author | haftmann |
Sat, 15 Sep 2007 19:27:35 +0200 | |
changeset 24584 | 01e83ffa6c54 |
parent 23784 | 75e6b9dd5336 |
child 26537 | 188961eb1f08 |
permissions | -rw-r--r-- |
24584 | 1 |
(* Title: HOL/Import/xml.ML |
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ID: $Id$ |
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Author: David Aspinall, Stefan Berghofer and Markus Wenzel |
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Basic support for XML. |
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*) |
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signature XML = |
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sig |
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val header: string |
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val text: string -> string |
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val text_charref: string -> string |
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val cdata: string -> string |
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val element: string -> (string * string) list -> string list -> string |
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datatype tree = |
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Elem of string * (string * string) list * tree list |
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| Text of string |
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val string_of_tree: tree -> string |
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val tree_of_string: string -> tree |
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val encoded_string_of_tree : tree -> string |
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val tree_of_encoded_string : string -> tree |
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end; |
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structure XML :> XML = |
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struct |
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(*structure Seq = VectorScannerSeq |
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structure Scan = Scanner (structure Seq = Seq)*) |
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structure Seq = StringScannerSeq |
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structure Scan = StringScanner |
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open Scan |
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(** string based representation (small scale) **) |
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val header = "<?xml version=\"1.0\"?>\n"; |
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(* text and character data *) |
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fun decode "<" = "<" |
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| decode ">" = ">" |
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| decode "&" = "&" |
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| decode "'" = "'" |
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| decode """ = "\"" |
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| decode c = c; |
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fun encode "<" = "<" |
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| encode ">" = ">" |
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| encode "&" = "&" |
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| encode "'" = "'" |
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| encode "\"" = """ |
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| encode c = c; |
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fun encode_charref c = "&#" ^ Int.toString (ord c) ^ ";" |
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val text = Library.translate_string encode |
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val text_charref = translate_string encode_charref; |
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val cdata = enclose "<![CDATA[" "]]>\n" |
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(* elements *) |
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fun attribute (a, x) = a ^ " = \"" ^ text x ^ "\""; |
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fun element name atts cs = |
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let val elem = space_implode " " (name :: map attribute atts) in |
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if null cs then enclose "<" "/>" elem |
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else enclose "<" ">" elem ^ implode cs ^ enclose "</" ">" name |
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end; |
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(** explicit XML trees **) |
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datatype tree = |
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Elem of string * (string * string) list * tree list |
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| Text of string; |
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fun string_of_tree tree = |
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let |
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fun string_of (Elem (name, atts, ts)) buf = |
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let val buf' = |
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buf |> Buffer.add "<" |
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|> fold Buffer.add (separate " " (name :: map attribute atts)) |
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in |
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if null ts then |
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buf' |> Buffer.add "/>" |
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else |
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buf' |> Buffer.add ">" |
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|> fold string_of ts |
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|> Buffer.add "</" |> Buffer.add name |> Buffer.add ">" |
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end |
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| string_of (Text s) buf = Buffer.add (text s) buf; |
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in Buffer.content (string_of tree Buffer.empty) end; |
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(** XML parsing **) |
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fun beginning n xs = Symbol.beginning n (Seq.take_at_most xs n) |
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fun err s xs = |
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"XML parsing error: " ^ s ^ "\nfound: " ^ quote (beginning 100 xs) ; |
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val scan_whspc = Scan.any Symbol.is_blank; |
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val scan_special = $$ "&" ^^ scan_id ^^ $$ ";" >> decode; |
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val parse_chars = Scan.repeat1 (Scan.unless ((* scan_whspc -- *)$$ "<") |
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23784
75e6b9dd5336
Symbol.not_eof/sync is superceded by Symbol.is_regular (rules out further control symbols);
wenzelm
parents:
19095
diff
changeset
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(scan_special || Scan.one Symbol.is_regular)) >> implode; |
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val parse_cdata = Scan.this_string "<![CDATA[" |-- |
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23784
75e6b9dd5336
Symbol.not_eof/sync is superceded by Symbol.is_regular (rules out further control symbols);
wenzelm
parents:
19095
diff
changeset
|
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(Scan.repeat (Scan.unless (Scan.this_string "]]>") (Scan.one Symbol.is_regular)) >> |
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implode) --| Scan.this_string "]]>"; |
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val parse_att = |
