src/test/run-pass/regions-mock-tcx.rs

   1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11
  12 // Test a sample usage pattern for regions. Makes use of the
  13 // following features:
  14 //
  15 // - Multiple lifetime parameters
  16 // - Arenas
  17
  18 #![feature(rustc_private, libc, collections)]
  19
  20 extern crate arena;
  21 extern crate collections;
  22 extern crate libc;
  23
  24 use TypeStructure::{TypeInt, TypeFunction};
  25 use AstKind::{ExprInt, ExprVar, ExprLambda};
  26 use arena::TypedArena;
  27 use std::collections::HashMap;
  28 use std::mem;
  29
  30 type Type<'tcx> = &'tcx TypeStructure<'tcx>;
  31
  32 #[derive(Copy, Clone, Debug)]
  33 enum TypeStructure<'tcx> {
  34     TypeInt,
  35     TypeFunction(Type<'tcx>, Type<'tcx>),
  36 }
  37
  38 impl<'tcx> PartialEq for TypeStructure<'tcx> {
  39     fn eq(&self, other: &TypeStructure<'tcx>) -> bool {
  40         match (*self, *other) {
  41             (TypeInt, TypeInt) => true,
  42             (TypeFunction(s_a, s_b), TypeFunction(o_a, o_b)) => *s_a == *o_a && *s_b == *o_b,
  43             _ => false
  44         }
  45     }
  46 }
  47
  48 impl<'tcx> Eq for TypeStructure<'tcx> {}
  49
  50 type TyArena<'tcx> = TypedArena<TypeStructure<'tcx>>;
  51 type AstArena<'ast> = TypedArena<AstStructure<'ast>>;
  52
  53 struct TypeContext<'tcx, 'ast> {
  54     ty_arena: &'tcx TyArena<'tcx>,
  55     types: Vec<Type<'tcx>> ,
  56     type_table: HashMap<NodeId, Type<'tcx>>,
  57
  58     ast_arena: &'ast AstArena<'ast>,
  59     ast_counter: usize,
  60 }
  61
  62 impl<'tcx,'ast> TypeContext<'tcx, 'ast> {
  63     fn new(ty_arena: &'tcx TyArena<'tcx>, ast_arena: &'ast AstArena<'ast>)
  64            -> TypeContext<'tcx, 'ast> {
  65         TypeContext { ty_arena: ty_arena,
  66                       types: Vec::new(),
  67                       type_table: HashMap::new(),
  68
  69                       ast_arena: ast_arena,
  70                       ast_counter: 0 }
  71     }
  72
  73     fn add_type(&mut self, s: TypeStructure<'tcx>) -> Type<'tcx> {
  74         for &ty in &self.types {
  75             if *ty == s {
  76                 return ty;
  77             }
  78         }
  79
  80         let ty = self.ty_arena.alloc(s);
  81         self.types.push(ty);
  82         ty
  83     }
  84
  85     fn set_type(&mut self, id: NodeId, ty: Type<'tcx>) -> Type<'tcx> {
  86         self.type_table.insert(id, ty);
  87         ty
  88     }
  89
  90     fn ast(&mut self, a: AstKind<'ast>) -> Ast<'ast> {
  91         let id = self.ast_counter;
  92         self.ast_counter += 1;
  93         self.ast_arena.alloc(AstStructure { id: NodeId {id:id}, kind: a })
  94     }
  95 }
  96
  97 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
  98 struct NodeId {
  99     id: usize
 100 }
 101
 102 type Ast<'ast> = &'ast AstStructure<'ast>;
 103
 104 #[derive(Copy, Clone)]
 105 struct AstStructure<'ast> {
 106     id: NodeId,
 107     kind: AstKind<'ast>
 108 }
 109
 110 #[derive(Copy, Clone)]
 111 enum AstKind<'ast> {
 112     ExprInt,
 113     ExprVar(usize),
 114     ExprLambda(Ast<'ast>),
 115 }
 116
 117 fn compute_types<'tcx,'ast>(tcx: &mut TypeContext<'tcx,'ast>,
 118                             ast: Ast<'ast>) -> Type<'tcx>
 119 {
 120     match ast.kind {
 121         ExprInt | ExprVar(_) => {
 122             let ty = tcx.add_type(TypeInt);
 123             tcx.set_type(ast.id, ty)
 124         }
 125         ExprLambda(ast) => {
 126             let arg_ty = tcx.add_type(TypeInt);
 127             let body_ty = compute_types(tcx, ast);
 128             let lambda_ty = tcx.add_type(TypeFunction(arg_ty, body_ty));
 129             tcx.set_type(ast.id, lambda_ty)
 130         }
 131     }
 132 }
 133
 134 pub fn main() {
 135     let ty_arena = TypedArena::new();
 136     let ast_arena = TypedArena::new();
 137     let mut tcx = TypeContext::new(&ty_arena, &ast_arena);
 138     let ast = tcx.ast(ExprInt);
 139     let ty = compute_types(&mut tcx, ast);
 140     assert_eq!(*ty, TypeInt);
 141 }