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yap/sketch.cpp
2016-12-07 20:01:13 -06:00

634 lines
17 KiB
C++

#include <boost/hana/integral_constant.hpp>
#include <boost/hana/tuple.hpp>
#include <boost/hana/type.hpp>
#include <boost/hana/size.hpp>
// TODO: Pretty printer.
// TODO: Verbose debugging mode for matching.
// TODO: Proto-style "Fuzzy and Exact Matches of Terminals".
namespace boost { namespace proto17 {
enum class expr_kind {
terminal,
plus,
minus,
// etc...
};
template <expr_kind Kind, typename ...T>
struct expression;
template <typename T>
struct terminal;
namespace detail {
template <typename T>
struct partial_decay
{
using type = T;
};
template <typename T>
struct partial_decay<T[]> { using type = T *; };
template <typename T, std::size_t N>
struct partial_decay<T[N]> { using type = T *; };
template <typename T>
struct partial_decay<T(&)[]> { using type = T *; };
template <typename T, std::size_t N>
struct partial_decay<T(&)[N]> { using type = T *; };
template <typename R, typename ...A>
struct partial_decay<R(A...)> { using type = R(*)(A...); };
template <typename R, typename ...A>
struct partial_decay<R(A..., ...)> { using type = R(*)(A..., ...); };
template <typename T,
typename U = typename detail::partial_decay<T>::type,
bool AddRValueRef = std::is_same_v<T, U> && !std::is_const_v<U>>
struct rhs_value_type_phase_1;
template <typename T, typename U>
struct rhs_value_type_phase_1<T, U, true>
{ using type = U &&; };
template <typename T, typename U>
struct rhs_value_type_phase_1<T, U, false>
{ using type = U; };
template <typename T>
struct is_terminal
{ static bool const value = false; };
template <typename T>
struct is_terminal<terminal<T>>
{ static bool const value = true; };
template <typename T,
typename U = typename rhs_value_type_phase_1<T>::type,
bool RemoveRefs = std::is_rvalue_reference_v<U>,
bool IsTerminal = is_terminal<std::decay_t<T>>::value>
struct rhs_type;
template <typename T, typename U, bool RemoveRefs>
struct rhs_type<T, U, RemoveRefs, true>
{ using type = T; };
template <typename T, typename U>
struct rhs_type<T, U, true, false>
{ using type = terminal<std::remove_reference_t<U>>; };
template <typename T, typename U>
struct rhs_type<T, U, false, false>
{ using type = terminal<U>; };
}
#if 0 // TODO
struct callable
{
auto operator() (TODO) const;
};
#endif
// TODO: May be a Callable.
template <typename T>
struct terminal
{
T value;
template <typename U>
auto operator+ (U && rhs) &
{
using rhs_type = typename detail::rhs_type<U>::type;
return expression<expr_kind::plus, terminal<T> &, rhs_type>{
hana::tuple<terminal<T> &, rhs_type>(*this, rhs_type{static_cast<U &&>(rhs)})
};
}
#if 0
template <typename U>
auto operator+ (U && rhs) const &
{
return expression<expr_kind::plus, terminal<T> const &, hana::detail::decay(rhs)>{
hana::tuple<terminal<T> const &, hana::detail::decay(rhs)>(*this, std::forward<U>(rhs))
};
}
template <typename U>
auto operator+ (U && rhs) &&
{
return expression<expr_kind::plus, terminal<T> &&, hana::detail::decay(rhs)>{
hana::tuple<terminal<T> &&, hana::detail::decay(rhs)>(
static_cast<terminal<T> &&>(*this),
std::forward<U>(rhs)
)
};
}
#endif
};
template <typename T>
constexpr bool is_terminal (hana::basic_type<T>)
{ return false; }
template <typename T>
constexpr bool is_terminal (hana::basic_type<terminal<T>>)
{ return true; }
template <expr_kind Kind, typename T>
constexpr bool is_expression (hana::basic_type<T>)
{ return false; }
template <expr_kind Kind, typename ...T>
constexpr bool is_expression (hana::basic_type<expression<Kind, T...>>)
{ return true; }
template <expr_kind Kind, typename ...T>
struct expression
{
static const expr_kind kind = Kind;
hana::tuple<T...> elements;
};
template <long long I>
struct placeholder : hana::llong<I> {};
namespace literals {
template <char ...c>
constexpr auto operator"" _p ()
{ return placeholder<hana::ic_detail::parse<sizeof...(c)>({c...})>{}; }
}
namespace match {
template <typename KindMatches, typename ...T>
struct expression
{
KindMatches kind_matches;
hana::tuple<T...> elements;
};
// TODO: Use this to detect identical types within a match.
