1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55

use {RString, Object, EncodingSupport};
use types::{c_char, c_int, InternalValue};
use rubysys::string::{rstring_ptr, rstring_end};
use binding::{string, encoding};

/// `CodepointIterator`
#[derive(Debug)]
pub struct CodepointIterator {
    rstring: RString,
    ptr: *const c_char,
}

impl CodepointIterator {
    /// Create new codepoint iterator
    ///
    /// ```
    /// use rutie::{RString, VM, CodepointIterator};
    /// # VM::init();
    ///
    /// let string = RString::new_utf8("aeiou");
    /// let ci = CodepointIterator::new(&string);
    ///
    /// let result: Vec<usize> = ci.into_iter().collect();
    ///
    /// assert_eq!(vec![97, 101, 105, 111, 117], result);
    /// ```
    pub fn new(rstring: &RString) -> Self {
        let fstring = string::new_frozen(rstring.value());

        CodepointIterator {
            rstring: RString::from(fstring),
            ptr: unsafe { rstring_ptr(fstring) },
        }
    }
}

impl Iterator for CodepointIterator {
    type Item = usize;

    fn next(&mut self) -> Option<Self::Item> {
        let mut n: c_int = 0;

        let ptr = self.ptr;
        let end = unsafe { rstring_end(self.rstring.value()) };
        let enc = self.rstring.encoding();

        if ptr < end {
            let result = Some(encoding::next_codepoint(ptr, end, &mut n, enc.value()));
            self.ptr = unsafe { ptr.add(n as usize) };
            result
        } else {
            None
        }
    }
}