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
151
152
153
154
155
156
157
158
159
160
161
162
163

//! Common string-like types and routines.

use std::fmt;
use std::ops;
use lex::Keyword;

fn is_unquotable(s: &[u8]) -> bool {
    fn is_first(c: u8) -> bool {
        match c { b'_' | b'a'...b'z' | b'A'...b'Z' => true, _ => false }
    }

    fn is_next(c: u8) -> bool {
        match c { b'_' | b'a'...b'z' | b'A'...b'Z' | b'0'...b'9' => true, _ => false }
    }

    !s.is_empty() && is_first(s[0])
                  && s[1..].iter().all(|&c| is_next(c))
                  && Keyword::from(s, true).is_none()
}

fn format_ascii_vec(f: &mut fmt::Formatter, s: &[u8]) -> fmt::Result {
    for &c in s {
        match c {
            b'\t' => write!(f, "\\t")?,
            b'\n' => write!(f, "\\n")?,
            b'\r' => write!(f, "\\r")?,
            b'"' | b'\'' | b'`' | b'\\' => write!(f, "\\{}", c as char)?,
            b'\x20'...b'\x7e' => write!(f, "{}", c as char)?,
            _ => write!(f, "\\x{:02x}", c)?,
        }
    }
    Ok(())
}

/// A name from the source code.
///
/// This may include non-identifier bytes if constructed from a quoted name in the meta block.
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Name(Box<[u8]>);

impl Name {
    /// Returns true if the name is not an ordinary identifier
    /// for all known versions of Lua and Kailua.
    pub fn quote_required(&self) -> bool { !is_unquotable(&self.0) }

    /// Extracts the owned slice.
    pub fn into_bytes(self) -> Box<[u8]> { self.0 }
}

impl From<Box<[u8]>> for Name {
    fn from(n: Box<[u8]>) -> Name { Name(n) }
}

impl From<Vec<u8>> for Name {
    fn from(n: Vec<u8>) -> Name { Name(n.into_boxed_slice()) }
}

impl ops::Deref for Name {
    type Target = [u8];
    fn deref(&self) -> &[u8] { &self.0[..] }
}

/// Same to the `Debug` implementation.
impl fmt::Display for Name {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        fmt::Debug::fmt(self, f)
    }
}

/// A name can be formatted in three ways:
///
/// * `{}` will always print backquotes. Suitable for error messages.
/// * `{:-}` won't print any backquotes.
/// * `{:+}` will print backquotes when required (see also `Name::quote_required`).
///
/// In any case, non-printable bytes are escaped as like `\r` or `\xab`;
/// any quotes (`'`, `"` or `` ` ``) are also escaped.
/// This makes switching quotes possible: `"{:-}"` will equal to the `Str` output.
impl fmt::Debug for Name {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        let quote = if f.sign_plus() { self.quote_required() } else { !f.sign_minus() };
        if quote { write!(f, "`")?; }
        format_ascii_vec(f, &self.0)?;
        if quote { write!(f, "`")?; }
        Ok(())
    }
}

/// A string (or sometimes a desugared name) from the source code.
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Str(Box<[u8]>);

impl Str {
    /// Returns true if the string is not an ordinary identifier
    /// for all known versions of Lua and Kailua.
    pub fn quote_required(&self) -> bool { !is_unquotable(&self.0) }

    /// Extracts the owned slice.
    pub fn into_bytes(self) -> Box<[u8]> { self.0 }
}

impl From<Box<[u8]>> for Str {
    fn from(s: Box<[u8]>) -> Str { Str(s) }
}

impl From<Vec<u8>> for Str {
    fn from(s: Vec<u8>) -> Str { Str(s.into_boxed_slice()) }
}

impl ops::Deref for Str {
    type Target = [u8];
    fn deref(&self) -> &[u8] { &self.0[..] }
}

impl fmt::Display for Str {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        fmt::Debug::fmt(self, f)
    }
}

/// A string can be formatted in three ways:
///
/// * `{}` will always print double quotes. Suitable for error messages.
/// * `{:-}` won't print any double quotes.
/// * `{:+}` will print double quotes when required (see also `Str::quote_required`).
///
/// In any case, non-printable bytes are escaped as like `\r` or `\xab`;
/// any quotes (`'`, `"` or `` ` ``) are also escaped.
/// This makes switching quotes possible: `` `{:-}` `` will equal to the `Name` output.
impl fmt::Debug for Str {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        let quote = if f.sign_plus() { self.quote_required() } else { !f.sign_minus() };
        if quote { write!(f, "\"")?; }
        format_ascii_vec(f, &self.0)?;
        if quote { write!(f, "\"")?; }
        Ok(())
    }
}

impl<'a> From<&'a [u8]> for Name {
    fn from(s: &'a [u8]) -> Name { Name(s.to_owned().into_boxed_slice()) }
}

impl<'a> From<&'a [u8]> for Str {
    fn from(s: &'a [u8]) -> Str { Str(s.to_owned().into_boxed_slice()) }
}

impl<'a> From<&'a Name> for Name {
    fn from(n: &'a Name) -> Name { n.clone() }
}

impl<'a> From<&'a Str> for Str {
    fn from(s: &'a Str) -> Str { s.clone() }
}

impl From<Str> for Name {
    fn from(Str(s): Str) -> Name { Name(s) }
}

impl From<Name> for Str {
    fn from(Name(n): Name) -> Str { Str(n) }
}