lean2/src/kernel/replace_visitor.cpp

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/*
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
2013-10-26 18:07:06 +00:00
#include <tuple>
#include "util/interrupt.h"
#include "util/freset.h"
#include "kernel/replace_visitor.h"
namespace lean {
expr replace_visitor::visit_type(expr const & e, context const &) { lean_assert(is_type(e)); return e; }
expr replace_visitor::visit_value(expr const & e, context const &) { lean_assert(is_value(e)); return e; }
expr replace_visitor::visit_var(expr const & e, context const &) { lean_assert(is_var(e)); return e; }
expr replace_visitor::visit_metavar(expr const & e, context const &) { lean_assert(is_metavar(e)); return e; }
expr replace_visitor::visit_constant(expr const & e, context const & ctx) {
lean_assert(is_constant(e));
return update_const(e, visit(const_type(e), ctx));
}
expr replace_visitor::visit_pair(expr const & e, context const & ctx) {
lean_assert(is_pair(e));
return update_pair(e, [&](expr const & f, expr const & s, expr const & t) {
return std::make_tuple(visit(f, ctx), visit(s, ctx), visit(t, ctx));
});
}
expr replace_visitor::visit_proj(expr const & e, context const & ctx) {
return update_proj(e, visit(proj_arg(e), ctx));
}
expr replace_visitor::visit_app(expr const & e, context const & ctx) {
lean_assert(is_app(e));
return update_app(e, [&](expr const & c) { return visit(c, ctx); });
}
expr replace_visitor::visit_abst(expr const & e, context const & ctx) {
lean_assert(is_abstraction(e));
return update_abst(e, [&](expr const & t, expr const & b) {
expr new_t = visit(t, ctx);
{
freset<cache> reset(m_cache);
expr new_b = visit(b, extend(ctx, abst_name(e), new_t));
return std::make_pair(new_t, new_b);
}
});
}
expr replace_visitor::visit_lambda(expr const & e, context const & ctx) {
lean_assert(is_lambda(e));
return visit_abst(e, ctx);
}
expr replace_visitor::visit_pi(expr const & e, context const & ctx) {
lean_assert(is_pi(e));
return visit_abst(e, ctx);
}
expr replace_visitor::visit_sigma(expr const & e, context const & ctx) {
lean_assert(is_sigma(e));
return visit_abst(e, ctx);
}
expr replace_visitor::visit_let(expr const & e, context const & ctx) {
lean_assert(is_let(e));
return update_let(e, [&](optional<expr> const & t, expr const & v, expr const & b) {
optional<expr> new_t = visit(t, ctx);
expr new_v = visit(v, ctx);
{
freset<cache> reset(m_cache);
expr new_b = visit(b, extend(ctx, let_name(e), new_t, new_v));
return std::make_tuple(new_t, new_v, new_b);
}
});
}
expr replace_visitor::save_result(expr const & e, expr && r, bool shared) {
if (shared)
m_cache.insert(std::make_pair(e, r));
return r;
}
expr replace_visitor::visit(expr const & e, context const & ctx) {
check_system("expression replacer");
bool shared = false;
if (is_shared(e)) {
shared = true;
auto it = m_cache.find(e);
if (it != m_cache.end())
return it->second;
}
switch (e.kind()) {
case expr_kind::Type: return save_result(e, visit_type(e, ctx), shared);
case expr_kind::Value: return save_result(e, visit_value(e, ctx), shared);
case expr_kind::Constant: return save_result(e, visit_constant(e, ctx), shared);
case expr_kind::Var: return save_result(e, visit_var(e, ctx), shared);
case expr_kind::MetaVar: return save_result(e, visit_metavar(e, ctx), shared);
case expr_kind::Pair: return save_result(e, visit_pair(e, ctx), shared);
case expr_kind::Proj: return save_result(e, visit_proj(e, ctx), shared);
case expr_kind::App: return save_result(e, visit_app(e, ctx), shared);
case expr_kind::Lambda: return save_result(e, visit_lambda(e, ctx), shared);
case expr_kind::Pi: return save_result(e, visit_pi(e, ctx), shared);
case expr_kind::Sigma: return save_result(e, visit_sigma(e, ctx), shared);
case expr_kind::Let: return save_result(e, visit_let(e, ctx), shared);
}
lean_unreachable(); // LCOV_EXCL_LINE
}
optional<expr> replace_visitor::visit(optional<expr> const & e, context const & ctx) {
if (e)
return some_expr(visit(*e, ctx));
else
return none_expr();
}
}