template <long long I>
struct placeholder : hana::llong<I> {};
}
template <typename KindMatches, typename T>
constexpr bool is_match_expression (hana::basic_type<T>)
{ return false; }
template <typename KindMatches, typename ...T>
constexpr bool is_match_expression (hana::basic_type<match::expression<KindMatches, T...>>)
{ return true; }
namespace literals {
template <char ...c>
constexpr auto operator"" _T ()
{ return match::placeholder<hana::ic_detail::parse<sizeof...(c)>({c...})>{}; }
}
namespace detail {
inline bool matches (...)
{ return false; }
template <typename MatchExpr, typename TreeExpr>
bool matches (MatchExpr const & match_subtree, TreeExpr const & subtree);
template <std::size_t I, typename MatchExpr, typename TreeExpr>
void recursive_match_impl (MatchExpr const & match_subtree, TreeExpr const & subtree, bool & result)
{
if (!matches(match_subtree[hana::size_c<I>], subtree[hana::size_c<I>])) {
result = false;
}
if constexpr (0 < I) {
recursive_match_impl<I - 1>(match_subtree, subtree, result);
}
}
template <typename MatchExpr, typename TreeExpr>
bool matches (MatchExpr const & match_subtree, TreeExpr const & subtree)
{
static_assert(is_match_expression(hana::typeid_(match_subtree)),
"Attempted to use a non-tree as a match expression.");
static_assert(is_expression(hana::typeid_(subtree)),
"Attempted to use find a match in a non-tree.");
// TODO: Verbose mode.
if (!match_subtree.kind_matches(subtree)) {
return false;
} else {
auto constexpr subtree_size = hana::size(subtree.elements);
if constexpr (hana::size(match_subtree.elements) != subtree_size) {
// TODO: Verbose mode.
return false;
} else {
bool children_match = true;
recursive_match_impl<subtree_size - 1>(
match_subtree.elements,
subtree.elements,
children_match
);
return children_match;
}
}
}
template <typename Matcher, typename Callable, expr_kind Kind, typename ...T>
auto mutate_subtrees_of (
Matcher const & match_subtree,
expression<Kind, T...> & tree,
Callable && mutation
) {
// TODO: Process children first.
if (matches(match_subtree, tree)) {
return mutation(tree);
} else if (Kind == expr_kind::terminal) {
return tree;
} else {
auto mutate_child = [&match_subtree, &mutation] (auto & t) {
return mutate_subtrees_of(match_subtree, t, static_cast<Callable &&>(mutation));
};
auto return_elements = hana::transform(tree.elements, mutate_child);
return make_expression(Kind, std::move(return_elements));
}
}
}
} }
#include <string>
template <typename T>
using term = boost::proto17::terminal<T>;
namespace bp17 = boost::proto17;
using namespace std::string_literals;
void term_plus_x ()
{
// char const * string
{
term<double> unity{1.0};
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<char const *>
> unevaluated_expr = unity + "3";
}
// std::string temporary
{
term<double> unity{1.0};
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<std::string>
> unevaluated_expr = unity + "3"s;
}
// arrays
{
term<double> unity{1.0};
int ints[] = {1, 2};
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int *>
> unevaluated_expr = unity + ints;
}
{
term<double> unity{1.0};
int const ints[] = {1, 2};
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int const *>
> unevaluated_expr = unity + ints;
}
{
term<double> unity{1.0};
int ints[] = {1, 2};
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int *>
> unevaluated_expr = unity + std::move(ints);
}
// pointers
{
term<double> unity{1.0};
int ints[] = {1, 2};
int * int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int * &>
> unevaluated_expr = unity + int_ptr;
}
{
term<double> unity{1.0};
int const ints[] = {1, 2};
int const * int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int const * &>
> unevaluated_expr = unity + int_ptr;
}
{
term<double> unity{1.0};
int ints[] = {1, 2};
int * int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int *>
> unevaluated_expr = unity + std::move(int_ptr);
}
// const pointers
{
term<double> unity{1.0};
int ints[] = {1, 2};
int * const int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int * const &>
> unevaluated_expr = unity + int_ptr;
}
{
term<double> unity{1.0};
int const ints[] = {1, 2};
