Expr* subst(Expr* e, const Subst& sub) { switch (e->kind) { case id_expr: return e; case unit_term: return e; case true_term: return e; case false_term: return e; case if_term: return subst_ternary_term(as<If>(e), sub); case int_term: return e; case and_term: return subst_binary_term(as<And>(e), sub); case or_term: return subst_binary_term(as<Or>(e), sub); case equals_term: return subst_binary_term(as<Equals>(e), sub); case less_term: return subst_binary_term(as<Less>(e), sub); case not_term: return subst_unary_term(as<Not>(e), sub); case succ_term: return subst_unary_term(as<Succ>(e), sub); case pred_term: return subst_unary_term(as<Pred>(e), sub); case iszero_term: return subst_unary_term(as<Iszero>(e), sub); case var_term: return subst_var(as<Var>(e), sub); case abs_term: return subst_binary_term(as<Abs>(e), sub); case app_term: return subst_binary_term(as<App>(e), sub); case ref_term: return subst_ref(as<Ref>(e), sub); case mem_term: return subst_mem(as<Mem>(e), sub); case kind_type: return e; case unit_type: return e; case bool_type: return e; case nat_type: return e; case arrow_type: return e; case record_term: return e; default: break; } lang_unreachable(format("substitution into unkown term '{}'", node_name(e))); }
// Save the named term t in the current scope. Expr* declare(Expr* t) { if (Var* v = as<Var>(t)) return declare(v->name(), v); if (Def* d = as<Def>(t)) return declare(d->name(), d); lang_unreachable(format("cannot declare expression '{}'", node_name(t))); }
// Returns the integer elaboration of the token. If the token is // not one of the integer tokens, behavior is undefined. Integer as_integer(const Token& k) { lang_assert(token::get_type(k.kind) == token_int_type, format("token '{0}' is not an integer value", k)); switch (k.kind) { case binary_literal_tok: return {k.text, 2}; case octal_literal_tok: return {k.text, 8}; case decimal_literal_tok: return {k.text, 10}; case hexadecimal_literal_tok: return {k.text, 16}; default: break; } lang_unreachable("invalid integer token"); }
// Render the given term into the output stream. void print(std::ostream& os, Tree* t) { if (not t) { os << "<null>"; return; } switch (t->kind) { case id_tree: return pp_terminal(os, as<Id_tree>(t)); case lit_tree: return pp_terminal(os, as<Lit_tree>(t)); case var_tree: return pp_var(os, as<Var_tree>(t)); case init_tree: return pp_init(os, as<Init_tree>(t)); case abs_tree: return pp_abs(os, as<Abs_tree>(t)); case fn_tree: return pp_fn(os, as<Fn_tree>(t)); case app_tree: return pp_app(os, as<App_tree>(t)); case if_tree: return pp_if(os, as<If_tree>(t)); case succ_tree: return pp_succ(os, as<Succ_tree>(t)); case pred_tree: return pp_pred(os, as<Pred_tree>(t)); case ls_tree: return pp_ls(os, as<Ls_tree>(t));//Rishi case mkdir_tree: return pp_mkdir(os, as<Mkdir_tree>(t));//Rishi case rmdir_tree: return pp_rmdir(os, as<Rmdir_tree>(t));//Rishi case cd_tree: return pp_cd(os, as<Cd_tree>(t));//Rishi case mv_tree: return pp_mv(os, as<Mv_tree>(t));//Rishi case iszero_tree: return pp_iszero(os, as<Iszero_tree>(t)); case arrow_tree: return pp_arrow(os, as<Arrow_tree>(t)); case def_tree: return pp_def(os, as<Def_tree>(t)); case print_tree: return pp_print(os, as<Print_tree>(t)); case typeof_tree: return pp_typeof(os, as<Typeof_tree>(t)); case tuple_tree: return pp_tuple(os, as<Tuple_tree>(t)); case list_tree: return pp_list(os, as<List_tree>(t)); case variant_tree: return pp_variant(os, as<Variant_tree>(t)); case comma_tree: return pp_comma(os, as<Comma_tree>(t)); case dot_tree: return pp_dot(os, as<Dot_tree>(t)); case prog_tree: return pp_prog(os, as<Prog_tree>(t)); } lang_unreachable(format("print unknown node '{}'", node_name(t))); }
// Compute the one-step evaluation of the term t. Term* step(Term* t) { lang_unreachable("not implemented"); }