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pEpObjCAdapter/pEpObjCAdapter/PEPCSVScanner.m

82 lines
1.9 KiB
Objective-C

//
// PEPCSVScanner.m
// pEpiOSAdapter
//
// Created by Dirk Zimmermann on 03.05.17.
// Copyright © 2017 p≡p. All rights reserved.
//
#import "PEPCSVScanner.h"
static unichar s_quoteChar = '"';
@interface PEPCSVScanner ()
@property (nonatomic) NSInteger position;
@property (nonatomic) NSInteger len;
@end;
@implementation PEPCSVScanner
- (instancetype _Nonnull )initWithString:(NSString * _Nonnull)string
{
if (self = [super init]) {
_string = string;
_len = [string length];
}
return self;
}
- (NSString * _Nullable)nextString
{
NSInteger startPos = NSNotFound;
for (NSInteger thePos = self.position; thePos < self.len; thePos++) {
if ([self startingQuoteAt:thePos]) {
startPos = thePos + 1;
for (NSInteger endPos = startPos; endPos < self.len; endPos++) {
if ([self endingQuoteAt:endPos]) {
self.position = endPos + 1;
return [self.string substringWithRange:NSMakeRange(startPos, endPos - startPos)];
}
}
}
}
return nil;
}
/**
@return YES if the given position points to a starting quote.
*/
- (BOOL)startingQuoteAt:(NSInteger)pos
{
// The last char can never be a starting quote
if (pos >= self.len - 1) {
return NO;
}
unichar ch1 = [self.string characterAtIndex:pos];
unichar ch2 = [self.string characterAtIndex:pos + 1];
if (ch1 == s_quoteChar && ch2 != s_quoteChar) {
return YES;
}
return NO;
}
/**
@return YES if the given position points to an ending quote.
*/
- (BOOL)endingQuoteAt:(NSInteger)pos
{
unichar ch1 = [self.string characterAtIndex:pos];
if (ch1 == s_quoteChar) {
if (pos == self.len - 1) {
return YES;
}
unichar ch2 = [self.string characterAtIndex:pos + 1];
return ch2 != s_quoteChar;
}
return NO;
}
@end