Switch to a type representation supporting parametric polymorphism

Author: antoyo

tiger/src/ast.rs

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019 Boucher, Antoni <bouanto@zoho.com>
+ * Copyright (c) 2017-2024 Boucher, Antoni <bouanto@zoho.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -147,6 +147,7 @@ pub struct FuncDeclaration {
     pub params: Vec<FieldWithPos>,
     pub pure: bool,
     pub result: Option<SymbolWithPos>,
+    pub ty_vars: TypeVars,
 }
 
 pub type FuncDeclarationWithPos = WithPos<FuncDeclaration>;
@@ -178,7 +179,24 @@ pub struct RecordField {
 pub type RecordFieldWithPos = WithPos<RecordField>;
 
 #[derive(Clone, Debug, PartialEq)]
-pub enum Ty {
+pub struct Ty {
+    pub typ: InnerTypeWithPos,
+    pub args: TypeArgsWithPos,
+}
+
+impl Ty {
+    pub fn new(typ: InnerTypeWithPos) -> Self {
+        Self {
+            args: WithPos::new(TypeArgs {
+                types: vec![],
+            }, typ.pos),
+            typ,
+        }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub enum InnerType {
     Array {
         ident: SymbolWithPos,
     },
@@ -195,12 +213,35 @@ pub enum Ty {
     Unit,
 }
 
+pub type InnerTypeWithPos = WithPos<InnerType>;
+
 #[derive(Clone, Debug, PartialEq)]
 pub struct TypeDec {
     pub name: SymbolWithPos,
     pub ty: TyWithPos,
+    pub ty_vars: TypeVars,
 }
 
+#[derive(Clone, Debug, PartialEq)]
+pub struct TypeVars {
+    pub idents: Vec<SymbolWithPos>,
+}
+
+impl TypeVars {
+    pub fn new() -> Self {
+        Self {
+            idents: vec![],
+        }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct TypeArgs {
+    pub types: Vec<TyWithPos>,
+}
+
+pub type TypeArgsWithPos = WithPos<TypeArgs>;
+
 pub type TypeDecWithPos = WithPos<TypeDec>;
 
 pub type TyWithPos = WithPos<Ty>;

tiger/src/env.rs

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019 Boucher, Antoni <bouanto@zoho.com>
+ * Copyright (c) 2017-2024 Boucher, Antoni <bouanto@zoho.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -26,10 +26,11 @@ use escape::{DepthEscape, EscapeEnv};
 use frame::Frame;
 use gen;
 use gen::{Access, Level};
-use position::WithPos;
 use symbol::{Strings, Symbol, Symbols};
 use temp::Label;
-use types::{Type, Unique};
+use types::Type;
+
+use crate::types::{TyVar, TypeConstructor};
 
 #[derive(Clone, Debug)]
 pub enum Entry<F: Clone + Frame> {
@@ -64,24 +65,23 @@ impl<F: Clone + Frame> Env<F> {
     pub fn new(strings: &Rc<Strings>, escape_env: EscapeEnv) -> Self {
         let mut type_env = Symbols::new(Rc::clone(strings));
         let int_symbol = type_env.symbol("int");
-        type_env.enter(int_symbol, Type::Int);
+        type_env.enter(int_symbol, Type::new_int());
         let string_symbol = type_env.symbol("string");
-        type_env.enter(string_symbol, Type::String);
+        type_env.enter(string_symbol, Type::new_string());
 
         let object_symbol = type_env.symbol("Object");
         let answer_symbol = type_env.symbol("answer");
         let cont_symbol = type_env.symbol("cont");
         let string_consumer_symbol = type_env.symbol("stringConsumer");
 
-        let object_class = Type::Class {
+        let object_class = Type::App(TypeConstructor::new_unique(TypeConstructor::Class {
             data_layout: String::new(),
             fields: vec![],
             methods: vec![],
             name: object_symbol,
             parent_class: None,
-            unique: Unique::new(),
             vtable_name: Label::with_name("__vtable_Object"),
-        };
+        }), vec![]);
 
         let var_env = Symbols::new(Rc::clone(strings));
         let mut env = Self {
@@ -96,15 +96,9 @@ impl<F: Clone + Frame> Env<F> {
 
         env.enter_type(object_symbol, object_class);
 
