;
-    return [[NSDecimalNumber alloc] initWithDouble:tgamma(value+1)];
-}
-
-@end

MathPad/MPFunction+MPValue.h

@@ -1,14 +0,0 @@
-//
-//  MPFunction+MPValue.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPFunction.h"
-#import "MPValueGroup.h"
-
-@interface MPFunction (MPValue) <MPValue>
-
-@end

MathPad/MPFunction+MPValue.m

@@ -1,28 +0,0 @@
-//
-//  MPFunction+MPValue.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPFunction+MPValue.h"
-
-#import "MPFunction+MPToken.h"
-
-@implementation MPFunction (MPValue)
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    [tokenStream beginIgnoringWhitespaceTokens];
-    if (tokenStream.currentToken.tokenType != MPGenericFunctionToken) {
-        @throw [NSException exceptionWithName:NSInternalInconsistencyException
-                                       reason:@"Expected Function"
-                                     userInfo:nil];
-    }
-    [tokenStream currentTokenConsumed];
-    [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-    return [self init];
-}
-
-@end

MathPad/MPFunctionValue.h

@@ -1,19 +0,0 @@
-//
-//  MPFunctionValue.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 11.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPValueGroup.h"
-
-@class MPFunctionValue, MPPowerFunction, MPValueGroup;
-
-@interface MPFunctionValue : NSObject <MPValue>
-
-@property (readonly, nonatomic, copy) NSString *functionName;
-@property (readonly, nonatomic, strong) MPPowerFunction *power; // May be nil
-@property (readonly, nonatomic, strong) MPValueGroup *valueGroup;
-
-@end

MathPad/MPFunctionValue.m

@@ -1,145 +0,0 @@
-//
-//  MPFunctionValue.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 11.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPFunctionValue.h"
-
-#import "MPTokenStream.h"
-#import "MPToken.h"
-
-#import "MPExpression.h"
-#import "MPMathRules.h"
-
-double defaultFunction(double value) {return value;};
-
-@implementation MPFunctionValue {
-    NSDecimalNumber *(^_function)(NSDecimalNumber *);
-}
-
-- (id)init
-{
-    self = [super init];
-    if (self) {
-        
-    }
-    return self;
-}
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    switch (tokenStream.currentToken.tokenType) {
-        case MPSinToken:
-            [tokenStream currentTokenConsumed];
-            _functionName = @"sin";
-            return [self initWithTokenStream:tokenStream
-                                    function:&sin
-                               takesArcValue:YES
-                             returnsArcValue:NO];
-            
-        case MPCosToken:
-            [tokenStream currentTokenConsumed];
-            _functionName = @"cos";
-            return [self initWithTokenStream:tokenStream
-                                    function:&cos
-                               takesArcValue:YES
-                             returnsArcValue:NO];
-            
-        case MPTanToken:
-            [tokenStream currentTokenConsumed];
-            _functionName = @"tan";
-            return [self initWithTokenStream:tokenStream
-                                    function:&tan
-                               takesArcValue:YES
-                             returnsArcValue:NO];
-            
-        case MPASinToken:
-            [tokenStream currentTokenConsumed];
-            _functionName = @"asin";
-            return [self initWithTokenStream:tokenStream
-                                    function:&asin
-                               takesArcValue:YES
-                             returnsArcValue:NO];
-            
-        case MPACosToken:
-            [tokenStream currentTokenConsumed];
-            _functionName = @"acos";
-            return [self initWithTokenStream:tokenStream
-                                    function:&acos
-                               takesArcValue:YES
-                             returnsArcValue:NO];
-            
-        case MPATanToken:
-            [tokenStream currentTokenConsumed];
-            _functionName = @"atan";
-            return [self initWithTokenStream:tokenStream
-                                    function:&atan
-                               takesArcValue:YES
-                             returnsArcValue:NO];
-
-        default:
-            @throw [NSException exceptionWithName:NSInternalInconsistencyException
-                                           reason:@"Expected Function"
-                                         userInfo:nil];
-            break;
-    }
-    return self;
-}
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-                           function:(double (*)(double))function
-                      takesArcValue:(BOOL)takesArc
-                    returnsArcValue:(BOOL)returnsArc
-{
-    self = [self init];
-    if (self) {
-        _valueGroup = [[MPValueGroup alloc] initWithTokenStream:tokenStream];
-        id __weak weakSelf = self;
-        _function = ^(NSDecimalNumber *value){
-            if (takesArc) {
-                value = [weakSelf convertToRadiantsIfNecessary:value];
-            }
-            NSDecimalNumber *returnValue = [[NSDecimalNumber alloc] initWithDouble:function(value.doubleValue)];
-            if (returnsArc) {
-                returnValue = [weakSelf convertToDegreesIfNecessary:returnValue];
-            }
-            return returnValue;
-        };
-    }
-    return self;
-}
-
-- (NSDecimalNumber *)convertToRadiantsIfNecessary:(NSDecimalNumber *)degrees
-{
-    if ([MPMathRules sharedRules].isUsingDegrees) {
-        // * M_PI / 180
-        return [[degrees decimalNumberByMultiplyingBy:[[NSDecimalNumber alloc] initWithDouble:M_PI]] decimalNumberByDividingBy:[[NSDecimalNumber alloc] initWithInteger:180]];
-    } else {
-        return degrees;
-    }
-}
-
-- (NSDecimalNumber *)convertToDegreesIfNecessary:(NSDecimalNumber *)radiants
-{
-    if ([MPMathRules sharedRules].isUsingDegrees) {
-        // * 180 / M_PI
-        return [[radiants decimalNumberByMultiplyingBy:[[NSDecimalNumber alloc] initWithInteger:180]] decimalNumberByDividingBy:[[NSDecimalNumber alloc] initWithDouble:M_PI]];
-    } else {
-        return radiants;
-    }
-}
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    return [self.valueGroup validate:error];
-}
-
-- (NSDecimalNumber *)evaluate
-{
-    return _function([self.valueGroup evaluate]);
-}
-
-@end

