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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
use std::borrow::Cow;
use std::string::String as StdString;
use std::{slice, str};
#[cfg(feature = "serialize")]
use {
serde::ser::{Serialize, Serializer},
std::result::Result as StdResult,
};
use crate::error::{Error, Result};
use crate::ffi;
use crate::types::LuaRef;
use crate::util::{assert_stack, StackGuard};
/// Handle to an internal Lua string.
///
/// Unlike Rust strings, Lua strings may not be valid UTF-8.
#[derive(Clone, Debug)]
pub struct String<'lua>(pub(crate) LuaRef<'lua>);
impl<'lua> String<'lua> {
/// Get a `&str` slice if the Lua string is valid UTF-8.
///
/// # Examples
///
/// ```
/// # use mlua::{Lua, Result, String};
/// # fn main() -> Result<()> {
/// # let lua = Lua::new();
/// let globals = lua.globals();
///
/// let version: String = globals.get("_VERSION")?;
/// assert!(version.to_str()?.contains("Lua"));
///
/// let non_utf8: String = lua.load(r#" "test\255" "#).eval()?;
/// assert!(non_utf8.to_str().is_err());
/// # Ok(())
/// # }
/// ```
pub fn to_str(&self) -> Result<&str> {
str::from_utf8(self.as_bytes()).map_err(|e| Error::FromLuaConversionError {
from: "string",
to: "&str",
message: Some(e.to_string()),
})
}
/// Converts this string to a [`Cow<str>`].
///
/// Any non-Unicode sequences are replaced with [`U+FFFD REPLACEMENT CHARACTER`][U+FFFD].
///
/// [U+FFFD]: std::char::REPLACEMENT_CHARACTER
///
/// # Examples
///
/// ```
/// # use mlua::{Lua, Result};
/// # fn main() -> Result<()> {
/// let lua = Lua::new();
///
/// let s = lua.create_string(b"test\xff")?;
/// assert_eq!(s.to_string_lossy(), "test\u{fffd}");
/// # Ok(())
/// # }
/// ```
pub fn to_string_lossy(&self) -> Cow<'_, str> {
StdString::from_utf8_lossy(self.as_bytes())
}
/// Get the bytes that make up this string.
///
/// The returned slice will not contain the terminating nul byte, but will contain any nul
/// bytes embedded into the Lua string.
///
/// # Examples
///
/// ```
/// # use mlua::{Lua, Result, String};
/// # fn main() -> Result<()> {
/// # let lua = Lua::new();
/// let non_utf8: String = lua.load(r#" "test\255" "#).eval()?;
/// assert!(non_utf8.to_str().is_err()); // oh no :(
/// assert_eq!(non_utf8.as_bytes(), &b"test\xff"[..]);
/// # Ok(())
/// # }
/// ```
pub fn as_bytes(&self) -> &[u8] {
let nulled = self.as_bytes_with_nul();
&nulled[..nulled.len() - 1]
}
/// Get the bytes that make up this string, including the trailing nul byte.
pub fn as_bytes_with_nul(&self) -> &[u8] {
let lua = self.0.lua;
unsafe {
let _sg = StackGuard::new(lua.state);
assert_stack(lua.state, 1);
lua.push_ref(&self.0);
mlua_debug_assert!(
ffi::lua_type(lua.state, -1) == ffi::LUA_TSTRING,
"string ref is not string type"
);
let mut size = 0;
// This will not trigger a 'm' error, because the reference is guaranteed to be of
// string type
let data = ffi::lua_tolstring(lua.state, -1, &mut size);
slice::from_raw_parts(data as *const u8, size + 1)
}
}
}
impl<'lua> AsRef<[u8]> for String<'lua> {
fn as_ref(&self) -> &[u8] {
self.as_bytes()
}
}
// Lua strings are basically &[u8] slices, so implement PartialEq for anything resembling that.
//
// This makes our `String` comparable with `Vec<u8>`, `[u8]`, `&str`, `String` and `mlua::String`
// itself.
//
// The only downside is that this disallows a comparison with `Cow<str>`, as that only implements
// `AsRef<str>`, which collides with this impl. Requiring `AsRef<str>` would fix that, but limit us
// in other ways.
impl<'lua, T> PartialEq<T> for String<'lua>
where
T: AsRef<[u8]>,
{
fn eq(&self, other: &T) -> bool {
self.as_bytes() == other.as_ref()
}
}
#[cfg(feature = "serialize")]
impl<'lua> Serialize for String<'lua> {
fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error>
where
S: Serializer,
{
match self.to_str() {
Ok(s) => serializer.serialize_str(s),
Err(_) => serializer.serialize_bytes(self.as_bytes()),
}
}
}
|