ext_filename.ml

(* Copyright (C) 2015-2016 Bloomberg Finance L.P.
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * In addition to the permissions granted to you by the LGPL, you may combine
 * or link a "work that uses the Library" with a publicly distributed version
 * of this file to produce a combined library or application, then distribute
 * that combined work under the terms of your choosing, with no requirement
 * to comply with the obligations normally placed on you by section 4 of the
 * LGPL version 3 (or the corresponding section of a later version of the LGPL
 * should you choose to use a later version).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)




let is_dir_sep_unix c = c = '/'
let is_dir_sep_win_cygwin c = 
  c = '/' || c = '\\' || c = ':'

let is_dir_sep = 
  if Sys.unix then is_dir_sep_unix else is_dir_sep_win_cygwin

(* reference ninja.cc IsKnownShellSafeCharacter *)
let maybe_quote ( s : string) = 
  let noneed_quote = 
    Ext_string.for_all s (function
        | '0' .. '9' 
        | 'a' .. 'z' 
        | 'A' .. 'Z'
        | '_' | '+' 
        | '-' | '.'
        | '/' 
        | '@' -> true
        | _ -> false
      )  in 
  if noneed_quote then
    s
  else Filename.quote s 


let chop_extension_maybe name =
  let rec search_dot i =
    if i < 0 || is_dir_sep (String.unsafe_get name i) then name
    else if String.unsafe_get name i = '.' then String.sub name 0 i
    else search_dot (i - 1) in
  search_dot (String.length name - 1)

let get_extension_maybe name =   
  let name_len = String.length name in  
  let rec search_dot name i name_len =
    if i < 0 || is_dir_sep (String.unsafe_get name i) then ""
    else if String.unsafe_get name i = '.' then String.sub name i (name_len - i)
    else search_dot name (i - 1) name_len in
  search_dot name (name_len - 1) name_len

let chop_all_extensions_maybe name =
  let rec search_dot i last =
    if i < 0 || is_dir_sep (String.unsafe_get name i) then 
      (match last with 
      | None -> name
      | Some i -> String.sub name 0 i)  
    else if String.unsafe_get name i = '.' then 
      search_dot (i - 1) (Some i)
    else search_dot (i - 1) last in
  search_dot (String.length name - 1) None


let new_extension name (ext : string) = 
  let rec search_dot name i ext =
    if i < 0 || is_dir_sep (String.unsafe_get name i) then 
      name ^ ext 
    else if String.unsafe_get name i = '.' then 
      let ext_len = String.length ext in
      let buf = Bytes.create (i + ext_len) in 
      Bytes.blit_string name 0 buf 0 i;
      Bytes.blit_string ext 0 buf i ext_len;
      Bytes.unsafe_to_string buf
    else search_dot name (i - 1) ext  in
  search_dot name (String.length name - 1) ext



(** TODO: improve efficiency
   given a path, calcuate its module name 
   Note that `ocamlc.opt -c aa.xx.mli` gives `aa.xx.cmi`
   we can not strip all extensions, otherwise
   we can not tell the difference between "x.cpp.ml" 
   and "x.ml"
*)
let module_name name = 
  let rec search_dot i  name =
    if i < 0  then 
      Ext_string.capitalize_ascii name
    else 
    if String.unsafe_get name i = '.' then 
      Ext_string.capitalize_sub name i 
    else 
      search_dot (i - 1) name in  
  let name = Filename.basename  name in 
  let name_len = String.length name in 
  search_dot (name_len - 1)  name 

type module_info = {
  module_name : string ;
  case : bool;
} 



let rec valid_module_name_aux name off len =
  if off >= len then true 
  else 
    let c = String.unsafe_get name off in 
    match c with 
    | 'A'..'Z' | 'a'..'z' | '0'..'9' | '_' | '\'' -> 
      valid_module_name_aux name (off + 1) len 
    | _ -> false

type state = 
  | Invalid
  | Upper
  | Lower

let valid_module_name name len =     
  if len = 0 then Invalid
  else 
    let c = String.unsafe_get name 0 in 
    match c with 
    | 'A' .. 'Z'
      -> 
      if valid_module_name_aux name 1 len then 
        Upper
      else Invalid  
    | 'a' .. 'z' 
      -> 
      if valid_module_name_aux name 1 len then
        Lower
      else Invalid
    | _ -> Invalid


let as_module ~basename =
  let rec search_dot i  name name_len =
    if i < 0  then
      (* Input e.g, [a_b] *)
      match valid_module_name name name_len with 
      | Invalid -> None 
      | Upper ->  Some {module_name = name; case = true }
      | Lower -> Some {module_name = Ext_string.capitalize_ascii name; case = false}
    else 
    if String.unsafe_get name i = '.' then 
      (*Input e.g, [A_b] *)
      match valid_module_name  name i with 
      | Invalid -> None 
      | Upper -> 
        Some {module_name = Ext_string.capitalize_sub name i; case = true}
      | Lower -> 
        Some {module_name = Ext_string.capitalize_sub name i; case = false}
    else 
      search_dot (i - 1) name name_len in  
  let name_len = String.length basename in       
  search_dot (name_len - 1)  basename name_len