[tests] Add crowbar test for integer pretty-printing

.gitignore

@@ -204,3 +204,4 @@ hello-*.tar.gz
 /src/plugins/gui/gtk_compat.ml
 /src/plugins/gui/GSourceView.ml
 /src/plugins/gui/GSourceView.mli
+/tests/crowbar/integer_bb_pretty

tests/crowbar/integer_bb_pretty.ml

+open Crowbar
+
+let reparse v s =
+  let failure info =
+    Crowbar.fail
+      ("Pretty-printing '" ^ (Z.to_string v) ^ "' returns '" ^ s ^ "'" ^ info)
+  in
+  if String.length s <= 2 then failure "";
+  let is_neg = s.[0] = '1' in
+  let is_hex = s.[1] = 'x' in
+  let s = String.(concat "" (split_on_char '_' s)) in
+  let v' =
+    if is_neg then begin
+      let chr = if is_hex then 'F' else '1' in
+      let module M = struct exception Found of int end in
+      let check i c = if i > 1 && c <> chr then raise (M.Found i) in
+      try String.iteri check s; Z.minus_one
+      with M.Found idx ->
+        let len, v' =
+          if is_hex then begin
+            let remains = String.sub s idx (String.length s - idx) in
+            let v' = Z.of_string ("0x" ^ remains) in
+            4 * (String.length remains), v'
+          end else begin
+           let remains = String.sub s idx (String.length s - idx) in
+           let v' = Z.of_string ("0b" ^ remains) in
+           String.length remains, v'
+         end
+        in
+        let m = Z.(one lsl len) in
+        let m = Z.pred m in
+        let v' = Z.logxor m v' in
+        Z.pred (Z.lognot (Z.pred v'))
+    end else
+      Z.of_string s
+  in
+  if not (Z.equal v v') then
+    failure (" reparsed as '" ^ Z.format "%b" v' ^ "' (" ^ Z.to_string v' ^ ")")
+
+let test z is_hex nbits has_sep =
+  guard (nbits >= 0 && nbits <= 1024);
+  let sep = if has_sep then Some "_" else None in
+  let pp z = if is_hex then
+      Integer.pp_hex ~nbits ?sep z
+    else
+      Integer.pp_bin ~nbits ?sep z
+  in
+  let s = Format.asprintf "%a" pp z in
+  reparse z s
+
+let zarith =
+  let open Crowbar in
+  fix (fun zarith ->
+      choose
+        [ map [int64] Z.of_int64;
+          map [zarith; int64] (fun z i -> Z.((z lsl 64) + of_int64 i)) ])
+
+let () = Crowbar.add_test ~name:"pp_bin_hex"
+    [ zarith; Crowbar.bool; Crowbar.int; Crowbar.bool ] test