Fixes #39: more compact output for html and markdown

README.md

@@ -259,7 +259,7 @@ an alternative solution where trees are printed in HTML using the
 # print_endline PrintBox_html.(to_string
   ~config:Config.(tree_summary true default)
     B.(tree (text "0")[text "1"; tree (text "ω") [text "ω²"]]));;
-<div><details><summary><span class="">0</span></summary><ul><li><div class="">1</div></li><li><details><summary><span class="">ω</span></summary><ul><li><div class="">ω²</div></li></ul></details></li></ul></details></div>
+<div><details><summary><span>0</span></summary><ul><li><div>1</div></li><li><details><summary><span>ω</span></summary><ul><li><div>ω²</div></li></ul></details></li></ul></details></div>
 
 - : unit = ()
 ```

src/PrintBox.ml

@@ -65,7 +65,7 @@ let[@inline] view (t : t) : view = t
 let[@inline] line_ s = Text { l = [ s ]; style = Style.default }
 
 let line_with_style style s =
-  if String.contains s '\n' then invalid_arg "PrintBox.line";
+  if String.contains s '\n' then invalid_arg @@ "PrintBox.line: " ^ s;
   Text { l = [ s ]; style }
 
 let line s = line_with_style Style.default s

src/printbox-html/PrintBox_html.ml

@@ -62,6 +62,12 @@ let attrs_of_style (s : B.Style.t) : _ list * _ =
   in
   a, bold
 
+let a_class l =
+  if List.exists (fun s -> s <> "") l then
+    [ H.a_class l ]
+  else
+    []
+
 module Config = struct
   type t = {
     cls_table: string list;
@@ -116,7 +122,7 @@ let to_html_rec ~config (b : B.t) =
       else
         []
     in
-    H.span ~a:((H.a_class config.cls_text :: a_border) @ a @ config.a_text) l
+    H.span ~a:(a_class config.cls_text @ a_border @ a @ config.a_text) l
   in
   let v_text_to_html ?(border = false) ~l ~style () =
     let a, bold = attrs_of_style style in
@@ -128,7 +134,7 @@ let to_html_rec ~config (b : B.t) =
     in
     if style.B.Style.preformatted then
       H.pre
-        ~a:((H.a_class config.cls_text :: a_border) @ a @ config.a_text)
+        ~a:(a_class config.cls_text @ a_border @ a @ config.a_text)
         [ H.txt @@ String.concat "\n" l ]
     else (
       (* TODO: remove possible trailing '\r' *)
@@ -151,7 +157,7 @@ let to_html_rec ~config (b : B.t) =
                  []))
              l
       in
-      H.div ~a:((H.a_class config.cls_text :: a_border) @ a @ config.a_text) l
+      H.div ~a:(a_class config.cls_text @ a_border @ a @ config.a_text) l
     )
   in
   let loop
@@ -164,7 +170,8 @@ let to_html_rec ~config (b : B.t) =
     match B.view b with
     | B.Empty ->
       (H.div [] :> [< Html_types.flow5 > `Pre `Span `Div `P `Table `Ul ] html)
-    (* | B.Text {l; style} when style.B.Style.preformatted -> H.pre [h_text_to_html ~l ~style ()] *)
+    | B.Text { l; style } when style.B.Style.preformatted ->
+      H.pre [ h_text_to_html ~l ~style () ]
     | B.Text { l; style } -> v_text_to_html ~l ~style ()
     | B.Pad (_, b) -> fix b
     | B.Frame b -> H.div ~a:[ H.a_style "border:thin solid" ] [ fix b ]
@@ -182,11 +189,11 @@ let to_html_rec ~config (b : B.t) =
       let to_row a =
         Array.to_list a
         |> List.map (fun b ->
-               H.td ~a:(H.a_class config.cls_col :: config.a_col) [ fix b ])
-        |> fun x -> H.tr ~a:(H.a_class config.cls_row :: config.a_row) x
+               H.td ~a:(a_class config.cls_col @ config.a_col) [ fix b ])
+        |> fun x -> H.tr ~a:(a_class config.cls_row @ config.a_row) x
       in
       let rows = Array.to_list a |> List.map to_row in
-      H.table ~a:(H.a_class (class_ :: config.cls_table) :: config.a_table) rows
+      H.table ~a:(a_class (class_ :: config.cls_table) @ config.a_table) rows
     | B.Tree (_, b, l) ->
       let l = Array.to_list l in
       H.div [ fix b; H.ul (List.map (fun x -> H.li [ fix x ]) l) ]

src/printbox-md/PrintBox_md.ml

@@ -494,8 +494,10 @@ let pp c out b =
         (fun _out sub -> loop ~no_block ~no_md ~prefix:subprefix sub)
         out
       @@ Array.to_list body;
+      (* Note: vlist and tree element separators move to a new line.
+         A non-html hlist or table as a parent would not produce correct results. *)
       if c.Config.foldable_trees then
-        fprintf out "@,%s</details>@,%s@,%s" prefix prefix prefix
+        fprintf out "@,%s</details>@,%s" prefix prefix
     | B.Link { uri; inner } ->
       pp_print_string out "[";
       loop ~no_block:true ~no_md ~prefix:(prefix ^ " ") inner;

src/printbox-md/README.md

@@ -33,11 +33,9 @@ or if \`Bars are set, |  by the | vertical dash.
 
 <div>
  <table class="framed">
-  <tr class="">
-   <td class="">
-    <div class="">It only works when<br/>all the elements fit</div>
-   </td><td class=""><div class="">logically speaking,</div></td>
-   <td class=""><div class=""><b>on a single line.</b></div></td>
+  <tr><td><div>It only works when<br/>all the elements fit</div></td>
+   <td><div>logically speaking,</div></td>
