use identity and direct string value in javascript ffi

2 files changed, 44 insertions, 25 deletions

diff --git a/src/gleam/json.gleam b/src/gleam/json.gleam
index 5670949..b8c49f6 100644
--- a/src/gleam/json.gleam
+++ b/src/gleam/json.gleam
@@ -38,8 +38,31 @@ pub fn decode(
   from json: String,
   using decoder: dynamic.Decoder(t),
 ) -> Result(t, DecodeError) {
-  let bits = bit_string.from_string(json)
-  decode_bits(bits, decoder)
+  do_decode(from: json, using: decoder)
+}
+
+if erlang {
+  fn do_decode(
+    from json: String,
+    using decoder: dynamic.Decoder(t),
+  ) -> Result(t, DecodeError) {
+    let bits = bit_string.from_string(json)
+    decode_bits(bits, decoder)
+  }
+}
+
+if javascript {
+  fn do_decode(
+    from json: String,
+    using decoder: dynamic.Decoder(t),
+  ) -> Result(t, DecodeError) {
+    try dynamic_value = decode_string(json)
+    decoder(dynamic_value)
+    |> result.map_error(UnexpectedFormat)
+  }
+
+  external fn decode_string(String) -> Result(Dynamic, DecodeError) =
+    "../gleam_json_ffi.mjs" "decode_string"
 }
 
 /// Decode a JSON bit string into dynamically typed data which can be decoded
@@ -158,7 +181,7 @@ if erlang {
 
 if javascript {
   external fn do_string(String) -> Json =
-    "../gleam_json_ffi.mjs" "string"
+    "../gleam_json_ffi.mjs" "identity"
 }
 
 /// Encode a bool into JSON.
@@ -181,7 +204,7 @@ if erlang {
 
 if javascript {
   external fn do_bool(Bool) -> Json =
-    "../gleam_json_ffi.mjs" "bool"
+    "../gleam_json_ffi.mjs" "identity"
 }
 
 /// Encode an int into JSON.
@@ -204,7 +227,7 @@ if erlang {
 
 if javascript {
   external fn do_int(Int) -> Json =
-    "../gleam_json_ffi.mjs" "int"
+    "../gleam_json_ffi.mjs" "identity"
 }
 
 /// Encode an float into JSON.
@@ -227,7 +250,7 @@ if erlang {
 
 if javascript {
   external fn do_float(input: Float) -> Json =
-    "../gleam_json_ffi.mjs" "float"
+    "../gleam_json_ffi.mjs" "identity"
 }
 
 /// The JSON value null.
@@ -297,7 +320,7 @@ if erlang {
 
 if javascript {
   external fn do_object(entries: List(#(String, Json))) -> Json =
-    "../gleam_json_ffi.mjs" "object_from"
+    "../gleam_json_ffi.mjs" "object"
 }
 
 /// Encode a list into a JSON array.
diff --git a/src/gleam_json_ffi.mjs b/src/gleam_json_ffi.mjs
index 0d9021c..64d90b0 100644
--- a/src/gleam_json_ffi.mjs
+++ b/src/gleam_json_ffi.mjs
@@ -6,10 +6,14 @@ export function json_to_string(json) {
   return JSON.stringify(json)
 }
 
-export function object_from(entries) {
+export function object(entries) {
   return Object.fromEntries(entries)
 }
 
+export function identity(x) {
+  return x
+}
+
 export function array(list) {
   return list.toArray()
 }
@@ -18,23 +22,6 @@ export function do_null() {
   return null
 }
 
-export function string(x) {
-  return json_to_string(x)
-}
-
-export function int(x) {
-  return parseInt(json_to_string(x), 10)
-}
-
-export function float(x) {
-  return parseFloat(json_to_string(x), 10)
-}
-
-export function bool(x) {
-  return Boolean(x)
-}
-
-
 export function decode(bit_string) {
   const stringResult = bit_string_to_string(bit_string)
   if (!stringResult.isOk()) return stringResult
@@ -46,6 +33,15 @@ export function decode(bit_string) {
   }
 }
 
+export function decode_string_to_dynamic(string) {
+  try {
+    const result = JSON.parse(string)
+    return new Ok(result)
+  } catch (err) {
+    return new Error(getJsonDecodeError(err))
+  }
+}
+
 function getJsonDecodeError(stdErr) {
   if (isUnexpectedByte(stdErr)) return new toUnexpectedByteError(stdErr)
   if (isUnexpectedEndOfInput(stdErr)) return new UnexpectedEndOfInput()