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scanf support for %h and %H (hex floats). 

(Contributed by Benoit Vaugon.)


git-svn-id: http://caml.inria.fr/svn/ocaml/branches/hex-float@16295 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
master
Xavier Leroy 2015-07-29 11:56:14 +00:00
parent bb86f5b545
commit 86d29bf2a6
1 changed files with 63 additions and 3 deletions
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66
stdlib/scanf.ml
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@ -442,6 +442,10 @@ let bad_float () =
bad_input "no dot or exponent part found in float token"
;;
let bad_hex_float () =
bad_input "not a valid float in hexadecimal notation"
;;
let character_mismatch_err c ci =
Printf.sprintf "looking for %C, found %C" c ci
;;
@ -769,6 +773,63 @@ let scan_caml_float width precision ib =
scan_exp_part width ib
| _ -> bad_float ()
let check_case_insensitive_string width ib error str =
let lowercase c = match c with
| 'A' .. 'Z' -> char_of_int (int_of_char c - int_of_char 'A' + int_of_char 'a')
| _ -> c in
let len = String.length str in
let width = ref width in
for i = 0 to len - 1 do
let c = Scanning.peek_char ib in
if lowercase c <> lowercase str.[i] then error ();
if !width = 0 then error ();
width := Scanning.store_char !width ib c;
done;
!width
let scan_hex_float width precision ib =
if width = 0 || Scanning.end_of_input ib then bad_hex_float ();
let width = scan_sign width ib in
if width = 0 || Scanning.end_of_input ib then bad_hex_float ();
match Scanning.peek_char ib with
| '0' as c -> (
let width = Scanning.store_char width ib c in
if width = 0 || Scanning.end_of_input ib then bad_hex_float ();
let width = check_case_insensitive_string width ib bad_hex_float "x" in
if width = 0 || Scanning.end_of_input ib then width else
let width = match Scanning.peek_char ib with
| '.' | 'p' | 'P' -> width
| _ -> scan_hexadecimal_int width ib in
if width = 0 || Scanning.end_of_input ib then width else
let width = match Scanning.peek_char ib with
| '.' as c -> (
let width = Scanning.store_char width ib c in
if width = 0 || Scanning.end_of_input ib then width else
match Scanning.peek_char ib with
| 'p' | 'P' -> width
| _ ->
let precision = min width precision in
width - (precision - scan_hexadecimal_int precision ib)
)
| _ -> width in
if width = 0 || Scanning.end_of_input ib then width else
match Scanning.peek_char ib with
| 'p' | 'P' as c ->
let width = Scanning.store_char width ib c in
if width = 0 then bad_hex_float ();
scan_optionally_signed_decimal_int width ib
| _ -> width
)
| 'n' | 'N' as c ->
let width = Scanning.store_char width ib c in
if width = 0 || Scanning.end_of_input ib then bad_hex_float ();
check_case_insensitive_string width ib bad_hex_float "an"
| 'i' | 'I' as c ->
let width = Scanning.store_char width ib c in
if width = 0 || Scanning.end_of_input ib then bad_hex_float ();
check_case_insensitive_string width ib bad_hex_float "nfinity"
| _ -> bad_hex_float ()
(* Scan a regular string:
stops when encountering a space, if no scanning indication has been given;
otherwise, stops when encountering the characters in the scanning
@ -1164,9 +1225,8 @@ fun ib fmt readers -> match fmt with
| Float_G | Float_pG | Float_sG), pad, prec, rest) ->
pad_prec_scanf ib rest readers pad prec scan_float token_float
| Float ((Float_h | Float_ph | Float_sh | Float_H | Float_pH | Float_sH),
_pad, _prec, _rest) ->
assert false (* TODO *)
pad, prec, rest) ->
pad_prec_scanf ib rest readers pad prec scan_hex_float token_float
| Bool rest ->
let _ = scan_bool ib in
let b = token_bool ib in