lean4-htt/src/library/tactic/exact_tactic.cpp

48 lines
1.6 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 "library/vm/vm_expr.h"
#include "library/tactic/tactic_state.h"
#include "library/tactic/app_builder_tactics.h"
namespace lean {
vm_obj exact(expr const & e, transparency_mode const & m, tactic_state const & s) {
try {
optional<metavar_decl> g = s.get_main_goal_decl();
if (!g) return mk_no_goals_exception(s);
type_context ctx = mk_type_context_for(s, m);
expr e_type = ctx.infer(e);
if (!ctx.is_def_eq(g->get_type(), e_type)) {
auto thunk = [=]() {
format r("exact tactic failed, type mismatch, given expression has type");
unsigned indent = get_pp_indent(s.get_options());
r += nest(indent, line() + pp_expr(s, e_type));
r += line() + format("but is expected to have type");
r += nest(indent, line() + pp_expr(s, g->get_type()));
return r;
};
return tactic::mk_exception(thunk, s);
}
auto mctx = ctx.mctx();
mctx.assign(head(s.goals()), e);
return tactic::mk_success(set_mctx_goals(s, mctx, tail(s.goals())));
} catch (exception & ex) {
return tactic::mk_exception(ex, s);
}
}
vm_obj tactic_exact(vm_obj const & e, vm_obj const & m, vm_obj const & s) {
return exact(to_expr(e), to_transparency_mode(m), tactic::to_state(s));
}
void initialize_exact_tactic() {
DECLARE_VM_BUILTIN(name({"tactic", "exact"}), tactic_exact);
}
void finalize_exact_tactic() {
}
}