MathPad/MPOperatorChain.h

@@ -1,18 +0,0 @@
-//
-//  MPOperatorChain.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 11.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPExpressionTreeElement.h"
-
-@class MPOperatorChain;
-
-@interface MPOperatorChain : NSObject <MPExpressionTreeElement>
-
-@property (readonly, nonatomic) BOOL negating;
-@property (readonly, nonatomic) NSUInteger numberOfOperators;
-
-@end

MathPad/MPOperatorChain.m

@@ -1,61 +0,0 @@
-//
-//  MPOperatorChain.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 11.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPOperatorChain.h"
-
-#import "MPTokenStream.h"
-#import "MPToken.h"
-
-@implementation MPOperatorChain
-
-- (id)init
-{
-    self = [super init];
-    if (self) {
-    }
-    return self;
-}
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    self = [self init];
-    if (self) {
-        [tokenStream beginIgnoringWhitespaceTokens];
-        MPToken *currentToken = tokenStream.currentToken;
-        
-        if (currentToken.tokenType != MPOperatorListToken) {
-            @throw [NSException exceptionWithName:NSInternalInconsistencyException reason:@"Expected Operators" userInfo:nil];
-        }
-        
-        NSString *operatorString = currentToken.stringValue;
-        operatorString = [[operatorString componentsSeparatedByString:@" "] componentsJoinedByString:@""];
-        _negating = NO;
-        _numberOfOperators = operatorString.length;
-        for (NSUInteger index = 0; index < _numberOfOperators; index++) {
-            if ([[operatorString substringWithRange:NSMakeRange(index, 1)] isEqualToString:@"-"]) {
-                _negating = !_negating;
-            }
-        }
-        
-        [tokenStream currentTokenConsumed];
-        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-    }
-    return self;
-}
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    return YES;
-}
-
-- (NSDecimalNumber *)evaluate
-{
-    return self.negating ? [[NSDecimalNumber alloc] initWithInteger:-1] : [NSDecimalNumber one];
-}
-
-@end

MathPad/MPProduct.h

@@ -1,17 +0,0 @@
-//
-//  MPProduct.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPExpressionTreeElement.h"
-
-@class MPProduct;
-
-@interface MPProduct : NSObject <MPExpressionTreeElement>
-
-@property (readonly, nonatomic, strong) NSArray *factors;
-
-@end

