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#pragma once
#include <memory>
#include <map>
#include <string>
#include <vector>
#include <set>
#include <optional>
#include "location.hh"
class type_mgr;
struct type {
virtual ~type() = default;
virtual void print(const type_mgr& mgr, std::ostream& to) const = 0;
};
using type_ptr = std::shared_ptr<type>;
struct type_scheme {
std::vector<std::string> forall;
type_ptr monotype;
type_scheme(type_ptr type) : forall(), monotype(std::move(type)) {}
void print(const type_mgr& mgr, std::ostream& to) const;
type_ptr instantiate(type_mgr& mgr) const;
};
using type_scheme_ptr = std::shared_ptr<type_scheme>;
struct type_var : public type {
std::string name;
type_var(std::string n)
: name(std::move(n)) {}
void print(const type_mgr& mgr, std::ostream& to) const;
};
struct type_base : public type {
std::string name;
int32_t arity;
type_base(std::string n, int32_t a = 0)
: name(std::move(n)), arity(a) {}
void print(const type_mgr& mgr, std::ostream& to) const;
};
struct type_data : public type_base {
struct constructor {
int tag;
};
std::map<std::string, constructor> constructors;
type_data(std::string n, int32_t a = 0)
: type_base(std::move(n), a) {}
};
struct type_arr : public type {
type_ptr left;
type_ptr right;
type_arr(type_ptr l, type_ptr r)
: left(std::move(l)), right(std::move(r)) {}
void print(const type_mgr& mgr, std::ostream& to) const;
};
struct type_app : public type {
type_ptr constructor;
std::vector<type_ptr> arguments;
type_app(type_ptr c)
: constructor(std::move(c)) {}
void print(const type_mgr& mgr, std::ostream& to) const;
};
class type_mgr {
private:
int last_id = 0;
std::map<std::string, type_ptr> types;
public:
std::string new_type_name();
type_ptr new_type();
type_ptr new_arrow_type();
void unify(type_ptr l, type_ptr r, const std::optional<yy::location>& loc = std::nullopt);
type_ptr substitute(
const std::map<std::string, type_ptr>& subst,
const type_ptr& t) const;
type_ptr lookup(const std::string& var) const;
type_ptr resolve(type_ptr t, type_var*& var) const;
void bind(const std::string& s, type_ptr t);
void find_free(const type_ptr& t, std::set<std::string>& into) const;
void find_free(const type_scheme_ptr& t, std::set<std::string>& into) const;
};