-        env.enter_type(answer_symbol, Type::Answer);
-        env.enter_type(cont_symbol, Type::Function {
-            parameters: vec![],
-            return_type: Box::new(Type::Answer),
-        });
-        env.enter_type(string_consumer_symbol, Type::Function {
-            parameters: vec![Type::String],
-            return_type: Box::new(Type::Answer),
-        });
+        env.enter_type(answer_symbol, Type::new_answer());
+        env.enter_type(cont_symbol, Type::App(TypeConstructor::Arrow, vec![Type::new_answer()]));
+        env.enter_type(string_consumer_symbol, Type::App(TypeConstructor::Arrow, vec![Type::new_string(), Type::new_answer()]));
 
         env
     }
@@ -180,27 +174,28 @@ impl<F: Clone + Frame> Env<F> {
 
     pub fn external_functions(&mut self) -> BTreeMap<&'static str, (Vec<Type>, Type, bool)> {
         let mut functions = BTreeMap::new();
-        functions.insert("print", (vec![Type::String], Type::Unit, false));
-        functions.insert("printi", (vec![Type::Int], Type::Unit, false));
-        functions.insert("flush", (vec![], Type::Unit, false));
-        functions.insert("getchar", (vec![], Type::String, false));
-        functions.insert("ord", (vec![Type::String], Type::Int, true));
-        functions.insert("chr", (vec![Type::Int], Type::String, true));
-        functions.insert("size", (vec![Type::String], Type::Int, true));
-        functions.insert("substring", (vec![Type::String, Type::Int, Type::Int], Type::String, true));
-        functions.insert("concat", (vec![Type::String, Type::String], Type::String, true));
-        functions.insert("not", (vec![Type::Int], Type::Int, true));
-        functions.insert("stringEqual", (vec![Type::String, Type::String], Type::Int, true));
-
-        let cont = Type::Name(WithPos::dummy(self.type_env.symbol("cont")), None);
-        functions.insert("printP", (vec![Type::String, cont.clone()], Type::Answer, true));
-        functions.insert("flushP", (vec![cont], Type::Answer, true));
-        functions.insert("getcharP", (vec![Type::Name(WithPos::dummy(self.type_env.symbol("stringConsumer")), None)], Type::Answer, true));
-        functions.insert("exit", (vec![], Type::Answer, true));
-
-        functions.insert("allocClass", (vec![Type::Int], Type::Int, true));
-        functions.insert("allocRecord", (vec![Type::Int], Type::Int, true));
-        functions.insert("initArray", (vec![Type::Int, Type::Int], Type::Int, true));
+        functions.insert("print", (vec![Type::new_string()], Type::new_unit(), false));
+        functions.insert("printi", (vec![Type::new_int()], Type::new_unit(), false));
+        functions.insert("flush", (vec![], Type::new_unit(), false));
+        functions.insert("getchar", (vec![], Type::new_string(), false));
+        functions.insert("ord", (vec![Type::new_string()], Type::new_int(), true));
+        functions.insert("chr", (vec![Type::new_int()], Type::new_string(), true));
+        functions.insert("size", (vec![Type::new_string()], Type::new_int(), true));
+        functions.insert("substring", (vec![Type::new_string(), Type::new_int(), Type::new_int()], Type::new_string(), true));
+        functions.insert("concat", (vec![Type::new_string(), Type::new_string()], Type::new_string(), true));
+        functions.insert("not", (vec![Type::new_int()], Type::new_int(), true));
+        functions.insert("stringEqual", (vec![Type::new_string(), Type::new_string()], Type::new_int(), true));
+
+        let cont = Type::Var(TyVar::from_symbol(self.type_env.symbol("cont")));
+        functions.insert("printP", (vec![Type::new_string(), cont.clone()], Type::new_answer(), true));
+        functions.insert("flushP", (vec![cont], Type::new_answer(), true));
+        let string_consumer = Type::Var(TyVar::from_symbol(self.type_env.symbol("stringConsumer")));
+        functions.insert("getcharP", (vec![string_consumer], Type::new_answer(), true));
+        functions.insert("exit", (vec![], Type::new_answer(), true));
+
+        functions.insert("allocClass", (vec![Type::new_int()], Type::new_int(), true));
+        functions.insert("allocRecord", (vec![Type::new_int()], Type::new_int(), true));
+        functions.insert("initArray", (vec![Type::new_int(), Type::new_int()], Type::new_int(), true));
         functions
     }
 }

tiger/src/lexer.rs

@@ -189,6 +189,7 @@ impl<R: Read> Lexer<R> {
                 "new" => New,
                 "nil" => Nil,
                 "of" => Of,
+                "poly" => Poly,
                 "pure" => Pure,
                 "then" => Then,
                 "to" => To,