MathPad/MPProduct.m

@@ -1,99 +0,0 @@
-//
-//  MPProduct.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPProduct.h"
-
-#import "MPFactor.h"
-#import "MPValueGroup.h"
-
-#import "MPTokenStream.h"
-#import "MPToken.h"
-
-#import "MPExpression.h"
-
-@implementation MPProduct {
-    NSMutableArray *_factors;
-}
-
-- (id)init
-{
-    self = [super init];
-    if (self) {
-        _factors = [[NSMutableArray alloc] init];
-    }
-    return self;
-}
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    self = [self init];
-    if (self) {
-        [tokenStream beginIgnoringWhitespaceTokens];
-        
-        while ([tokenStream hasMoreTokens] && tokenStream.currentToken.tokenType != MPOperatorListToken) {
-            [_factors addObject:[[MPFactor alloc] initWithTokenStream:tokenStream]];
-        }
-        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-    }
-    return self;
-}
-
-- (NSArray *)factors
-{
-    return _factors;
-}
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    if (_factors.count == 0) {
-        if (error) {
-            *error = MPParseError(5,
-                                  NSLocalizedString(@"Expected A Value.", @"Error message. Displayed when a value was expected in an expression but none was found."),
-                                  nil);
-        }
-        return NO;
-    }
-    MPFactor *factor = _factors[0];
-    if (factor.hasMultiplicationSymbol) {
-        if (error) {
-            *error = MPParseError(6,
-                                  NSLocalizedString(@"Unexpected Symbol.", @"Error message. Displayed when or inappropriate symbol was encountered during parsing."),
-                                  nil);
-        }
-        return NO;
-    }
-    if (![factor.value validate:error]) {
-        return NO;
-    }
-    for (NSUInteger index = 1; index < _factors.count; index++) {
-        factor = _factors[index];
-        if (![factor validate:error]) {
-            return NO;
-        }
-    }
-    return YES;
-}
-
-- (NSDecimalNumber *)evaluate
-{
-    NSDecimalNumber *value = [NSDecimalNumber one];
-    for (MPFactor *factor in _factors) {
-        NSDecimalNumber *currentValue = [factor evaluate];
-        if ([currentValue isEqualToNumber:[NSDecimalNumber notANumber]]) {
-            value = currentValue;
-            break;
-        }
-        value = [value decimalNumberByMultiplyingBy:currentValue];
-        if ([value compare:@(0)] == NSOrderedSame) {
-            break;
-        }
-    }
-    return value;
-}
-
-@end

MathPad/MPRootFunction.h

@@ -1,18 +0,0 @@
-//
-//  MPRootFunction.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 22.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPFunction.h"
-
-@class MPRootFunction, MPExpression;
-
-@interface MPRootFunction : MPFunction
-
-@property (nonatomic, strong) MPExpression *exponentExpression;
-@property (nonatomic, strong) MPExpression *radicantExpression;
-
-@end

MathPad/MPRootFunction.m

@@ -1,44 +0,0 @@
-//
-//  MPRootFunction.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 22.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPRootFunction.h"
-
-#import "MPExpression.h"
-#import "MPExpressionTree.h"
-
-@implementation MPRootFunction
-
-MPFunctionAccessorImplementation(ExponentExpression, _exponentExpression)
-MPFunctionAccessorImplementation(RadicantExpression, _radicantExpression)
-
-- (NSArray *)childrenAccessors
-{
-    return @[@"exponentExpression", @"radicantExpression"];
-}
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    return [[self.exponentExpression parse] validate:error] && [[self.radicantExpression parse] validate:error];
-}
-
-- (NSDecimalNumber *)evaluate
-{
-    NSDecimalNumber *exponent = [[self.exponentExpression parse] evaluate];
-    NSDecimalNumber *radicant = [[self.radicantExpression parse] evaluate];
-    return [[NSDecimalNumber alloc] initWithDouble:pow(radicant.doubleValue, exponent.doubleValue)];
-}
-
-- (NSString *)description
-{
-    if (self.exponentExpression == nil) {
-        return [NSString stringWithFormat:@"√%@", self.radicantExpression.description];
-    }
-    return [NSString stringWithFormat:@"pow(%@; %@)", self.radicantExpression.description, self.exponentExpression];
-}
-
-@end

MathPad/MPRootFunctionLayout.h

@@ -1,19 +0,0 @@
-//
-//  MPRootFunctionLayout.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 22.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPFunctionLayout.h"
-
-@class MPRootFunctionLayout, MPRootFunction;
-
-@interface MPRootFunctionLayout : MPFunctionLayout
-
-- (MPRootFunction *)rootFunction;
-
-@property (nonatomic, getter=isExponentImplicit) BOOL exponentImplicit;
-
-@end

