basic filter, sort, emit

lib/emitter.ml

@@ -0,0 +1,59 @@
+open Types
+
+type serialiser = { buf : string ref; sz : int; pos : int ref }
+
+let write_ansi a =
+  let rec intersperse sep ls =
+    match ls with
+    | [] | [ _ ] -> ls
+    | hd :: tl -> hd :: sep :: intersperse sep tl
+  and string_of_colour ?(bg = false) c =
+    let prefix = if bg then "4" else "3" and si = string_of_int in
+    c |> function
+    | Intrinsic i -> prefix ^ si i
+    | Simple i -> prefix ^ "8;5;" ^ si i
+    | RGB (r, g, b) -> prefix ^ "8;2;" ^ si r ^ ";" ^ si g ^ ";" ^ si b
+  in
+  let ansi =
+    a
+    |> List.map (fun a ->
+           match a with
+           | Fg c -> string_of_colour c
+           | Bg c -> string_of_colour ~bg:true c
+           | Reset -> "0"
+           | Other i -> string_of_int i)
+    |> intersperse ";"
+    |> List.fold_left (fun acc el -> acc ^ el) ""
+  in
+  "\x1b[" ^ ansi ^ "m"
+
+let flush t =
+  if t.pos.contents > 0 then (
+    print_string (String.sub t.buf.contents 0 t.pos.contents);
+    t.pos.contents <- 0)
+
+let serialise t chunk =
+  let input =
+    match chunk with
+    | Text s -> s
+    | Separator s -> s
+    | Delimiter s -> s
+    | Ansi a -> write_ansi a
+  in
+  let input_sz = String.length input in
+  if t.pos.contents + input_sz > t.sz then flush t;
+  if input_sz > t.sz then print_string input
+  else
+    t.buf.contents <-
+      (if t.pos.contents > 0 then String.sub t.buf.contents 0 t.pos.contents
+       else "")
+      ^ input;
+  t.pos.contents <- t.pos.contents + input_sz
+
+let create = { buf = ref String.empty; sz = 4096; pos = ref 0 }
+
+let print_debug t =
+  print_endline
+    ("pos is "
+    ^ string_of_int t.pos.contents
+    ^ "\nsz is " ^ string_of_int t.sz ^ "\ncontents are: " ^ t.buf.contents)