1 (* Title: Pure/General/ml_syntax.ML
5 Basic ML syntax operations.
10 val reserved_names: string list
11 val reserved: Name.context
12 val is_reserved: string -> bool
13 val is_identifier: string -> bool
14 val atomic: string -> string
15 val print_int: int -> string
16 val print_pair: ('a -> string) -> ('b -> string) -> 'a * 'b -> string
17 val print_list: ('a -> string) -> 'a list -> string
18 val print_option: ('a -> string) -> 'a option -> string
19 val print_char: string -> string
20 val print_string: string -> string
21 val print_strings: string list -> string
22 val print_indexname: indexname -> string
23 val print_class: class -> string
24 val print_sort: sort -> string
25 val print_typ: typ -> string
26 val print_term: term -> string
29 structure ML_Syntax: ML_SYNTAX =
35 ["abstype", "and", "andalso", "as", "case", "do", "datatype", "else",
36 "end", "exception", "fn", "fun", "handle", "if", "in", "infix",
37 "infixr", "let", "local", "nonfix", "of", "op", "open", "orelse",
38 "raise", "rec", "then", "type", "val", "with", "withtype", "while",
39 "eqtype", "functor", "include", "sharing", "sig", "signature",
40 "struct", "structure", "where"];
42 val reserved = Name.make_context reserved_names;
43 val is_reserved = Name.is_declared reserved;
48 fun is_identifier name =
49 not (is_reserved name) andalso Syntax.is_ascii_identifier name;
52 (* literal output -- unformatted *)
54 val atomic = enclose "(" ")";
56 val print_int = Int.toString;
58 fun print_pair f1 f2 (x, y) = "(" ^ f1 x ^ ", " ^ f2 y ^ ")";
60 fun print_list f = enclose "[" "]" o commas o map f;
62 fun print_option f NONE = "NONE"
63 | print_option f (SOME x) = "SOME (" ^ f x ^ ")";
66 if not (Symbol.is_char s) then raise Fail ("Bad character: " ^ quote s)
67 else if s = "\"" then "\\\""
68 else if s = "\\" then "\\\\"
71 if c < 32 then "\\^" ^ chr (c + ord "@")
72 else if c < 127 then s
73 else "\\" ^ string_of_int c
76 val print_string = quote o translate_string print_char;
77 val print_strings = print_list print_string;
79 val print_indexname = print_pair print_string print_int;
81 val print_class = print_string;
82 val print_sort = print_list print_class;
84 fun print_typ (Type arg) = "Type " ^ print_pair print_string (print_list print_typ) arg
85 | print_typ (TFree arg) = "TFree " ^ print_pair print_string print_sort arg
86 | print_typ (TVar arg) = "TVar " ^ print_pair print_indexname print_sort arg;
88 fun print_term (Const arg) = "Const " ^ print_pair print_string print_typ arg
89 | print_term (Free arg) = "Free " ^ print_pair print_string print_typ arg
90 | print_term (Var arg) = "Var " ^ print_pair print_indexname print_typ arg
91 | print_term (Bound i) = "Bound " ^ print_int i
92 | print_term (Abs (s, T, t)) =
93 "Abs (" ^ print_string s ^ ", " ^ print_typ T ^ ", " ^ print_term t ^ ")"
94 | print_term (t1 $ t2) = atomic (print_term t1) ^ " $ " ^ atomic (print_term t2);