MathPad/MPRootFunctionLayout.m

@@ -1,84 +0,0 @@
-//
-//  MPRootFunctionLayout.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 22.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPRootFunctionLayout.h"
-
-#import "MPRootFunction.h"
-
-#define kRootFunctionSpaceBetweenRadicantAndExponent 5
-
-@implementation MPRootFunctionLayout
-
-- (MPRootFunction *)rootFunction
-{
-    return (MPRootFunction *)self.function;
-}
-
-- (NSUInteger)indexOfLeadingChild
-{
-    return 0;
-}
-
-- (NSUInteger)indexOfTrailingChild
-{
-    return 1;
-}
-
-- (NSUInteger)indexOfChildAfterChildAtIndex:(NSUInteger)index
-{
-    return index == 0 ? 1 : [super indexOfChildAfterChildAtIndex:index];
-}
-
-- (NSUInteger)indexOfChildBeforeChildAtIndex:(NSUInteger)index
-{
-    return index == 1 ? 0 : [super indexOfChildBeforeChildAtIndex:index];
-}
-
-- (NSUInteger)indexOfChildBelowChildAtIndex:(NSUInteger)index
-{
-    return 1;
-}
-
-- (NSUInteger)indexOfChildAboveChildAtIndex:(NSUInteger)index
-{
-    return 0;
-}
-
-- (NSIndexSet *)indexesOfRemainingChildren
-{
-    return [NSIndexSet indexSetWithIndex:1];
-}
-
-- (NSPoint)offsetOfChildLayoutAtIndex:(NSUInteger)index
-{
-    NSRect exponentBounds = [self childLayoutAtIndex:0].bounds;
-    NSRect radicandBounds = [self childLayoutAtIndex:1].bounds;
-    if (index == 0) {
-        return NSMakePoint(0, (radicandBounds.size.height + radicandBounds.origin.y) / 2);
-    } else {
-        
-        return NSMakePoint(exponentBounds.size.width + kRootFunctionSpaceBetweenRadicantAndExponent, 0);
-    }
-}
-
-- (BOOL)childAtIndexUsesSmallSize:(NSUInteger)index
-{
-    return index == 0;
-}
-
-- (NSRect)generateBounds
-{
-    return NSZeroRect;
-}
-
-- (void)draw
-{
-    
-}
-
-@end

MathPad/MPSuffixFunction.h

@@ -1,44 +0,0 @@
-//
-//  MPSuffixFunction.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 11.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPFunction.h"
-
-
-
-@class MPSuffixFunction;
-@protocol MPValue;
-
-
-/*!
-    @class      MPSuffixFunction
-    @brief      This is the common superclass for all functions that apply to the
-                value preceeding them.
- 
-    @discussion One example for a suffix function is a power. Powers apply to a
-                base value and are evaluated with very high priority. In fact the
-                base value may not be used without previously having evaluated
-                the suffix function.
- 
-                Another special thing about suffix functions is that they need to
-                know more than their own children (namely the base value) to be
-                evaluated. To be able to do this suffix functions have a special
-                property @c baseValue that is set before the function is
-                evaluated.
- */
-@interface MPSuffixFunction : MPFunction
-
-/*!
-    @property   baseValue
-    @brief      The receiver's base value.
- 
-    @discussion The base value is the thing a suffix function applies to (e.g.
-                a power's base).
- */
-@property (nonatomic, strong) id<MPValue> baseValue;
-
-@end

MathPad/MPSuffixFunction.m

@@ -1,15 +0,0 @@
-//
-//  MPSuffixFunction.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 11.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPSuffixFunction.h"
-
-
-
-@implementation MPSuffixFunction
-
-@end

MathPad/MPSummand.h

@@ -1,42 +0,0 @@
-//
-//  MPSummand.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPExpressionTreeElement.h"
-
-
-
-@class MPSummand, MPOperatorChain, MPProduct;
-
-
-/*!
-    @class      MPSummand
-    @brief      A summand is a part of an expression that consists of a list of
-                addition and subtraction operators and a product.
- */
-@interface MPSummand : NSObject <MPExpressionTreeElement>
-
-
-/*!
-    @property   operatorChain
-    @brief      The summand's preceeding operators.
- 
-    @discussion The operator chain is interpreted as a factor for the @c product
-                property of the summand during evaluation.
- */
-@property (readonly, nonatomic, strong) MPOperatorChain *operatorChain;
-
-
-/*!
-    @property   product
-    @brief      The summand's product.
- 
-    @discussion The product is the @em value of a summand.
- */
-@property (readonly, nonatomic, strong) MPProduct *product;
-
-@end

