Question

I am trying to make a simple markup language, and I need my Cocoa app to be able to read it. I would prefer to have that code written in Objective-c, but I am happy to use any other language.

Here is my current problem. I am using this code:

for (int character = 1; character < ([script length] - 1); character ++) {
    NSLog(@"%@", [[script substringToIndex:character] substringFromIndex:([[script substringToIndex:character] length] - 2)]);

Unfortunately, if I pass the string [button] through it, it shows this in the debug console:

[
[b
[bu
[but
[butt
[__NSCFConstantString substringWithRange:]: Range or index out of bounds

I can sort out the error message, but I need to know how to read the script and recognize certain tags like [button]. Can anybody give me a link to something useful on this subject?

Answer 1

Just to give you examples:

NSString *str = @"[Button]";
NSUInteger i, len = [str length];

for (i = 1; i <= len; ++i)
    NSLog(@"%@", [str substringToIndex:i]);

for (i = 0; i < len; ++i)
    NSLog(@"%c", [str characterAtIndex:i]);

Output:

[
[B
[Bu
[But
[Butt
[Butto
[Button
[Button]
[
B
u
t
t
o
n
]

And a more interesting case:

for (i = 0; i < len; ++i)
    NSLog([NSString stringWithFormat:@"%%%dc", i+1],
          [str characterAtIndex:i]);

Which produces:

[
 B
  u
   t
    t
     o
      n
       ]