Merge pull request #55 from Ngoguey42/fix-nan-json-encoding

Fix JSON encoder regarding NaNs
mirage · Apr 27, 2021 · 0031d4a · 0031d4a
2 parents 17a1c2a + 421d47a
commit 0031d4a
Show file tree

Hide file tree

Showing 3 changed files with 8 additions and 1 deletion.
diff --git a/CHANGES.md b/CHANGES.md
@@ -18,6 +18,9 @@
 
 - Add a JSON object combinator: `Json.assoc` (#53, @Ngoguey42)
 
+- Drop the payload of NaN floating point values during JSON encoding. `-nan`
+  strings are not emitted any more. (#55, @Ngoguey42)
+
 ### 0.2.1 (2021-01-18)
 
 - Support Ppxlib versions >= 0.18.0. (#35, @CraigFe)

diff --git a/src/repr/type_json.ml b/src/repr/type_json.ml
@@ -43,7 +43,9 @@ module Encode = struct
 
   let float e f =
     match classify_float f with
-    | FP_nan | FP_infinite -> lexeme e (`String (string_of_float f))
+    | FP_nan -> lexeme e (`String "nan")
+    | FP_infinite when Float.sign_bit f -> lexeme e (`String "-inf")
+    | FP_infinite -> lexeme e (`String "inf")
     | _ -> lexeme e (`Float f)
 
   let int e i = float e (float_of_int i)

diff --git a/test/repr/main.ml b/test/repr/main.ml
@@ -190,6 +190,8 @@ let test_json_option () =
     x
 
 let test_json_float () =
+  let x = T.to_json_string T.float (-.Float.nan) in
+  Alcotest.(check string) "-NaN to JSON" "\"nan\"" x;
   let x = T.to_json_string T.float Float.nan in
   Alcotest.(check string) "NaN to JSON" "\"nan\"" x;
   let x = T.to_json_string T.float Float.infinity in