48 lines
1.0 KiB
Objective-C
48 lines
1.0 KiB
Objective-C
//
|
|
// MPParsedVariable.m
|
|
// MathPad
|
|
//
|
|
// Created by Kim Wittenburg on 13.09.14.
|
|
// Copyright (c) 2014 Kim Wittenburg. All rights reserved.
|
|
//
|
|
|
|
#import "MPParsedVariable.h"
|
|
#import "MPEvaluationContext.h"
|
|
|
|
@interface MPParsedVariable ()
|
|
@property (nonatomic) NSRange range;
|
|
@property (nonatomic, strong) NSString *variableName;
|
|
@end
|
|
|
|
@implementation MPParsedVariable
|
|
|
|
- (instancetype)initWithRange:(NSRange)range
|
|
inString:(NSString *)string
|
|
{
|
|
self = [super init];
|
|
if (self) {
|
|
_range = range;
|
|
if (range.location != NSNotFound) {
|
|
_variableName = [string substringWithRange:range];
|
|
}
|
|
}
|
|
return self;
|
|
}
|
|
|
|
- (BOOL)exists
|
|
{
|
|
return self.range.location != NSNotFound;
|
|
}
|
|
|
|
- (NSDecimalNumber *)evaluateWithError:(MPParseError *__autoreleasing *)error
|
|
{
|
|
NSDecimalNumber *value = [[MPEvaluationContext sharedContext] valueForVariableName:self.variableName];
|
|
if (!value) {
|
|
*error = MPParseError(self.range, @"Undefined Variable.");
|
|
return nil;
|
|
}
|
|
return value;
|
|
}
|
|
|
|
@end
|