From 2163f24509e512c2b5b2dd253075d067cca6db94 Mon Sep 17 00:00:00 2001
From: Kim Wittenburg <Kim.Wittenburg@me.com>
Date: Wed, 23 Apr 2014 03:11:07 +0200
Subject: [PATCH] Renamed MPRange to MPRangePath Added MPRangeExtension
 Category on MPExpression

---
 MathPad/MPRangePath.h |  47 +++++++++++++
 MathPad/MPRangePath.m | 153 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 200 insertions(+)
 create mode 100644 MathPad/MPRangePath.h
 create mode 100644 MathPad/MPRangePath.m

diff --git a/MathPad/MPRangePath.h b/MathPad/MPRangePath.h
new file mode 100644
index 0000000..cdc101d
--- /dev/null
+++ b/MathPad/MPRangePath.h
@@ -0,0 +1,47 @@
+//
+//  MPRange.h
+//  MathPad
+//
+//  Created by Kim Wittenburg on 18.04.14.
+//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
+//
+
+#import "MPExpression.h"
+
+@interface MPRangePath : NSObject <NSCopying, NSCoding>
+
+#pragma mark Creation Methods
+
+- (instancetype)init;
+- (instancetype)initWithLocation:(NSIndexPath *)location
+                          length:(NSUInteger)length;
+- (instancetype)initWithRange:(NSRange)aRange;
+
++ (instancetype)emptyRangePath;
++ (instancetype)rangePathWithLocation:(NSIndexPath *)location
+                           length:(NSUInteger)length;
++ (instancetype)rangePathWithRange:(NSRange)aRange;
+
+#pragma mark Properties
+
+@property (nonatomic, strong) NSIndexPath *location;
+@property (nonatomic) NSUInteger length;
+
+- (NSIndexPath *)maxRangePath;
+- (NSRange)rangeAtLastIndex;
+
+#pragma mark Working with Ranges
+
+- (BOOL)containsRangePath:(MPRangePath *)aRangePath;
+- (BOOL)containsLocation:(NSIndexPath *)location;
+
+- (BOOL)isEqual:(id)object;
+- (BOOL)isEqualToRangePath:(MPRangePath *)aRangePath;
+
+@end
+
+@interface MPExpression (MPRangeExtension)
+
+- (MPExpression *)subexpressionWithRangePath:(MPRangePath *)aRangePath; // If location points to expression (in function) nil is returned
+
+@end
diff --git a/MathPad/MPRangePath.m b/MathPad/MPRangePath.m
new file mode 100644
index 0000000..e498e01
--- /dev/null
+++ b/MathPad/MPRangePath.m
@@ -0,0 +1,153 @@
+//
+//  MPRange.m
+//  MathPad
+//
+//  Created by Kim Wittenburg on 18.04.14.
+//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
+//
+
+#import "MPRangePath.h"
+
+@implementation MPRangePath
+
+#pragma mark Creation Methods
+
+- (instancetype)init
+{
+    return [self initWithLocation:[[NSIndexPath alloc] init]
+                           length:0];
+}
+
+- (instancetype)initWithLocation:(NSIndexPath *)location
+                          length:(NSUInteger)length
+{
+    self = [super init];
+    if (self) {
+        _location = location;
+        _length = length;
+    }
+    return self;
+}
+
+- (instancetype)initWithRange:(NSRange)aRange
+{
+    return [self initWithLocation:[[NSIndexPath alloc] initWithIndex:aRange.location]
+                           length:aRange.length];
+}
+
++ (instancetype)emptyRangePath
+{
+    return [[self alloc] init];
+}
+
++ (instancetype)rangePathWithLocation:(NSIndexPath *)location
+                           length:(NSUInteger)length
+{
+    return [[self alloc] initWithLocation:location
+                                      length:length];
+}
+
++ (instancetype)rangePathWithRange:(NSRange)aRange
+{
+    return [[self alloc] initWithRange:aRange];
+}
+
+#pragma mark Properties
+
+- (NSIndexPath *)maxRangePath
+{
+    NSUInteger lastIndex = [self.location indexAtPosition:self.location.length-1];
+    NSUInteger newLastIndex = lastIndex + self.length;
+    return [[self.location indexPathByRemovingLastIndex] indexPathByAddingIndex:newLastIndex];
+}
+
+- (NSRange)rangeAtLastIndex
+{
+    return NSMakeRange([self.location indexAtPosition:self.location.length-1], self.length);
+}
+
+#pragma mark Working with Ranges
+
+- (BOOL)containsRangePath:(MPRangePath *)aRangePath
+{
+    if (aRangePath.location.length < self.location.length) {
+        return NO;
+    }
+    // Compare indices (except the last one)
+    for (NSUInteger pos = 0; pos < self.location.length-1; pos++) {
+        NSUInteger selfIndex = [self.location indexAtPosition:pos];
+        NSUInteger otherIndex = [aRangePath.location indexAtPosition:pos];
+        if (selfIndex != otherIndex) {
+            return NO;
+        }
+    }
+    // Compare range at last index
+    NSUInteger selfIndex = [self.location indexAtPosition:self.location.length-1];
+    NSUInteger otherIndex = [aRangePath.location indexAtPosition:self.location.length-1];
+    if (aRangePath.location.length > self.location.length) {
+        return NSLocationInRange(otherIndex, self.rangeAtLastIndex);
+    } else {
+        return otherIndex >= selfIndex && NSMaxRange(aRangePath.rangeAtLastIndex) <= NSMaxRange(self.rangeAtLastIndex);
+    }
+}
+
+- (BOOL)containsLocation:(NSIndexPath *)location
+{
+    return [self containsRangePath:[[MPRangePath alloc] initWithLocation:location length:0]];
+}
+
+- (BOOL)isEqual:(id)object
+{
+    if (self == object) {
+        return YES;
+    }
+    if (object == nil) {
+        return NO;
+    }
+    if (![object isKindOfClass:[MPRangePath class]]) {
+        return NO;
+    }
+    return [self isEqualToRangePath:(MPRangePath *)object];
+}
+
+- (BOOL)isEqualToRangePath:(MPRangePath *)aRangePath
+{
+    return [self.location isEqual:aRangePath.location] && self.length == aRangePath.length;
+}
+
+#pragma mark - NSCopying
+
+- (id)copyWithZone:(NSZone *)zone
+{
+    MPRangePath *copy = [[MPRangePath allocWithZone:zone] initWithLocation:self.location.copy length:self.length];
+    return copy;
+}
+
+#pragma mark - NSCoding
+
+- (id)initWithCoder:(NSCoder *)aDecoder
+{
+    return [self initWithLocation:[aDecoder decodeObjectForKey:@"location"]
+                           length:[aDecoder decodeIntegerForKey:@"length"]];
+}
+
+- (void)encodeWithCoder:(NSCoder *)aCoder
+{
+    [aCoder encodeObject:self.location forKey:@"location"];
+    [aCoder encodeInteger:self.length forKey:@"length"];
+}
+
+@end
+
+@implementation MPExpression (MPRangeExtension)
+
+- (MPExpression *)subexpressionWithRangePath:(MPRangePath *)aRangePath
+{
+    MPExpression *targetExpression = [self symbolAtIndexPath:[aRangePath.location indexPathByRemovingLastIndex]];
+    if (![targetExpression isKindOfClass:[MPExpression class]]) {
+        return nil;
+    }
+    return [targetExpression subexpressionWithRange:aRangePath.rangeAtLastIndex];
+}
+
+@end