Mercurial > python-compiler.rs

comparison src/ast_type.rs @ 0:211b0df72e64

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Hello world!
author Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
date Sun, 29 May 2016 19:15:02 +0100
parents
children 5fc7c2790d8c
comparison
equal deleted inserted replaced
-1:000000000000 0:211b0df72e64
1 use python_ast::{Module, Statement, Expr, BinOp};
2
3 use std::collections::HashMap;
4
5 #[derive(Clone, Debug, PartialEq, Eq)]
6 enum Type {
7 Top(usize),
8 Unit,
9 Bool,
10 Int,
11 Str,
12 Function(Vec<Type>, Vec<Type>),
13 Bottom
14 }
15
16 struct TypeVariable {
17 id: usize,
18 instance: Box<TypeVariable>,
19 }
20
21 trait Visitor<T> {
22 fn visit_module(&mut self, module: Module) -> T;
23 fn visit_statement(&mut self, statement: Statement) -> T;
24 fn visit_expr(&mut self, expr: Expr) -> T;
25 }
26
27 struct Typing {
28 environment: Vec<HashMap<String, Type>>,
29 next_id: usize,
30 }
31
32 impl Visitor<Type> for Typing {
33 fn visit_module(&mut self, module: Module) -> Type {
34 println!("{:?}", self.environment);
35 for statement in module.statements {
36 self.visit_statement(statement);
37 }
38 println!("{:?}", self.environment);
39 Type::Bottom
40 }
41
42 fn visit_statement(&mut self, statement: Statement) -> Type {
43 match statement {
44 Statement::FunctionDef(Expr::Name(name), arguments, body) => {
45 let mut env = self.environment.pop().unwrap();
46 self.environment.push(env.clone());
47
48 let nb_args = arguments.len();
49 for expr in arguments {
50 let type_ = self.visit_expr(expr.clone());
51 let name = match expr {
52 Expr::Name(name) => name,
53 _ => panic!()
54 };
55 env.insert(name.clone(), type_.clone());
56 }
57 self.environment.push(env);
58
59 for statement in body {
60 self.visit_statement(statement);
61 }
62 self.environment.pop();
63
64 let mut types = Vec::with_capacity(nb_args);
65 for _ in 0..nb_args {
66 self.next_id += 1;
67 types.push(Type::Top(self.next_id));
68 }
69 Type::Bottom
70 },
71 Statement::FunctionDef(_, _, _) => {
72 println!("Statement:FunctionDef Error");
73 panic!()
74 },
75 Statement::Global(_) => {
76 Type::Bottom
77 },
78 Statement::If(test, body, orelse) => {
79 self.visit_expr(test);
80 for statement in body {
81 self.visit_statement(statement);
82 }
83 for statement in orelse {
84 self.visit_statement(statement);
85 }
86 Type::Bottom
87 },
88 Statement::Assign(targets, value) => {
89 let type_ = self.visit_expr(value);
90 if targets.len() != 1 {
91 panic!();
92 }
93 println!("{:?}", self.environment.clone());
94 let mut env = self.environment.pop().unwrap();
95 for target in targets {
96 let name = match target {
97 Expr::Name(name) => name,
98 _ => panic!()
99 };
100 println!("{} => {:?}", name, type_);
101 env.insert(name, type_.clone());
102 }
103 self.environment.push(env);
104 println!("{:?}", self.environment.clone());
105 Type::Bottom
106 },
107 Statement::Return(expr) => {
108 self.visit_expr(expr)
109 },
110 Statement::ImportFrom(module, names) => {
111 for alias in names {
112 self.visit_expr(alias);
113 }
114 Type::Bottom
115 },
116 Statement::Expr(expr) => {
117 self.visit_expr(expr)
118 },
119 Statement::Error => {
120 println!("Statement::Error");
121 panic!()
122 },
123 }
124 }
125
126 fn visit_expr(&mut self, expr: Expr) -> Type {
127 let expr_str = format!("{:?}", expr);
128 let type_ = match expr {
129 Expr::BinOp(left, op, right) => {
130 let type_left = self.visit_expr(*left);
131 let type_right = self.visit_expr(*right);
132
133 if op == BinOp::BinMult && type_left == Type::Str && type_right == Type::Int {
134 return Type::Str;
135 }
136
137 if type_left != type_right {
138 return Type::Bottom;
139 }
140 if op == BinOp::BinAdd || op == BinOp::BinMult {
141 if type_left == Type::Int {
142 Type::Int
143 } else if type_left == Type::Str {
144 Type::Str
145 } else {
146 Type::Bottom
147 }
148 } else if op == BinOp::BinEq || op == BinOp::BinLt {
149 Type::Bool
150 } else {
151 Type::Bottom
152 }
153 },
154 Expr::Compare(_, _, _) => Type::Bool,
155 Expr::Call(func, args) => {
156 let func = *func;
157 let func = match func {
158 Expr::Name(arg) => arg,
159 _ => panic!()
160 };
161 let mut types = vec!();
162 for expr in args {
163 let type_ = self.visit_expr(expr);
164 types.push(type_);
165 }
166 println!("types: {:?}", types);
167 let env = match self.environment.pop() {
168 Some(env) => env,
169 None => return Type::Bottom
170 };
171 if env.contains_key(&func) {
172 let value = env.get(&func).unwrap().clone();
173 self.environment.push(env);
174 value
175 } else {
176 self.environment.push(env);
177 Type::Bottom
178 }
179 },
180 Expr::Alias(_, _) => Type::Bottom,
181 Expr::Name(id) => {
182 let env = match self.environment.pop() {
183 Some(env) => env,
184 None => return Type::Bottom
185 };
186 if env.contains_key(&id) {
187 let value = env.get(&id).unwrap().clone();
188 self.environment.push(env);
189 value
190 } else {
191 self.environment.push(env);
192 self.next_id += 1;
193 Type::Top(self.next_id)
194 }
195 },
196 Expr::NameConstant(value) => {
197 if value == "True" || value == "False" {
198 Type::Bool
199 } else if value == "None" {
200 Type::Unit
201 } else {
202 Type::Bottom
203 }
204 },
205 Expr::Str(_) => Type::Str,
206 Expr::Num(_) => Type::Int,
207 Expr::Error => {
208 println!("Expr::Error");
209 panic!()
210 }
211 };
212 println!("{} => {:?}", expr_str, type_);
213 type_
214 }
215 }
216
217 #[allow(dead_code)]
218 pub fn type_ast(ast: Module) {
219 let mut environment = HashMap::new();
220 environment.insert("int".to_string(), Type::Int);
221 environment.insert("__name__".to_string(), Type::Str);
222 environment.insert("print".to_string(), Type::Unit);
223 let mut typing = Typing{environment: vec!(environment), next_id: 0};
224 typing.visit_module(ast);
225 }