Extend stdlib for configurator

src/io.ml

@@ -37,15 +37,24 @@ let input_lines =
   in
   fun ic -> loop ic []
 
-let read_file fn =
-  with_file_in fn ~f:(fun ic ->
-    let len = in_channel_length ic in
-    really_input_string ic len)
+let read_all ic =
+  let len = in_channel_length ic in
+  really_input_string ic len
+
+let read_file fn = with_file_in fn ~f:read_all
 
 let lines_of_file fn = with_file_in fn ~f:input_lines ~binary:false
 
 let write_file fn data = with_file_out fn ~f:(fun oc -> output_string oc data)
 
+let write_lines fn lines =
+  with_file_out fn ~f:(fun oc ->
+    List.iter ~f:(fun line ->
+      output_string oc line;
+      output_string oc "\n"
+    ) lines
+  )
+
 let copy_channels =
   let buf_len = 65536 in
   let buf = Bytes.create buf_len in

src/io.mli

@@ -20,6 +20,10 @@ val write_file : string -> string -> unit
 
 val compare_files : string -> string -> Ordering.t
 
+val write_lines : string -> string list -> unit
+
 val copy_channels : in_channel -> out_channel -> unit
 
 val copy_file : src:string -> dst:string -> unit
+
+val read_all : in_channel -> string

src/stdune/string.ml

@@ -22,6 +22,8 @@ let break s ~pos =
   (sub s ~pos:0 ~len:pos,
    sub s ~pos ~len:(length s - pos))
 
+let is_empty s = length s = 0
+
 let is_prefix s ~prefix =
   let len = length s in
   let prefix_len = length prefix in
@@ -79,6 +81,11 @@ let lsplit2 s ~on =
       (sub s ~pos:0 ~len:i,
        sub s ~pos:(i + 1) ~len:(length s - i - 1))
 
+let lsplit2_exn s ~on =
+  match lsplit2 s ~on with
+  | Some s -> s
+  | None -> invalid_arg "lsplit2_exn"
+
 let rsplit2 s ~on =
   match rindex s on with
   | exception Not_found -> None
@@ -153,3 +160,12 @@ let longest_map l ~f =
     max acc (length (f x)))
 
 let longest l = longest_map l ~f:(fun x -> x)
+
+let exists s ~f =
+  try
+    for i=0 to length s - 1 do
+      if (f s.[i]) then raise_notrace Exit
+    done;
+    false
+  with Exit ->
+    true

src/stdune/string.mli

@@ -4,6 +4,7 @@ val compare : t -> t -> Ordering.t
 
 val break : t -> pos:int -> t * t
 
+val is_empty : t -> bool
 val is_prefix : t -> prefix:t -> bool
 val is_suffix : t -> suffix:t -> bool
 
@@ -22,6 +23,7 @@ val extract_comma_space_separated_words : t -> t list
 val extract_blank_separated_words : t -> t list
 
 val lsplit2 : t -> on:char -> (t * t) option
+val lsplit2_exn : t -> on:char -> t * t
 val rsplit2 : t -> on:char -> (t * t) option
 
 val split : t -> on:char -> t list
@@ -35,3 +37,5 @@ val escape_double_quote : t -> t
 (** Return the length of the longest string in the list *)
 val longest : string list -> int
 val longest_map : 'a list -> f:('a -> string) -> int
+
+val exists : t -> f:(char -> bool) -> bool