lean2/src/library/placeholder.cpp
Leonardo de Moura d79b2babd3 fix(*): typo
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-12-02 08:46:47 -08:00

56 lines
1.5 KiB
C++

/*
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include "kernel/occurs.h"
#include "kernel/metavar.h"
#include "kernel/expr_maps.h"
#include "kernel/replace_visitor.h"
#include "library/placeholder.h"
namespace lean {
static name g_placeholder_name("_");
expr mk_placeholder() {
return mk_constant(g_placeholder_name);
}
bool is_placeholder(expr const & e) {
return is_constant(e) && const_name(e) == g_placeholder_name;
}
bool has_placeholder(expr const & e) {
return occurs(mk_placeholder(), e);
}
class replace_placeholders_with_metavars_proc : public replace_visitor {
metavar_env & m_menv;
expr_map<expr> * m_new2old;
protected:
expr visit_constant(expr const & e, context const & c) {
if (is_placeholder(e)) {
return m_menv.mk_metavar(c);
} else {
return e;
}
}
expr visit(expr const & e, context const & c) {
expr r = replace_visitor::visit(e, c);
if (!is_eqp(r, e) && m_new2old)
(*m_new2old)[r] = e;
return r;
}
public:
replace_placeholders_with_metavars_proc(metavar_env & menv, expr_map<expr> * new2old):
m_menv(menv),
m_new2old(new2old) {
}
};
expr replace_placeholders_with_metavars(expr const & e, metavar_env & menv, expr_map<expr> * new2old) {
replace_placeholders_with_metavars_proc proc(menv, new2old);
return proc(e);
}
}