MathPad/MPSummand.m

@@ -1,66 +0,0 @@
-//
-//  MPSummand.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPSummand.h"
-
-#import "MPOperatorChain.h"
-#import "MPProduct.h"
-
-#import "MPTokenStream.h"
-#import "MPToken.h"
-
-#import "MPExpression.h"
-#import "MPMathRules.h"
-
-@implementation MPSummand
-
-- (id)init
-{
-    self = [super init];
-    if (self) {
-    }
-    return self;
-}
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    self = [self init];
-    if (self) {
-        [tokenStream beginIgnoringWhitespaceTokens];
-        if (tokenStream.currentToken.tokenType == MPOperatorListToken) {
-            _operatorChain = [[MPOperatorChain alloc] initWithTokenStream:tokenStream];
-        }
-        _product = [[MPProduct alloc] initWithTokenStream:tokenStream];
-        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-    }
-    return self;
-}
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    if (self.operatorChain.numberOfOperators > [MPMathRules sharedRules].maximumOperatorChainLength) {
-        if (error) {
-            *error = MPParseError(4,
-                                  NSLocalizedString(@"Too many operators.", @"Error message. This is displayed when there are too many subsequent operators in an expression."),
-                                  nil);
-        }
-        return NO;
-    }
-    return [self.product validate:error];
-}
-
-- (NSDecimalNumber *)evaluate
-{
-    NSDecimalNumber *value = [self.product evaluate];
-    if ([value isNotEqualTo:[NSDecimalNumber notANumber]] && self.operatorChain) {
-        value = [value decimalNumberByMultiplyingBy:[self.operatorChain evaluate]];
-    }
-    return value;
-}
-
-@end

MathPad/MPUnexpectedSymbolValue.h

@@ -1,17 +0,0 @@
-//
-//  MPUnidentifiedSymbolValue.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 11.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPValueGroup.h"
-
-@class MPUnexpectedSymbolValue;
-
-@interface MPUnexpectedSymbolValue : NSObject <MPValue>
-
-@property (readonly, nonatomic, copy) NSString *symbol;
-
-@end

MathPad/MPUnexpectedSymbolValue.m

@@ -1,58 +0,0 @@
-//
-//  MPUnidentifiedSymbolValue.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 11.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPUnexpectedSymbolValue.h"
-
-#import "MPTokenStream.h"
-#import "MPToken.h"
-
-#import "MPExpression.h"
-
-@implementation MPUnexpectedSymbolValue
-
-- (instancetype)init
-{
-    self = [super init];
-    if (self) {
-    }
-    return self;
-}
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    self = [self init];
-    if (self) {
-        [tokenStream beginIgnoringWhitespaceTokens];
-        _symbol = tokenStream.currentToken.stringValue;
-        [tokenStream currentTokenConsumed];
-        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-    }
-    return self;
-}
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    if (error) {
-        *error = MPParseError(10,
-                              NSLocalizedString(@"Unknown Symbol.", @"Error message. Displayed when an unknown symbol was encountered during parsing."),
-                              nil);
-    }
-    return NO;
-}
-
-- (NSDecimalNumber *)evaluate
-{
-    return [NSDecimalNumber notANumber];
-}
-
-- (NSArray *)expressionElements
-{
-    return @[self.symbol];
-}
-
-@end

MathPad/MPValueGroup.h

@@ -1,31 +0,0 @@
-//
-//  MPValueGroup.h
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPExpressionTreeElement.h"
-#import "MPTokenStream.h"
-
-@class MPValueGroup;
-@protocol MPValue;
-
-@protocol MPValue <MPExpressionTreeElement>
-
-@end
-
-
-@interface MPValueGroup : NSObject <MPValue>
-
-@property (readonly, nonatomic, strong) NSArray *values;
-
-@end
-
-
-@interface MPTokenStream (MPValueSuffixes)
-
-- (id<MPValue>)consumeSuffixesForValue:(id<MPValue>)value;
-
-@end

