Source file nstream.ml
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module Position = struct
type t = Lexing.position = {
pos_fname : string;
pos_lnum : int;
pos_bol : int;
pos_cnum : int;
}
let to_string t =
Printf.sprintf "%s%d:%d"
(if t.pos_fname = "" then "" else t.pos_fname ^ ":")
t.pos_lnum
(t.pos_cnum - t.pos_bol)
let zero = { pos_fname = "";
pos_lnum = 1;
pos_bol = 0;
pos_cnum = 0 }
let column p = p.pos_cnum - p.pos_bol
end
module Region = struct
open Position
type t = Position.t * Position.t
let fst = fst
let snd = snd
let create p1 p2 = (p1,p2)
let start_column (p,_) = column p
let end_column (_,p) = column p
let start_line (p,_) = p.pos_lnum
let end_line (_,p) = p.pos_lnum
let char_offset (p, _) = p.pos_cnum
let length (p1, p2) = p2.Position.pos_cnum - p1.Position.pos_cnum
let zero = (Position.zero, Position.zero)
let translate (p,p') diff =
{ p with pos_cnum = p .pos_cnum + diff },
{ p' with pos_cnum = p'.pos_cnum + diff }
end
type token = {
token : Approx_lexer.token;
between : string;
substr : string;
region : Region.t;
offset : int;
}
type snapshot = Approx_lexer.context * Region.t
type cons =
| Cons of token * snapshot * t
| Null
and t = cons lazy_t
let find_first_non_space s =
let rec loop s i =
if i < String.length s then
if s.[i] <> ' ' && s.[i] <> '\t' && s.[i] <> '\012' then
i
else
loop s (succ i)
else
i in
loop s 0
let rec process st lexbuf between last =
lazy begin
match Approx_lexer.token st lexbuf with
| st, Approx_lexer.SPACES ->
assert (between = "");
Lazy.force (process st lexbuf (Lexing.lexeme lexbuf) last)
| st, token ->
let substr = Lexing.lexeme lexbuf in
let i = find_first_non_space substr in
assert (i = 0 ||
token = Approx_lexer.ESCAPED_EOL ||
token = Approx_lexer.STRING_CONTENT ||
token = Approx_lexer.STRING_CLOSE ||
token = Approx_lexer.COMMENT_CONTENT ||
token = Approx_lexer.COMMENT_CLOSE ||
token = Approx_lexer.COMMENT_VERB_CLOSE ||
token = Approx_lexer.P4_QUOTATION_CONTENT ||
token = Approx_lexer.PPX_QUOTATION_CONTENT);
let between, substr =
if i = 0 then between, substr
else (assert (between = "");
String.sub substr 0 i,
String.sub substr i (String.length substr - i)) in
let region =
Region.create lexbuf.Lexing.lex_start_p lexbuf.Lexing.lex_curr_p in
let offset = Region.start_column region - Region.start_column last in
let located_token = { token; between; substr; region; offset; } in
match token with
| Approx_lexer.EOF ->
Cons (located_token, (st, region), lazy Null)
| _ ->
Cons (located_token, (st, region), process st lexbuf "" region)
end
let of_channel ?st:((st, last) = (Approx_lexer.initial_state, Region.zero)) ic =
let lb = Lexing.from_channel ic in
lb.Lexing.lex_start_p <- Region.snd last;
lb.Lexing.lex_curr_p <- Region.snd last;
lb.Lexing.lex_abs_pos <- lb.Lexing.lex_curr_p.Lexing.pos_cnum;
process st lb "" last
let of_string ?st:((st, last) = (Approx_lexer.initial_state, Region.zero)) ic =
let lb = Lexing.from_string ic in
lb.Lexing.lex_start_p <- Region.snd last;
lb.Lexing.lex_curr_p <- Region.snd last;
lb.Lexing.lex_abs_pos <- lb.Lexing.lex_curr_p.Lexing.pos_cnum;
process st lb "" last
let display ppf tok =
Format.fprintf ppf
"STREAM (%s, %s)\n\
\ - tok: %s\n\
\ - between: %S\n\
\ - substr: %S\n\
\ - offset: %d\n%!"
(Position.to_string (Region.fst tok.region))
(Position.to_string (Region.snd tok.region))
(Approx_tokens.string_of_tok tok.token)
tok.between
tok.substr
tok.offset
let next = function
| lazy Null -> None
| lazy (Cons (tok, _, st)) -> Some (tok, st)
let next_full = function
| lazy Null -> None
| lazy (Cons (tok, snap, st)) -> Some (tok, snap, st)
module Simple = struct
type token = Approx_lexer.Simple.t = {
token: Approx_lexer.Simple.token ;
substr: string ;
region: Region.t ;
}
type stream =
| Null
| Cons of token * stream Lazy.t
type t = stream Lazy.t
let rec process st lb : stream Lazy.t = lazy begin
match Approx_lexer.Simple.token st lb with
| None -> Null
| Some ({token=Approx_lexer.Simple.EOF; _} as token, _) ->
Cons (token, lazy Null)
| Some (token, st) -> Cons (token, process st lb)
end
let of_channel ic =
let lb = Lexing.from_channel ic in
process Approx_lexer.initial_state lb
let of_string s =
let lb = Lexing.from_string s in
process Approx_lexer.initial_state lb
let next : t -> _ = function
| lazy Null -> None
| lazy (Cons (tok, stream)) -> Some (tok, stream)
end