lean2/src/library/placeholder.cpp
2013-09-19 22:40:34 -07:00

42 lines
1.1 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.h"
#include "library/placeholder.h"
#include "library/replace_using_ctx.h"
namespace lean {
static name g_placeholder_name("_");
expr mk_placholder() {
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_placholder(), e);
}
expr replace_placeholders_with_metavars(expr const & e, metavar_env & menv, expr_map<expr> * trace) {
auto f = [&](expr const & e, context const & ctx, unsigned) -> expr {
if (is_placeholder(e)) {
return menv.mk_metavar(ctx);
} else {
return e;
}
};
auto p = [&](expr const & s, expr const & t) {
if (trace)
(*trace)[t] = s;
};
return replace_using_ctx_fn<decltype(f), decltype(p)>(f, p)(e);
}
}