JS dynamic bit string

2 files changed, 30 insertions, 12 deletions

diff --git a/src/gleam/dynamic.gleam b/src/gleam/dynamic.gleam
index 86d1b6e..903341a 100644
--- a/src/gleam/dynamic.gleam
+++ b/src/gleam/dynamic.gleam
@@ -60,22 +60,31 @@ if javascript {
     "../gleam_stdlib.js" "identity"
 }
 
+/// Checks to see whether a Dynamic value is a bit_string, and return the bit_string if
+/// it is.
+///
+/// ## Examples
+///
+///    > bit_string(from("Hello")) == bit_string.from_string("Hello")
+///    True
+///
+///    > bit_string(from(123))
+///    Error(DecodeError(expected: "BitString", found: "Int"))
+///
+pub fn bit_string(from data: Dynamic) -> Result(BitString, DecodeError) {
+  decode_bit_string(data)
+}
+
 if erlang {
-  /// Checks to see whether a Dynamic value is a bit_string, and return the bit_string if
-  /// it is.
-  ///
-  /// ## Examples
-  ///
-  ///    > bit_string(from("Hello")) == bit_string.from_string("Hello")
-  ///    True
-  ///
-  ///    > bit_string(from(123))
-  ///    Error(DecodeError(expected: "BitString", found: "Int"))
-  ///
-  pub external fn bit_string(from: Dynamic) -> Result(BitString, DecodeError) =
+  external fn decode_bit_string(Dynamic) -> Result(BitString, DecodeError) =
     "gleam_stdlib" "decode_bit_string"
 }
 
+if javascript {
+  external fn decode_bit_string(Dynamic) -> Result(BitString, DecodeError) =
+    "../gleam_stdlib.js" "decode_bit_string"
+}
+
 /// Checks to see whether a Dynamic value is a string, and return the string if
 /// it is.
 ///
diff --git a/src/gleam_stdlib.js b/src/gleam_stdlib.js
index b8feecf..0982f62 100644
--- a/src/gleam_stdlib.js
+++ b/src/gleam_stdlib.js
@@ -476,6 +476,8 @@ function classify_dynamic(data) {
     return "List";
   } else if (Number.isInteger(data)) {
     return "Int";
+  } else if (BitString.isBitString(data)) {
+    return "BitString";
   } else if (typeof data === "number") {
     return "Float";
   } else {
@@ -501,6 +503,13 @@ export function decode_int(data) {
 export function decode_float(data) {
   return typeof data === "number" ? new Ok(data) : decoder_error("Float", data);
 }
+
 export function decode_bool(data) {
   return typeof data === "boolean" ? new Ok(data) : decoder_error("Bool", data);
 }
+
+export function decode_bit_string(data) {
+  return BitString.isBitString(data)
+    ? new Ok(data)
+    : decoder_error("BitString", data);
+}