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jsMinify.ml
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jsMinify.ml
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(*-
* Copyright (c) 2007 Eugene Ossintsev
* Copyright (c) 2002 Douglas Crockford
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*)
exception Failure' = Failure
open Stream
let is_unsquashable a b =
match a, b with
| '+', '+' -> true
| '-', '-' -> true
| _ -> false
let is_alphanum = function
| 'a'..'z' | 'A'..'Z' | '0'..'9' | '_' | '$' | '\\' -> true
| c when ((Char.code c) > 126) -> true
| _ -> false
let is_pre_lf = function
| c when is_alphanum c -> true
| '}' | ']' | ')' | '+' | '-' | '\"' | '\'' | '.' -> true
| _ -> false
let is_post_lf = function
| c when is_alphanum c -> true
| '{' | '[' | '(' | '+' | '-' -> true
| _ -> false
let is_space = function
| '\r' | '\n' -> false
| c when ((Char.code c) <= (Char.code ' ')) -> true
| _ -> false
let is_pre_regexp = function
| '(' | ',' | '='| ':' | '['| '!'| '&' | '|' | '?' | '{' | '}' | ';' | '\n' -> true
| _ -> false
let minify str =
let s = of_string str in
let buff = Buffer.create (String.length str) in
let prev_ch = ref '\000' in
let print_ch c =
if not (is_space c) then prev_ch := c;
Buffer.add_char buff c
in
let rec next_ch () =
match peek s with
| Some '/' -> junk s; maybe_comment_or_regexp ()
| Some ('\'' as c) | Some ('\"' as c) -> junk s; print_ch c; quote c
| Some '\r' | Some '\n' -> junk s; squeeze_linefeeds ()
| Some c when is_space c -> junk s; squeeze_spaces ()
| Some c -> junk s; print_ch c; next_ch ()
| None -> ()
and squeeze_spaces () =
match peek s with
| Some c when is_space c -> junk s; squeeze_spaces ()
| Some c ->
if (is_unsquashable !prev_ch c) || ((is_alphanum !prev_ch) && (is_alphanum c))
then print_ch ' ';
next_ch ()
| None -> ()
and squeeze_linefeeds () =
match peek s with
| Some c when c = '\r' || c = '\n' || (is_space c) -> junk s; squeeze_linefeeds ()
| Some c -> if (is_pre_lf !prev_ch) && (is_post_lf c) then print_ch '\n'; next_ch ()
| None -> ()
and maybe_comment_or_regexp () =
match peek s with
| Some '/' -> junk s; line_comment ()
| Some '*' -> junk s; block_comment ()
| Some _ when is_pre_regexp !prev_ch -> print_ch '/'; quote '/'
| _ -> print_ch '/'; next_ch ()
and line_comment () =
match peek s with
| Some '\r' | Some '\n' -> junk s; squeeze_linefeeds ()
| Some _ -> junk s; line_comment ()
| None -> ()
and block_comment () =
match peek s with
| Some '*' -> junk s; maybe_block_comment_end ()
| Some _ -> junk s; block_comment ()
| None -> failwith "Unterminated comment"
and maybe_block_comment_end () =
match peek s with
| Some '/' -> junk s; squeeze_spaces ()
| Some '*' -> junk s; maybe_block_comment_end ()
| _ -> junk s; block_comment ()
and quote c =
match peek s with
| Some '\\' ->
junk s; print_ch '\\';
begin match peek s with
| Some c2 -> junk s; print_ch c2; quote c
| None -> quote c
end
| Some c2 when c2 = c -> junk s; print_ch c; next_ch ()
| Some '\r' | Some '\n' | None ->
let str = Buffer.contents buff in
let i = max 0 ((String.length str)-10) in
Printf.printf "Minify error: %s\n" (String.sub str i (min (i+100) (String.length str)));
failwith ("Unterminated " ^ (if c = '/' then "regular expression" else "string"))
| Some c2 -> junk s; print_ch c2; quote c
in
try
next_ch ();
Buffer.contents buff
with _ -> str