vm_obj tactic_get_subsingleton_info(vm_obj const & fn, vm_obj const & n, vm_obj const & m, vm_obj const & s) {
TRY;
type_context ctx = mk_type_context_for(s, m);
if (is_none(n)) {
return mk_result(get_subsingleton_info(ctx, to_expr(fn)), s);
} else {
return mk_result(get_subsingleton_info(ctx, to_expr(fn), force_to_unsigned(get_some_value(n), 0)), s);
}
CATCH;
}
static void trace_if_unsupported(type_context & ctx, expr const & fn,
buffer<expr> const & args, unsigned prefix_sz, ss_param_infos const & result) {
lean_assert(args.size() >= length(result));
if (!is_fun_info_trace_enabled())
return;
fun_info info = get_fun_info(ctx, fn, args.size());
buffer<param_info> pinfos;
to_buffer(info.get_params_info(), pinfos);
buffer<ss_param_info> ssinfos;
to_buffer(get_subsingleton_info(ctx, fn, args.size()), ssinfos);
lean_assert(pinfos.size() == ssinfos.size());
/* Check if all remaining arguments are nondependent or
dependent (but all forward dependencies are subsingletons) */
unsigned i = prefix_sz;
for (; i < pinfos.size(); i++) {
param_info const & pinfo = pinfos[i];
if (!pinfo.has_fwd_deps())
continue; /* nondependent argument */
if (has_nonsubsingleton_fwd_dep(i, pinfos, ssinfos))
break; /* failed i-th argument has a forward dependent that is not a prop nor a subsingleton */
}
if (i == pinfos.size())
return; // It is *cheap* case
/* Expensive case */
/* We generate a trace message IF it would be possible to compute more precise information.
That is, there is an argument that is a proposition and/or subsingleton, but
the corresponding pinfo is not a marked a prop/subsingleton.
*/
i = 0;
for (ss_param_info const & ssinfo : result) {
if (ssinfo.is_subsingleton())
continue;
expr arg_type = ctx.infer(args[i]);
if (ctx.mk_subsingleton_instance(arg_type)) {
lean_trace_fun_info(
tout() << "approximating function information for '" << fn
<< "', this may affect the effectiveness of the simplifier and congruence closure modules, "
<< "more precise information can be efficiently computed if all parameters are moved to the "
<< "beginning of the function\n";);
return;
}