+   <td><div><b>on a single line.</b></div></td>
   </tr>
  </table>
 </div>
@@ -46,13 +44,9 @@ or if \`Bars are set, |  by the | vertical dash.
 
 <div>
  <table class="non-framed">
-  <tr class="">
-   <td class=""><div class="">Otherwise, the fallback behavior is as if</div>
-   </td>
-   <td class=""><pre class="" style="font-family: monospace">`As_table</pre>
-   </td>
-   <td class=""><div class="">was used to configure horizontal boxes.</div>
-   </td>
+  <tr><td><div>Otherwise, the fallback behavior is as if</div></td>
+   <td><pre><span style="font-family: monospace">`As_table</span></pre></td>
+   <td><div>was used to configure horizontal boxes.</div></td>
   </tr>
  </table>
 </div>
@@ -105,7 +99,7 @@ to separate the entries (here with style \`Line_break).
 
 - And suprisingly it works even better
 - - when tables are configured
-  - <div><div style="border:thin solid"><div class="">to fallback on</div></div></div>
+  - <div><div style="border:thin solid"><div>to fallback on</div></div></div>
 
 
   - HTML -- but it doesn't work on GitHub Preview.
@@ -127,11 +121,9 @@ Trees are rendered as:
   - **are the details.**
   </details>
 
-
 </details>
 
 
-
 ### Tables
 
 There is a special case carved out for Markdown syntax tables.
@@ -143,29 +135,21 @@ Rows  |[must be]|single    |line.
 
 <div>
  <table class="framed">
-  <tr class=""><td class=""><div class=""><b>Tables</b></div></td>
-   <td class=""><div class=""><b>that meet</b></div></td>
-   <td class="">
-    <div style="border:thin solid"><div class=""><b>neither</b></div></div>
-   </td><td class=""><div class=""><b>of:</b></div></td>
+  <tr><td><div><b>Tables</b></div></td><td><div><b>that meet</b></div></td>
+   <td><div style="border:thin solid"><div><b>neither</b></div></div></td>
+   <td><div><b>of:</b></div></td>
   </tr>
-  <tr class="">
-   <td class="">
-    <div style="border:thin solid">
-     <div class=""><b>Markdown's native</b></div>
-    </div>
-   </td><td class=""><div class="">restrictions,</div></td>
-   <td class=""><div class="">special cases:</div></td>
-   <td class=""><pre class="" style="font-family: monospace">hlist
-                                                             vlist</pre>
-   </td>
+  <tr>
+   <td>
+    <div style="border:thin solid"><div><b>Markdown's native</b></div></div>
+   </td><td><div>restrictions,</div></td><td><div>special cases:</div></td>
+   <td><pre><span style="font-family: monospace">hlistvlist</span></pre></td>
   </tr>
-  <tr class=""><td class=""><div class="">End up</div></td>
-   <td class=""><div class="">as either</div></td>
-   <td class=""><div class="">of the fallbacks:</div></td>
-   <td class="">
-    <pre class="" style="font-family: monospace">printbox-text
-                                                 printbox-html
+  <tr><td><div>End up</div></td><td><div>as either</div></td>
+   <td><div>of the fallbacks:</div></td>
+   <td>
+    <pre>
+     <span style="font-family: monospace">printbox-textprintbox-html</span>
     </pre>
    </td>
   </tr>

test/test_html.expected

@@ -1,2 +1,2 @@
-<div><details><summary><span class="" style="border:thin solid">root</span></summary><ul><li><div style="border:thin solid"><div class="">child 1</div></div></li><li><div class="">child 2</div></li><li><div style="border:thin solid"><div><div></div><ul><li><details><summary><span class="" style="border:thin solid">header 3</span></summary><ul><li><div style="border:thin solid"><div class="">subchild 3</div></div></li></ul></details></li></ul></div></div></li><li><div><div></div><ul><li><details><summary><span class="" style="border:thin solid">header 4</span></summary><ul><li><div class="">subchild 4</div></li></ul></details></li></ul></div></li><li><div style="border:thin solid"><details><summary><span class="">header 5</span></summary><ul><li><div class="">subchild 5</div></li></ul></details></div></li><li><div style="border:thin solid"><div class="">child 5</div></div></li></ul></details></div>
+<div><details><summary><span style="border:thin solid">root</span></summary><ul><li><div style="border:thin solid"><div>child 1</div></div></li><li><div>child 2</div></li><li><div style="border:thin solid"><div><div></div><ul><li><details><summary><span style="border:thin solid">header 3</span></summary><ul><li><div style="border:thin solid"><div>subchild 3</div></div></li></ul></details></li></ul></div></div></li><li><div><div></div><ul><li><details><summary><span style="border:thin solid">header 4</span></summary><ul><li><div>subchild 4</div></li></ul></details></li></ul></div></li><li><div style="border:thin solid"><details><summary><span>header 5</span></summary><ul><li><div>subchild 5</div></li></ul></details></div></li><li><div style="border:thin solid"><div>child 5</div></div></li></ul></details></div>