Implement simple pretty-printing library and basic tabs view

dune-project

@@ -23,6 +23,7 @@
    (cmdliner (>= "1.2.0"))
    (ezcurl (>= "0.2.4"))
    (minttea (>= "0.0.2"))
+   uuseg.string
  )
  (tags
   (tui cli git github)))

github_tui.opam

@@ -15,7 +15,7 @@ depends: [
   "cmdliner" {>= "1.2.0"}
   "ezcurl" {>= "0.2.4"}
   "minttea" {>= "0.0.2"}
-  "spices"
+  "uuseg.string"
   "odoc" {with-doc}
 ]
 build: [

lib/dune

@@ -7,5 +7,6 @@
    cmdliner
    ezcurl
    minttea
+   uuseg.string
  )
 )

lib/pretty.ml

@@ -0,0 +1,45 @@
+(* A simple pretty printing combinator library *)
+
+type doc =
+  | Empty
+  | Str of string
+  | Vertical of doc * doc
+  | Horizontal of doc * doc
+
+let (---) t b = Vertical (t, b)
+let (<|>) l r = Horizontal (l, r)
+
+let graphemes_len = 
+  Uuseg_string.fold_utf_8 `Grapheme_cluster (fun len _ -> len + 1) 0
+
+let fill_right (n : int) (s : string) : string =
+  s ^ String.concat "" (List.init (n - graphemes_len s) (fun _ -> ""))
+
+let zip_lines l r =
+  let max_len_l = List.map graphemes_len l |> List.fold_left max 0 in
+  let padding = String.make max_len_l ' ' in
+  let rec zip l r =
+    match (l, r) with
+    | (l, []) -> 
+      l
+    | ([], r) -> 
+      List.map (fun s -> padding ^ s) r
+    | (hd_l :: tl_l, hd_r :: tl_r) ->
+      (fill_right max_len_l hd_l ^ hd_r) :: zip tl_l tl_r
+  in
+  zip l r
+
+let rec render_to_lines = function
+  | Empty ->
+    []
+  | Str s ->
+    [s]
+  | Vertical (top, bottom) ->
+    render_to_lines top @ render_to_lines bottom
+  | Horizontal (left, right) ->
+    zip_lines (render_to_lines left) (render_to_lines right)
+
+let render doc = 
+  doc
+  |> render_to_lines
+  |> String.concat "\n"

lib/tui/view.ml

@@ -2,19 +2,47 @@ let fmt (styles : ANSITerminal.style list) : string -> string =
   ANSITerminal.sprintf styles "%s"
 
 let fmt_repo =
+  fmt ANSITerminal.([Bold; blue])
+
+let fmt_selected_tab =
   fmt ANSITerminal.([Bold; green])
 
+let tab_section cur_tab =
+  let p_tab tab txt = 
+    if cur_tab = tab
+    then Pretty.Str (fmt_selected_tab txt)
+    else Pretty.Str txt
+  in
+  Pretty.(render (
+      (p_tab Model.Code "╭──────╮" ---
+       p_tab Model.Code "│ Code │" ---
+       p_tab Model.Code "└──────┴"
+      ) <|>
+      (Str " " ---
+       Str " " ---
+       Str "─"
+      ) <|>
+      (p_tab Model.Issues "╭────────╮" ---
+       p_tab Model.Issues "│ Issues │" ---
+       p_tab Model.Issues "┴────────┴"
+      ) <|>
+      (Str " " ---
+       Str " " ---
+       Str "─"
+      ) <|>
+      (p_tab Model.PullRequests "╭───────────────╮" ---
+       p_tab Model.PullRequests "│ Pull Requests │" ---
+       p_tab Model.PullRequests "┴───────────────┴"
+      )
+    )
+  )
+
 let view (model: Model.t) =
   let repo = fmt_repo model.repo in
-  let tab = 
-    match model.tab with
-    | Code -> "Code"
-    | Issues -> "Issues"
-    | PullRequests -> "Pull Requests" 
-  in
+  let tabs = tab_section model.tab in
   Format.sprintf 
 {|%s
 
 %s
 
-|} repo tab
+|} repo tabs