int const * const int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int const * const &>
> unevaluated_expr = unity + int_ptr;
}
{
term<double> unity{1.0};
int ints[] = {1, 2};
int * const int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int * const>
> unevaluated_expr = unity + std::move(int_ptr);
}
// values
{
term<double> unity{1.0};
int i = 1;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int &>
> unevaluated_expr = unity + i;
}
{
term<double> unity{1.0};
int const i = 1;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int const &>
> unevaluated_expr = unity + i;
}
{
term<double> unity{1.0};
int i = 1;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int>
> unevaluated_expr = unity + std::move(i);
}
}
void term_plus_term ()
{
// char const * string
{
term<double> unity{1.0};
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<char const *>
> unevaluated_expr = unity + term<char const *>{"3"};
}
// std::string temporary
{
term<double> unity{1.0};
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<std::string>
> unevaluated_expr = unity + term<std::string>{"3"s};
}
// arrays
{
term<double> unity{1.0};
int ints_[] = {1, 2};
term<int *> ints = {ints_};
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int *>
> unevaluated_expr = unity + ints;
}
{
term<double> unity{1.0};
int const ints_[] = {1, 2};
term<int const *> ints = {ints_};
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int const *>
> unevaluated_expr = unity + ints;
}
{
term<double> unity{1.0};
int ints_[] = {1, 2};
term<int *> ints = {ints_};
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int *>
> unevaluated_expr = unity + std::move(ints);
}
// pointers
{
term<double> unity{1.0};
int ints[] = {1, 2};
int * int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int * &>
> unevaluated_expr = unity + int_ptr;
}
{
term<double> unity{1.0};
int const ints[] = {1, 2};
int const * int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int const * &>
> unevaluated_expr = unity + int_ptr;
}
{
term<double> unity{1.0};
int ints[] = {1, 2};
int * int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int *>
> unevaluated_expr = unity + std::move(int_ptr);
}
// const pointers
{
term<double> unity{1.0};
int ints[] = {1, 2};
int * const int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int * const &>
> unevaluated_expr = unity + int_ptr;
}
{
term<double> unity{1.0};
int const ints[] = {1, 2};
int const * const int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int const * const &>
> unevaluated_expr = unity + int_ptr;
}
{
term<double> unity{1.0};
int ints[] = {1, 2};
int * const int_ptr = ints;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int * const>
> unevaluated_expr = unity + std::move(int_ptr);
}
// values
{
term<double> unity{1.0};
int i = 1;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int &>
> unevaluated_expr = unity + i;
}
{
term<double> unity{1.0};
int const i = 1;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int const &>
> unevaluated_expr = unity + i;
}
{
term<double> unity{1.0};
int i = 1;
bp17::expression<
bp17::expr_kind::plus,
term<double> &,
term<int>
> unevaluated_expr = unity + std::move(i);
}
}
int main ()
{
term_plus_x();
term_plus_term();
#if 0 // TODO
{
bp17::terminal<double> unity{1.0};
auto unevaluated_expr = unity + "3";
auto mutated_expr = mutate(unevaluated_expr, match_expr, mutation);
auto result = bp17::eval(unevaluated_expr);
}
{
bp17::terminal<double> a{1.0};
bp17::terminal<double> x{2.0};
bp17::terminal<int> b{3};
auto unevaluated_expr = a * x + b;
auto match_expr = 0_T * 0_T + 1_T;
auto mutated_expr = mutate(unevaluated_expr, match_expr, mutation);
auto result = bp17::eval(mutated_expr);
}
{
bp17::terminal<double> a{1.0};
bp17::terminal<double> x{2.0};
bp17::terminal<int> b{3};
auto match_double_2 = [] (auto && terminal) {
if constexpr (hana::typeid_(terminal) == hana::type<double>{})
return terminal == 2.0;
else
return false;
};
auto unevaluated_expr = a * x + b;
auto match_expr = bp17::match<double> * match_double_2 + 0_T;
auto mutated_expr = mutate(unevaluated_expr, match_expr, mutation);
auto result = bp17::eval(mutated_expr);
}
#endif
}