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
|
// run-pass
#![allow(dead_code)]
#![allow(unused_imports)]
// Test a sample usage pattern for regions. Makes use of the
// following features:
//
// - Multiple lifetime parameters
// - Arenas
#![feature(rustc_private, libc)]
extern crate rustc_arena;
extern crate libc;
// Necessary to pull in object code as the rest of the rustc crates are shipped only as rmeta
// files.
#[allow(unused_extern_crates)]
extern crate rustc_driver;
use TypeStructure::{TypeInt, TypeFunction};
use AstKind::{ExprInt, ExprVar, ExprLambda};
use rustc_arena::TypedArena;
use std::collections::HashMap;
use std::mem;
type Type<'tcx> = &'tcx TypeStructure<'tcx>;
#[derive(Copy, Clone, Debug)]
enum TypeStructure<'tcx> {
TypeInt,
TypeFunction(Type<'tcx>, Type<'tcx>),
}
impl<'tcx> PartialEq for TypeStructure<'tcx> {
fn eq(&self, other: &TypeStructure<'tcx>) -> bool {
match (*self, *other) {
(TypeInt, TypeInt) => true,
(TypeFunction(s_a, s_b), TypeFunction(o_a, o_b)) => *s_a == *o_a && *s_b == *o_b,
_ => false
}
}
}
impl<'tcx> Eq for TypeStructure<'tcx> {}
type TyArena<'tcx> = TypedArena<TypeStructure<'tcx>>;
type AstArena<'ast> = TypedArena<AstStructure<'ast>>;
struct TypeContext<'tcx, 'ast> {
ty_arena: &'tcx TyArena<'tcx>,
types: Vec<Type<'tcx>> ,
type_table: HashMap<NodeId, Type<'tcx>>,
ast_arena: &'ast AstArena<'ast>,
ast_counter: usize,
}
impl<'tcx,'ast> TypeContext<'tcx, 'ast> {
fn new(ty_arena: &'tcx TyArena<'tcx>, ast_arena: &'ast AstArena<'ast>)
-> TypeContext<'tcx, 'ast> {
TypeContext { ty_arena: ty_arena,
types: Vec::new(),
type_table: HashMap::new(),
ast_arena: ast_arena,
ast_counter: 0 }
}
fn add_type(&mut self, s: TypeStructure<'tcx>) -> Type<'tcx> {
for &ty in &self.types {
if *ty == s {
return ty;
}
}
let ty = self.ty_arena.alloc(s);
self.types.push(ty);
ty
}
fn set_type(&mut self, id: NodeId, ty: Type<'tcx>) -> Type<'tcx> {
self.type_table.insert(id, ty);
ty
}
fn ast(&mut self, a: AstKind<'ast>) -> Ast<'ast> {
let id = self.ast_counter;
self.ast_counter += 1;
self.ast_arena.alloc(AstStructure { id: NodeId {id:id}, kind: a })
}
}
#[derive(Copy, Clone, PartialEq, Eq, Hash)]
struct NodeId {
id: usize
}
type Ast<'ast> = &'ast AstStructure<'ast>;
#[derive(Copy, Clone)]
struct AstStructure<'ast> {
id: NodeId,
kind: AstKind<'ast>
}
#[derive(Copy, Clone)]
enum AstKind<'ast> {
ExprInt,
ExprVar(usize),
ExprLambda(Ast<'ast>),
}
fn compute_types<'tcx,'ast>(tcx: &mut TypeContext<'tcx,'ast>,
ast: Ast<'ast>) -> Type<'tcx>
{
match ast.kind {
ExprInt | ExprVar(_) => {
let ty = tcx.add_type(TypeInt);
tcx.set_type(ast.id, ty)
}
ExprLambda(ast) => {
let arg_ty = tcx.add_type(TypeInt);
let body_ty = compute_types(tcx, ast);
let lambda_ty = tcx.add_type(TypeFunction(arg_ty, body_ty));
tcx.set_type(ast.id, lambda_ty)
}
}
}
pub fn main() {
let ty_arena = TypedArena::default();
let ast_arena = TypedArena::default();
let mut tcx = TypeContext::new(&ty_arena, &ast_arena);
let ast = tcx.ast(ExprInt);
let ty = compute_types(&mut tcx, ast);
assert_eq!(*ty, TypeInt);
}
|
