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
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130

use super::*;

/// Wrapper for creating CHARSXP objects.
/// These are used only as the contents of a character
/// vector.
///
/// ```
/// use extendr_api::prelude::*;
/// test! {
///     let chr = r!(Rstr::from_string("xyz"));
///     assert_eq!(chr.as_char().unwrap().as_str(), "xyz");
/// }
/// ```
///
#[derive(Clone)]
pub struct Rstr {
    pub(crate) robj: Robj,
}

pub(crate) unsafe fn sexp_to_str(sexp: SEXP) -> &'static str {
    if sexp == R_NaString {
        <&str>::na()
    } else {
        std::mem::transmute(to_str(R_CHAR(sexp) as *const u8))
    }
}

impl Rstr {
    /// Make a character object from a string.
    pub fn from_string(val: &str) -> Self {
        Rstr {
            robj: Robj::from_sexp(str_to_character(val)),
        }
    }

    /// Get the string from a character object.
    /// If the string is NA, then the special na_str() is returned.
    pub fn as_str(&self) -> &str {
        unsafe { sexp_to_str(self.robj.get()) }
    }
}

impl AsRef<str> for Rstr {
    /// Treat a Rstr as a string slice.
    fn as_ref(&self) -> &str {
        self.as_str()
    }
}

impl From<String> for Rstr {
    /// Convert a String to a Rstr.
    fn from(s: String) -> Self {
        Rstr::from_string(&s)
    }
}

impl From<&str> for Rstr {
    /// Convert a string slice to a Rstr.
    fn from(s: &str) -> Self {
        Rstr::from_string(s)
    }
}

impl From<Option<String>> for Rstr {
    fn from(value: Option<String>) -> Self {
        if let Some(string) = value {
            Self::from(string)
        } else {
            Self { robj: na_string() }
        }
    }
}

impl Deref for Rstr {
    type Target = str;

    /// Treat `Rstr` like `&str`.
    fn deref(&self) -> &Self::Target {
        self.as_str()
    }
}

impl<T> PartialEq<T> for Rstr
where
    T: AsRef<str>,
{
    /// Compare a `Rstr` with a `Rstr`.
    fn eq(&self, other: &T) -> bool {
        self.as_str() == other.as_ref()
    }
}

impl PartialEq<str> for Rstr {
    /// Compare a `Rstr` with a string slice.
    fn eq(&self, other: &str) -> bool {
        self.as_str() == other
    }
}

impl std::fmt::Debug for Rstr {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        if self.is_na() {
            write!(f, "NA_CHARACTER")
        } else {
            let s = self.as_str();
            write!(f, "{:?}", s)
        }
    }
}

impl std::fmt::Display for Rstr {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let s = self.as_str();
        write!(f, "{}", s)
    }
}

impl CanBeNA for Rstr {
    fn is_na(&self) -> bool {
        unsafe { self.robj.get() == R_NaString }
    }

    fn na() -> Self {
        unsafe {
            Self {
                robj: Robj::from_sexp(R_NaString),
            }
        }
    }
}