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scan_id --| scan_whspc --| $$ "=" --| scan_whspc -- |
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(($$ "\"" || $$ "'") :-- (fn s => (Scan.repeat (Scan.unless ($$ s) |
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23784
75e6b9dd5336
Symbol.not_eof/sync is superceded by Symbol.is_regular (rules out further control symbols);
wenzelm
parents:
19095
diff
changeset
|
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(scan_special || Scan.one Symbol.is_regular)) >> implode) --| $$ s) >> snd); |
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val parse_comment = Scan.this_string "<!--" -- |
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23784
75e6b9dd5336
Symbol.not_eof/sync is superceded by Symbol.is_regular (rules out further control symbols);
wenzelm
parents:
19095
diff
changeset
|
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Scan.repeat (Scan.unless (Scan.this_string "-->") (Scan.one Symbol.is_regular)) -- |
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Scan.this_string "-->"; |
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val scan_comment_whspc = |
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(scan_whspc >> K()) --| (Scan.repeat (parse_comment |-- (scan_whspc >> K()))); |
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val parse_pi = Scan.this_string "<?" |-- |
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23784
75e6b9dd5336
Symbol.not_eof/sync is superceded by Symbol.is_regular (rules out further control symbols);
wenzelm
parents:
19095
diff
changeset
|
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Scan.repeat (Scan.unless (Scan.this_string "?>") (Scan.one Symbol.is_regular)) --| |
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Scan.this_string "?>"; |
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fun parse_content xs = |
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((Scan.optional ((* scan_whspc |-- *) parse_chars >> (single o Text)) [] -- |
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(Scan.repeat ((* scan_whspc |-- *) |
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( parse_elem >> single |
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|| parse_cdata >> (single o Text) |
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|| parse_pi >> K [] |
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|| parse_comment >> K []) -- |
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Scan.optional ((* scan_whspc |-- *) parse_chars >> (single o Text)) [] |
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>> op @) >> List.concat) >> op @)(* --| scan_whspc*)) xs |
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and parse_elem xs = |
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($$ "<" |-- scan_id -- |
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Scan.repeat (scan_whspc |-- parse_att) --| scan_whspc :-- (fn (s, _) => |
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!! (err "Expected > or />") |
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(Scan.this_string "/>" >> K [] |
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|| $$ ">" |-- parse_content --| |
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!! (err ("Expected </" ^ s ^ ">")) |
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(Scan.this_string ("</" ^ s) --| scan_whspc --| $$ ">"))) >> |
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(fn ((s, atts), ts) => Elem (s, atts, ts))) xs; |
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val parse_document = |
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Scan.option (Scan.this_string "<!DOCTYPE" -- scan_whspc |-- |
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(Scan.repeat (Scan.unless ($$ ">") |
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23784
75e6b9dd5336
Symbol.not_eof/sync is superceded by Symbol.is_regular (rules out further control symbols);
wenzelm
parents:
19095
diff
changeset
|
156 |
(Scan.one Symbol.is_regular)) >> implode) --| $$ ">" --| scan_whspc) -- |
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parse_elem; |
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fun tree_of_string s = |
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let |
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val seq = Seq.fromString s |
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val scanner = !! (err "Malformed element") (scan_whspc |-- parse_elem --| scan_whspc) |
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val (x, toks) = scanner seq |
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in |
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if Seq.null toks then x else error ("Unprocessed input: '"^(beginning 100 toks)^"'") |
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end |
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(* More efficient saving and loading of xml trees employing a proprietary external format *) |
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fun write_lstring s buf = buf |> Buffer.add (string_of_int (size s)) |> Buffer.add " " |> Buffer.add s |
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fun parse_lstring toks = (scan_nat --| one Symbol.is_blank :-- (fn i => repeat_fixed i (one (K true))) >> snd >> implode) toks |
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fun write_list w l buf = buf |> Buffer.add (string_of_int (length l)) |> Buffer.add " " |> fold w l |
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fun parse_list sc = scan_nat --| one Symbol.is_blank :-- (fn i => repeat_fixed i sc) >> snd |
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fun write_tree (Text s) buf = buf |> Buffer.add "T" |> write_lstring s |
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| write_tree (Elem (name, attrs, children)) buf = |
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buf |> Buffer.add "E" |
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|> write_lstring name |
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|> write_list (fn (a,b) => fn buf => buf |> write_lstring a |> write_lstring b) attrs |
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|> write_list write_tree children |
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fun parse_tree toks = (one (K true) :-- (fn "T" => parse_lstring >> Text | "E" => parse_elem | _ => raise SyntaxError) >> snd) toks |
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and parse_elem toks = (parse_lstring -- parse_list (parse_lstring -- parse_lstring) -- parse_list parse_tree >> (fn ((n, a), c) => Elem (n,a,c))) toks |
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fun encoded_string_of_tree tree = Buffer.content (write_tree tree Buffer.empty) |
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fun tree_of_encoded_string s = |
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let |
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fun print (a,b) = writeln (a^" "^(string_of_int b)) |
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val _ = print ("length of encoded string: ", size s) |
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val _ = writeln "Seq.fromString..." |
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val seq = timeit (fn () => Seq.fromString s) |
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val _ = print ("length of sequence", timeit (fn () => Seq.length seq)) |
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val scanner = !! (err "Malformed encoded xml") parse_tree |
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val (x, toks) = scanner seq |
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in |
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if Seq.null toks then x else error ("Unprocessed input: '"^(beginning 100 toks)^"'") |
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end |
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end; |