MathPad/MPValueGroup.m

@@ -1,162 +0,0 @@
-//
-//  MPValueGroup.m
-//  MathPad
-//
-//  Created by Kim Wittenburg on 09.10.14.
-//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
-//
-
-#import "MPValueGroup.h"
-
-#import "MPNumber.h"
-#import "MPVariable.h"
-#import "MPFunctionValue.h"
-#import "MPUnexpectedSymbolValue.h"
-#import "MPFactorial.h"
-
-#import "MPTokenStream.h"
-#import "MPToken.h"
-
-#import "MPExpression.h"
-#import "MPSuffixFunction.h"
-
-@implementation MPValueGroup {
-    NSMutableArray *_values;
-}
-
-- (id)init
-{
-    self = [super init];
-    if (self) {
-        _values = [[NSMutableArray alloc] init];
-    }
-    return self;
-}
-
-- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
-{
-    self = [self init];
-    if (self) {
-        [tokenStream beginIgnoringWhitespaceTokens];
-        [tokenStream currentToken];  // This will skip leading whitespaces
-        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-        [tokenStream beginAcceptingWhitespaceTokens];
-        
-        BOOL checkMoreTokens = YES;
-        while (tokenStream.currentToken.tokenType != MPWhitespaceToken && checkMoreTokens) {
-            id<MPValue> currentValue;
-            switch (tokenStream.currentToken.tokenType) {
-                case MPNumberToken:
-                {
-                    currentValue = [[MPNumber alloc] initWithTokenStream:tokenStream];
-                }
-                    break;
-                    
-                case MPVariableToken:
-                {
-                    currentValue = [[MPVariable alloc] initWithTokenStream:tokenStream];
-                }
-                    break;
-                    
-                case MPGenericFunctionToken:
-                {
-                    currentValue = (id<MPValue>)tokenStream.currentToken;
-                    if ([currentValue isKindOfClass:[MPSuffixFunction class]]) {
-                        ((MPSuffixFunction *)currentValue).baseValue = nil;
-                    }
-                    [tokenStream currentTokenConsumed];
-                }
-                    break;
-                    
-                case MPSinToken:
-                case MPCosToken:
-                case MPTanToken:
-                case MPASinToken:
-                case MPACosToken:
-                case MPATanToken:
-                {
-                    currentValue = [[MPFunctionValue alloc] initWithTokenStream:tokenStream];
-                }
-                    break;
-                    
-                case MPUnidentifiedToken:
-                case MPEqualsToken:
-                    currentValue = [[MPUnexpectedSymbolValue alloc] initWithTokenStream:tokenStream];
-                    break;
-                    
-                default:
-                    checkMoreTokens = NO;
-                    break;
-            }
-            if (checkMoreTokens) {
-                [_values addObject:[tokenStream consumeSuffixesForValue:currentValue]];
-            }
-        }
-        
-        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
-    }
-    return self;
-}
-
-- (BOOL)validate:(NSError *__autoreleasing *)error
-{
-    if (_values.count == 0) {
-        if (error) {
-            *error = MPParseError(8,
-                                  NSLocalizedString(@"Expected Value.", @"Error message. This is displayed when a value was expected but none was found."),
-                                  nil);
-        }
-        return NO;
-    }
-    for (id<MPValue> value in _values) {
-        if (![value validate:error]) {
-            return NO;
-        }
-    }
-    return YES;
-}
-
-- (NSDecimalNumber *)evaluate
-{
-    NSDecimalNumber *result = [NSDecimalNumber one];
-    for (id<MPValue> value in _values) {
-        NSDecimalNumber *currentValue = [value evaluate];
-        if ([currentValue isEqualToNumber:[NSDecimalNumber notANumber]]) {
-            result = currentValue;
-            break;
-        }
-        result = [result decimalNumberByMultiplyingBy:currentValue];
-        if ([result compare:@(0)] == NSOrderedSame) {
-            break;
-        }
-    }
-    return result;
-}
-
-@end
-
-
-@implementation MPTokenStream (MPValueSuffixes)
-
-- (id<MPValue>)consumeSuffixesForValue:(id<MPValue>)value
-{
-    BOOL repeat = YES;
-    while (repeat) {
-        if (self.currentToken.tokenType == MPFactorialToken) {
-            MPFactorial *factorial = [[MPFactorial alloc] init];
-            factorial.value = value;
-            value = factorial;
-            [self currentTokenConsumed];
-        } else if (self.currentToken.tokenType == MPGenericFunctionToken && [self.currentToken isKindOfClass:[MPSuffixFunction class]]) {
-            MPSuffixFunction *token = (MPSuffixFunction *)self.currentToken;
-            token.baseValue = value;
-            value = token;
-            [self currentTokenConsumed];
-        } else {
-            repeat = NO;
-        }
-    }
-    return value;
-}
-
-@end