/* Given a cases_on application, distribute extra arguments over minor premisses. cases_on major minor_1 ... minor_n a_1 ... a_n We apply a similar transformation at erase_irrelevant, but its effect can be undone in subsequent compilation steps. */ void distribute_extra_args_over_minors(name const & I_name, buffer<name> const & cnames, buffer<expr> & args) { lean_assert(args.size() > cnames.size() + 1); unsigned nparams = *inductive::get_num_params(env(), I_name); for (unsigned i = 0; i < cnames.size(); i++) { unsigned carity = get_constructor_arity(env(), cnames[i]); unsigned data_sz = carity - nparams; type_context::tmp_locals locals(ctx()); expr new_minor = args[i+1]; for (unsigned j = 0; j < data_sz; j++) { if (!is_lambda(new_minor)) throw exception("unexpected occurrence of 'cases_on' expression, " "the minor premise is expected to be a lambda-expression"); expr local = locals.push_local_from_binding(new_minor); new_minor = instantiate(binding_body(new_minor), local); } new_minor = beta_reduce(mk_app(new_minor, args.size() - cnames.size() - 1, args.data() + cnames.size() + 1)); args[i+1] = locals.mk_lambda(new_minor); } args.shrink(cnames.size() + 1); }
/** \brief Given a sequence metas: <tt>(?m_1 ...) (?m_2 ... ) ... (?m_k ...)</tt>, we say ?m_i is "redundant" if it occurs in the type of some ?m_j. This procedure removes from metas any redundant element. */ static void remove_redundant_metas(buffer<expr> & metas) { buffer<expr> mvars; for (expr const & m : metas) mvars.push_back(get_app_fn(m)); unsigned k = 0; for (unsigned i = 0; i < metas.size(); i++) { bool found = false; for (unsigned j = 0; j < metas.size(); j++) { if (j != i) { if (occurs(mvars[i], mlocal_type(mvars[j]))) { found = true; break; } } } if (!found) { metas[k] = metas[i]; k++; } } metas.shrink(k); }