(* Title: Pure/ML/ml_syntax.ML
Author: Makarius
Concrete ML syntax for basic values.
*)
signature ML_SYNTAX =
sig
val reserved_names: string list
val reserved: Name.context
val is_reserved: string -> bool
val is_identifier: string -> bool
val atomic: string -> string
val print_int: int -> string
val print_pair: ('a -> string) -> ('b -> string) -> 'a * 'b -> string
val print_list: ('a -> string) -> 'a list -> string
val print_option: ('a -> string) -> 'a option -> string
val print_symbol_char: Symbol.symbol -> string
val print_symbol: Symbol.symbol -> string
val print_string: string -> string
val print_strings: string list -> string
val print_path: Path.T -> string
val print_platform_path: Path.T -> string
val print_properties: Properties.T -> string
val print_position: Position.T -> string
val print_range: Position.range -> string
val print_path_binding: Path.binding -> string
val make_binding: string * Position.T -> string
val print_indexname: indexname -> string
val print_class: class -> string
val print_sort: sort -> string
val print_typ: typ -> string
val print_term: term -> string
val pretty_string: int -> string -> Pretty.T
end;
structure ML_Syntax: ML_SYNTAX =
struct
(* reserved words *)
val reserved_names = filter Symbol.is_ascii_identifier ML_Lex.keywords;
val reserved = Name.make_context reserved_names;
val is_reserved = Name.is_declared reserved;
(* identifiers *)
fun is_identifier name =
not (is_reserved name) andalso Symbol.is_ascii_identifier name;
(* literal output -- unformatted *)
val atomic = enclose "(" ")";
val print_int = string_of_int;
fun print_pair f1 f2 (x, y) = "(" ^ f1 x ^ ", " ^ f2 y ^ ")";
fun print_list f = enclose "[" "]" o commas o map f;
fun print_option f NONE = "NONE"
| print_option f (SOME x) = "SOME (" ^ f x ^ ")";
fun print_symbol_char s =
if Symbol.is_char s then
(case ord s of
34 => "\\\""
| 92 => "\\\\"
| 7 => "\\a"
| 8 => "\\b"
| 9 => "\\t"
| 10 => "\\n"
| 11 => "\\v"
| 12 => "\\f"
| 13 => "\\r"
| c =>
if c < 32 then "\\^" ^ chr (c + 64)
else if c < 127 then s
else "\\" ^ string_of_int c)
else error ("Bad character: " ^ quote s);
fun print_symbol s =
if Symbol.is_char s then print_symbol_char s
else if Symbol.is_utf8 s then translate_string print_symbol_char s
else s;
val print_string = quote o implode o map print_symbol o Symbol.explode;
val print_strings = print_list print_string;
fun print_path path =
"Path.explode " ^ print_string (Path.implode path);
val print_platform_path = print_string o File.platform_path;
val print_properties = print_list (print_pair print_string print_string);
fun print_position pos =
"Position.of_properties " ^ print_properties (Position.properties_of pos);
fun print_range range =
"Position.range_of_properties " ^ print_properties (Position.properties_of_range range);
fun print_path_binding binding =
"Path.binding " ^ print_pair print_path print_position (Path.dest_binding binding);
fun make_binding (name, pos) =
"Binding.make " ^ print_pair print_string print_position (name, pos);
val print_indexname = print_pair print_string print_int;
val print_class = print_string;
val print_sort = print_list print_class;
fun print_typ (Type arg) = "Term.Type " ^ print_pair print_string (print_list print_typ) arg
| print_typ (TFree arg) = "Term.TFree " ^ print_pair print_string print_sort arg
| print_typ (TVar arg) = "Term.TVar " ^ print_pair print_indexname print_sort arg;
fun print_term (Const arg) = "Term.Const " ^ print_pair print_string print_typ arg
| print_term (Free arg) = "Term.Free " ^ print_pair print_string print_typ arg
| print_term (Var arg) = "Term.Var " ^ print_pair print_indexname print_typ arg
| print_term (Bound i) = "Term.Bound " ^ print_int i
| print_term (Abs (s, T, t)) =
"Term.Abs (" ^ print_string s ^ ", " ^ print_typ T ^ ", " ^ print_term t ^ ")"
| print_term (t1 $ t2) = "Term.$ " ^ print_pair print_term print_term (t1, t2);
(* toplevel pretty printing *)
fun pretty_string max_len str =
let
val body =
if YXML.is_wellformed str then
maps (fn XML.Elem _ => [""] | XML.Text s => Symbol.explode s) (YXML.parse_body str)
else Symbol.explode str;
val body' =
if length body <= max_len then body
else take (Int.max (max_len, 0)) body @ ["..."];
in Pretty.str (quote (implode (map print_symbol body'))) end;
val _ =
ML_system_pp (fn depth => fn _ => fn str =>
Pretty.to_polyml (pretty_string (FixedInt.toInt (depth * 100)) str));
end;
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