(* Title: Pure/Syntax/lexicon.ML
ID: $Id$
Author: Tobias Nipkow and Markus Wenzel, TU Muenchen
Lexer for the inner Isabelle syntax (terms and types).
*)
signature LEXICON0 =
sig
val is_identifier: string -> bool
val is_ascii_identifier: string -> bool
val is_tid: string -> bool
val implode_xstr: string list -> string
val explode_xstr: string -> string list
val scan_id: Symbol.symbol list -> Symbol.symbol list * Symbol.symbol list
val scan_longid: Symbol.symbol list -> Symbol.symbol list * Symbol.symbol list
val scan_tid: Symbol.symbol list -> Symbol.symbol list * Symbol.symbol list
val scan_nat: Symbol.symbol list -> Symbol.symbol list * Symbol.symbol list
val scan_int: Symbol.symbol list -> Symbol.symbol list * Symbol.symbol list
val scan_hex: Symbol.symbol list -> Symbol.symbol list * Symbol.symbol list
val scan_bin: Symbol.symbol list -> Symbol.symbol list * Symbol.symbol list
val scan_var: Symbol.symbol list -> Symbol.symbol list * Symbol.symbol list
val scan_tvar: Symbol.symbol list -> Symbol.symbol list * Symbol.symbol list
val read_indexname: string -> indexname
val read_var: string -> term
val read_variable: string -> indexname option
val const: string -> term
val free: string -> term
val var: indexname -> term
val read_nat: string -> int option
val read_int: string -> int option
val read_xnum: string -> {radix: int, leading_zeros: int, value: int}
val read_idents: string -> string list
val fixedN: string
val constN: string
end;
signature LEXICON =
sig
include LEXICON0
val is_xid: string -> bool
datatype token =
Token of string |
IdentSy of string |
LongIdentSy of string |
VarSy of string |
TFreeSy of string |
TVarSy of string |
NumSy of string |
XNumSy of string |
StrSy of string |
EndToken
val idT: typ
val longidT: typ
val varT: typ
val tidT: typ
val tvarT: typ
val terminals: string list
val is_terminal: string -> bool
val str_of_token: token -> string
val display_token: token -> string
val matching_tokens: token * token -> bool
val valued_token: token -> bool
val predef_term: string -> token option
val tokenize: Scan.lexicon -> bool -> string list -> token list
end;
structure Lexicon: LEXICON =
struct
(** is_identifier etc. **)
val is_identifier = Symbol.is_ident o Symbol.explode;
fun is_ascii_identifier s =
let val cs = Symbol.explode s
in forall Symbol.is_ascii cs andalso Symbol.is_ident cs end;
fun is_xid s =
(case Symbol.explode s of
"_" :: cs => Symbol.is_ident cs
| cs => Symbol.is_ident cs);
fun is_tid s =
(case Symbol.explode s of
"'" :: cs => Symbol.is_ident cs
| _ => false);
(** basic scanners **)
val scan_id = Scan.one Symbol.is_letter ::: Scan.many Symbol.is_letdig;
val scan_longid = scan_id @@@ (Scan.repeat1 ($$ "." ::: scan_id) >> flat);
val scan_tid = $$ "'" ::: scan_id;
val scan_nat = Scan.many1 Symbol.is_digit;
val scan_int = $$ "-" ::: scan_nat || scan_nat;
val scan_hex = $$ "0" ::: $$ "x" ::: Scan.many1 Symbol.is_ascii_hex;
val scan_bin = $$ "0" ::: $$ "b" ::: Scan.many1 (fn s => s = "0" orelse s = "1");
val scan_id_nat = scan_id @@@ Scan.optional ($$ "." ::: scan_nat) [];
val scan_var = $$ "?" ::: scan_id_nat;
val scan_tvar = $$ "?" ::: $$ "'" ::: scan_id_nat;
(** datatype token **)
datatype token =
Token of string |
IdentSy of string |
LongIdentSy of string |
VarSy of string |
TFreeSy of string |
TVarSy of string |
NumSy of string |
XNumSy of string |
StrSy of string |
EndToken;
(* terminal arguments *)
val idT = Type ("id", []);
val longidT = Type ("longid", []);
val varT = Type ("var", []);
val tidT = Type ("tid", []);
val tvarT = Type ("tvar", []);
