lean4-htt/src/library/quote.cpp
2017-05-19 14:17:06 +02:00

184 lines
7 KiB
C++

/*
Copyright (c) 2016 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <string>
#include "util/fresh_name.h"
#include "kernel/abstract.h"
#include "kernel/replace_fn.h"
#include "library/placeholder.h"
#include "library/constants.h"
#include "library/annotation.h"
#include "library/kernel_serializer.h"
#include "library/exception.h"
#include "library/util.h"
#include "library/quote.h"
#include "library/type_context.h"
namespace lean {
static std::string * g_expr_quote_opcode = nullptr;
static std::string * g_pexpr_quote_opcode = nullptr;
static expr * g_expr = nullptr;
static expr * g_pexpr = nullptr;
static name * g_expr_quote_macro = nullptr;
static name * g_pexpr_quote_macro = nullptr;
/** \brief The quoted expression macro is a compact way of encoding quoted expressions inside Lean expressions.
It is used to represent values of types `reflected e` or `expr`. */
class expr_quote_macro : public macro_definition_cell {
public:
virtual name get_name() const { return *g_expr_quote_macro; }
virtual expr check_type(expr const & m, abstract_type_context & ctx, bool infer_only) const {
expr const & e = get_expr_quote_value(m);
expr ty = ctx.check(e, infer_only);
return mk_app(mk_constant(get_reflected_name(), {get_level(ctx, ty)}), ty, e);
}
virtual optional<expr> expand(expr const &, abstract_type_context &) const {
return optional<expr>();
}
virtual unsigned trust_level() const { return 0; }
virtual void display(std::ostream & out) const {
out << "quote";
}
virtual format pp(formatter const &) const {
return format("quote");
}
virtual bool is_atomic_pp(bool, bool) const { return false; }
virtual void write(serializer & s) const { s << *g_expr_quote_opcode; }
};
/** \brief A compact way of encoding quoted pre-expressions inside Lean expressions. */
class pexpr_quote_macro : public macro_definition_cell {
expr m_value;
public:
pexpr_quote_macro(expr const & v):m_value(v) {}
virtual bool lt(macro_definition_cell const & d) const {
return m_value < static_cast<pexpr_quote_macro const &>(d).m_value;
}
virtual name get_name() const { return *g_pexpr_quote_macro; }
virtual expr check_type(expr const &, abstract_type_context &, bool) const {
return *g_pexpr;
}
virtual optional<expr> expand(expr const &, abstract_type_context &) const {
return optional<expr>();
}
virtual unsigned trust_level() const { return 0; }
virtual bool operator==(macro_definition_cell const & other) const {
/* Hack: we do *not* compare m_value's because quoted expressions may contain
relevant position information that is ignored by the equality predicate for expressions.
*/
return this == &other;
}
char const * prefix() const {
return "``(";
}
virtual void display(std::ostream & out) const {
out << "``(" << m_value << ")";
}
virtual format pp(formatter const & fmt) const {
return format("``(") + nest(2, fmt(m_value)) + format(")");
}
virtual bool is_atomic_pp(bool, bool) const { return false; }
virtual unsigned hash() const { return m_value.hash(); }
virtual void write(serializer & s) const { s << *g_pexpr_quote_opcode << m_value; }
expr const & get_value() const { return m_value; }
};
expr mk_expr_quote(expr const & e) {
return mk_macro(macro_definition(new expr_quote_macro()), 1, &e);
}
expr mk_pexpr_quote(expr const & e) {
return mk_macro(macro_definition(new pexpr_quote_macro(e)));
}
bool is_expr_quote(expr const & e) {
return is_macro(e) && dynamic_cast<expr_quote_macro const *>(macro_def(e).raw()) != nullptr;
}
bool is_pexpr_quote(expr const & e) {
return is_macro(e) && dynamic_cast<pexpr_quote_macro const *>(macro_def(e).raw()) != nullptr;
}
expr const & get_expr_quote_value(expr const & e) {
lean_assert(is_expr_quote(e));
return macro_arg(e, 0);
}
expr const & get_pexpr_quote_value(expr const & e) {
lean_assert(is_pexpr_quote(e));
return static_cast<pexpr_quote_macro const *>(macro_def(e).raw())->get_value();
}
static name * g_antiquote = nullptr;
expr mk_antiquote(expr const & e) { return mk_annotation(*g_antiquote, e); }
bool is_antiquote(expr const & e) { return is_annotation(e, *g_antiquote); }
expr const & get_antiquote_expr(expr const & e) {
lean_assert(is_antiquote(e));
return get_annotation_arg(e);
}
expr mk_pexpr_quote_and_substs(expr const & e, bool is_strict) {
name x("_x");
buffer<expr> locals;
buffer<expr> aqs;
expr s = replace(e, [&](expr const & t, unsigned) {
if (is_antiquote(t)) {
expr local = mk_local(mk_fresh_name(), x.append_after(locals.size() + 1),
mk_expr_placeholder(), binder_info());
locals.push_back(local);
aqs.push_back(get_antiquote_expr(t));
return some_expr(local);
}
if (is_local(t) && is_strict) {
throw generic_exception(t, "unexpected local in quotation expression");
}
return none_expr();
});
expr r = mk_pexpr_quote(Fun(locals, s));
expr subst = mk_constant(get_expr_subst_name());
expr to_pexpr = mk_constant(get_to_pexpr_name());
for (expr const & aq : aqs) {
r = mk_app(subst, r, mk_app(to_pexpr, aq));
}
return r;
}
void initialize_quote() {
g_expr_quote_macro = new name("expr_quote_macro");
g_pexpr_quote_macro = new name("pexpr_quote_macro");
g_expr_quote_opcode = new std::string("Quote");
g_pexpr_quote_opcode = new std::string("PQuote");
g_expr = new expr(mk_app(Const(get_expr_name()), mk_bool_tt()));
g_pexpr = new expr(mk_app(Const(get_expr_name()), mk_bool_ff()));
g_antiquote = new name("antiquote");
register_annotation(*g_antiquote);
register_macro_deserializer(*g_expr_quote_opcode,
[](deserializer &, unsigned num, expr const * args) {
if (num != 1)
throw corrupted_stream_exception();
return mk_expr_quote(args[0]);
});
register_macro_deserializer(*g_pexpr_quote_opcode,
[](deserializer & d, unsigned num, expr const *) {
if (num != 0)
throw corrupted_stream_exception();
expr e;
d >> e;
return mk_pexpr_quote(e);
});
}
void finalize_quote() {
delete g_expr_quote_macro;
delete g_pexpr_quote_macro;
delete g_expr_quote_opcode;
delete g_pexpr_quote_opcode;
delete g_expr;
delete g_pexpr;
delete g_antiquote;
}
}