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
|
// Copyright 2012-2016 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use syntax::parse::token::InternedString;
use syntax::ast;
use std::rc::Rc;
use hir::def_id::DefId;
use std::hash;
use std::mem::transmute;
use rustc_const_math::*;
use self::ConstVal::*;
#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
pub enum ConstVal {
Float(f64),
Integral(ConstInt),
Str(InternedString),
ByteStr(Rc<Vec<u8>>),
Bool(bool),
Struct(ast::NodeId),
Tuple(ast::NodeId),
Function(DefId),
Array(ast::NodeId, u64),
Repeat(ast::NodeId, u64),
Char(char),
/// A value that only occurs in case `eval_const_expr` reported an error. You should never
/// handle this case. Its sole purpose is to allow more errors to be reported instead of
/// causing a fatal error.
Dummy,
}
impl hash::Hash for ConstVal {
fn hash<H: hash::Hasher>(&self, state: &mut H) {
match *self {
Float(a) => unsafe { transmute::<_,u64>(a) }.hash(state),
Integral(a) => a.hash(state),
Str(ref a) => a.hash(state),
ByteStr(ref a) => a.hash(state),
Bool(a) => a.hash(state),
Struct(a) => a.hash(state),
Tuple(a) => a.hash(state),
Function(a) => a.hash(state),
Array(a, n) => { a.hash(state); n.hash(state) },
Repeat(a, n) => { a.hash(state); n.hash(state) },
Char(c) => c.hash(state),
Dummy => ().hash(state),
}
}
}
/// Note that equality for `ConstVal` means that the it is the same
/// constant, not that the rust values are equal. In particular, `NaN
/// == NaN` (at least if it's the same NaN; distinct encodings for NaN
/// are considering unequal).
impl PartialEq for ConstVal {
fn eq(&self, other: &ConstVal) -> bool {
match (self, other) {
(&Float(a), &Float(b)) => unsafe{transmute::<_,u64>(a) == transmute::<_,u64>(b)},
(&Integral(a), &Integral(b)) => a == b,
(&Str(ref a), &Str(ref b)) => a == b,
(&ByteStr(ref a), &ByteStr(ref b)) => a == b,
(&Bool(a), &Bool(b)) => a == b,
(&Struct(a), &Struct(b)) => a == b,
(&Tuple(a), &Tuple(b)) => a == b,
(&Function(a), &Function(b)) => a == b,
(&Array(a, an), &Array(b, bn)) => (a == b) && (an == bn),
(&Repeat(a, an), &Repeat(b, bn)) => (a == b) && (an == bn),
(&Char(a), &Char(b)) => a == b,
(&Dummy, &Dummy) => true, // FIXME: should this be false?
_ => false,
}
}
}
impl Eq for ConstVal { }
impl ConstVal {
pub fn description(&self) -> &'static str {
match *self {
Float(_) => "float",
Integral(i) => i.description(),
Str(_) => "string literal",
ByteStr(_) => "byte string literal",
Bool(_) => "boolean",
Struct(_) => "struct",
Tuple(_) => "tuple",
Function(_) => "function definition",
Array(..) => "array",
Repeat(..) => "repeat",
Char(..) => "char",
Dummy => "dummy value",
}
}
}
|