val terminals = ["id", "longid", "var", "tid", "tvar", "num", "xnum", "xstr"];
val is_terminal = member (op =) terminals;
(* str_of_token *)
fun str_of_token (Token s) = s
| str_of_token (IdentSy s) = s
| str_of_token (LongIdentSy s) = s
| str_of_token (VarSy s) = s
| str_of_token (TFreeSy s) = s
| str_of_token (TVarSy s) = s
| str_of_token (NumSy s) = s
| str_of_token (XNumSy s) = s
| str_of_token (StrSy s) = s
| str_of_token EndToken = "EOF";
(* display_token *)
fun display_token (Token s) = quote s
| display_token (IdentSy s) = "id(" ^ s ^ ")"
| display_token (LongIdentSy s) = "longid(" ^ s ^ ")"
| display_token (VarSy s) = "var(" ^ s ^ ")"
| display_token (TFreeSy s) = "tid(" ^ s ^ ")"
| display_token (TVarSy s) = "tvar(" ^ s ^ ")"
| display_token (NumSy s) = "num(" ^ s ^ ")"
| display_token (XNumSy s) = "xnum(" ^ s ^ ")"
| display_token (StrSy s) = "xstr(" ^ s ^ ")"
| display_token EndToken = "";
(* matching_tokens *)
fun matching_tokens (Token x, Token y) = (x = y)
| matching_tokens (IdentSy _, IdentSy _) = true
| matching_tokens (LongIdentSy _, LongIdentSy _) = true
| matching_tokens (VarSy _, VarSy _) = true
| matching_tokens (TFreeSy _, TFreeSy _) = true
| matching_tokens (TVarSy _, TVarSy _) = true
| matching_tokens (NumSy _, NumSy _) = true
| matching_tokens (XNumSy _, XNumSy _) = true
| matching_tokens (StrSy _, StrSy _) = true
| matching_tokens (EndToken, EndToken) = true
| matching_tokens _ = false;
(* valued_token *)
fun valued_token (Token _) = false
| valued_token (IdentSy _) = true
| valued_token (LongIdentSy _) = true
| valued_token (VarSy _) = true
| valued_token (TFreeSy _) = true
| valued_token (TVarSy _) = true
| valued_token (NumSy _) = true
| valued_token (XNumSy _) = true
| valued_token (StrSy _) = true
| valued_token EndToken = false;
(* predef_term *)
fun predef_term "id" = SOME (IdentSy "id")
| predef_term "longid" = SOME (LongIdentSy "longid")
| predef_term "var" = SOME (VarSy "var")
| predef_term "tid" = SOME (TFreeSy "tid")
| predef_term "tvar" = SOME (TVarSy "tvar")
| predef_term "num" = SOME (NumSy "num")
| predef_term "xnum" = SOME (XNumSy "xnum")
| predef_term "xstr" = SOME (StrSy "xstr")
| predef_term _ = NONE;
(* xstr tokens *)
fun lex_err msg prfx (cs, _) =
"Inner lexical error: " ^ msg ^ " at " ^ quote (prfx ^ Symbol.beginning 10 cs);
val scan_chr =
$$ "\\" |-- $$ "'" ||
Scan.one (fn s => s <> "\\" andalso s <> "'" andalso Symbol.is_regular s) ||
$$ "'" --| Scan.ahead (~$$ "'");
val scan_str =
$$ "'" |-- $$ "'" |-- !! (lex_err "missing end of string" "''")
(Scan.repeat scan_chr --| $$ "'" --| $$ "'");
fun implode_xstr cs = enclose "''" "''" (implode (map (fn "'" => "\\'" | c => c) cs));
fun explode_xstr str =
(case Scan.read Symbol.stopper scan_str (Symbol.explode str) of
SOME cs => cs
| _ => error ("Inner lexical error: literal string expected at " ^ quote str));
(* nested comments *)
val scan_cmt =
Scan.depend (fn d => $$ "(" ^^ $$ "*" >> pair (d + 1)) ||
Scan.depend (fn 0 => Scan.fail | d => $$ "*" ^^ $$ ")" >> pair (d - 1)) ||
Scan.lift ($$ "*" --| Scan.ahead (~$$ ")")) ||
Scan.lift (Scan.one (fn s => s <> "*" andalso Symbol.is_regular s));
val scan_comment =
$$ "(" -- $$ "*" -- !! (lex_err "missing end of comment" "(*")
(Scan.pass 0 (Scan.repeat scan_cmt) -- $$ "*" -- $$ ")")
>> K ();
(** tokenize **)
fun tokenize lex xids chs =
let
fun token kind cs = (kind, implode cs);
val scan_xid =
if xids then $$ "_" ::: scan_id || scan_id
else scan_id;
val scan_num = scan_hex || scan_bin || scan_int;
val scan_val =
scan_tvar >> token TVarSy ||
