1 files changed, 71 insertions, 0 deletions
diff --git a/woip/app/ReadStream.m b/woip/app/ReadStream.m
new file mode 100644
index 0000000..a02cfb2
--- /dev/null
+++ b/woip/app/ReadStream.m
@@ -0,0 +1,71 @@
+#import "ReadStream.h"
+
+@implementation ReadStream
+
+-(ReadStream *) initWithString: (NSString *) s {
+  [self init];
+  str = s;
+  pos = 0;
+  return self;
+}
+
+-(unichar) safeCharAtIndex: (int) i {
+  return [self isAtEnd] ? 0 : [str characterAtIndex: i];
+}
+
+-(unichar) peekBack {
+  return [self safeCharAtIndex: pos - 1];
+}
+
+-(unichar) peek {
+  return [self safeCharAtIndex: pos];
+}
+
+-(unichar) peekTwo {
+  return [self safeCharAtIndex: pos + 1];
+}
+
+-(unichar) read {
+  unichar c = [self safeCharAtIndex: pos];
+  pos++;
+  return c;
+}
+
+-(BOOL) isAtEnd {
+  return pos == [str length];
+}
+
+-(unichar) expect: (unichar) c {
+  unichar r;
+  if((r = [self read]) != c) NSLog(@"WARNING: expected %c at position %d, found %c", c, pos - 1, r);
+  return r;
+}
+
+-(NSString *) readUpto: (unichar) c {
+  int found = pos;
+  
+  while(found != [str length] && [self safeCharAtIndex: found++] != c);
+  //if(found == [str length]) return NULL; // not found
+  
+  found--;
+  NSString *s = [str substringWithRange: NSMakeRange(pos, found - pos)];
+  pos = found;
+  
+  return s;
+}
+
+/*-(NSString *) readUptoString: (NSString *) s {
+  NSRange range = [str rangeOfString: s options: 0 range: NSMakeRange(pos, [str length] - pos)];
+  NSString *text;
+
+  if(range.location != NSNotFound) {
+    text = [str substringToIndex: range.location];
+    pos = range.location;
+  } else {
+    text = [str substringFromIndex: pos];
+  }
+
+  return text;
+}*/
+
+@end