scan_var >> token VarSy ||
scan_tid >> token TFreeSy ||
scan_num >> token NumSy ||
$$ "#" ::: scan_num >> token XNumSy ||
scan_longid >> token LongIdentSy ||
scan_xid >> token IdentSy;
val scan_lit = Scan.literal lex >> token Token;
val scan_token =
scan_comment >> K NONE ||
Scan.max (op <= o pairself snd) scan_lit scan_val >> (fn (tk, s) => SOME (tk s)) ||
scan_str >> (SOME o StrSy o implode_xstr) ||
Scan.one Symbol.is_blank >> K NONE;
in
(case Scan.error (Scan.finite Symbol.stopper (Scan.repeat scan_token)) chs of
(toks, []) => map_filter I toks
| (_, cs) => error ("Inner lexical error at: " ^ quote (implode cs)))
end;
(** scan variables **)
(* scan_indexname *)
local
fun scan_vname chrs =
let
fun nat n [] = n
| nat n (c :: cs) = nat (n * 10 + (ord c - ord "0")) cs;
fun idxname cs ds = (implode (rev cs), nat 0 ds);
fun chop_idx [] ds = idxname [] ds
| chop_idx (cs as (_ :: "\\<^isub>" :: _)) ds = idxname cs ds
| chop_idx (cs as (_ :: "\\<^isup>" :: _)) ds = idxname cs ds
| chop_idx (c :: cs) ds =
if Symbol.is_digit c then chop_idx cs (c :: ds)
else idxname (c :: cs) ds;
val scan = scan_id -- Scan.optional ($$ "." |-- scan_nat >> nat 0) ~1;
in
(case scan chrs of
((cs, ~1), cs') => (chop_idx (rev cs) [], cs')
| ((cs, i), cs') => ((implode cs, i), cs'))
end;
in
val scan_indexname =
$$ "'" |-- scan_vname >> (fn (x, i) => ("'" ^ x, i))
|| scan_vname;
end;
(* indexname *)
fun read_indexname s =
(case Scan.read Symbol.stopper scan_indexname (Symbol.explode s) of
SOME xi => xi
| _ => error ("Lexical error in variable name: " ^ quote s));
(* read_var *)
fun const c = Const (c, dummyT);
fun free x = Free (x, dummyT);
fun var xi = Var (xi, dummyT);
fun read_var str =
let
val scan =
$$ "?" |-- scan_indexname --| Scan.ahead (Scan.one Symbol.is_eof) >> var ||
Scan.many Symbol.is_regular >> (free o implode);
in the (Scan.read Symbol.stopper scan (Symbol.explode str)) end;
(* read_variable *)
fun read_variable str =
let val scan = $$ "?" |-- scan_indexname || scan_indexname
in Scan.read Symbol.stopper scan (Symbol.explode str) end;
(* specific identifiers *)
val constN = "\\<^const>";
val fixedN = "\\<^fixed>";
(* read numbers *)
local
fun nat cs =
Option.map (#1 o Library.read_int)
(Scan.read Symbol.stopper scan_nat cs);
in
val read_nat = nat o Symbol.explode;
fun read_int s =
(case Symbol.explode s of
"-" :: cs => Option.map ~ (nat cs)
| cs => nat cs);
end;
(* read_xnum: hex/bin/decimal *)
local
val ten = ord "0" + 10;
val a = ord "a";
val A = ord "A";
val _ = a > A orelse sys_error "Bad ASCII";
fun remap_hex c =
let val x = ord c in
if x >= a then chr (x - a + ten)
else if x >= A then chr (x - A + ten)
else c
end;
fun leading_zeros ["0"] = 0
| leading_zeros ("0" :: cs) = 1 + leading_zeros cs
| leading_zeros _ = 0;
in
fun read_xnum str =
let
val (sign, radix, digs) =
(case Symbol.explode (perhaps (try (unprefix "#")) str) of
"0" :: "x" :: cs => (1, 16, map remap_hex cs)
| "0" :: "b" :: cs => (1, 2, cs)
| "-" :: cs => (~1, 10, cs)
| cs => (1, 10, cs));
val value = sign * #1 (Library.read_radix_int radix digs);
in {radix = radix, leading_zeros = leading_zeros digs, value = value} end;
end;
(* read_ident(s) *)
fun read_idents str =
let
val blanks = Scan.many Symbol.is_blank;
val junk = Scan.many Symbol.is_regular;
val idents = Scan.repeat1 (blanks |-- (scan_id >> implode) --| blanks) -- junk;
in
(case Scan.read Symbol.stopper idents (Symbol.explode str) of
SOME (ids, []) => ids
| SOME (_, bad) => error ("Bad identifier: " ^ quote (implode bad))
| NONE => error ("No identifier found in: " ^ quote str))
end;
end;