add a binary module

2 files changed, 35 insertions, 0 deletions

diff --git a/src/gleam/binary.gleam b/src/gleam/binary.gleam
new file mode 100644
index 0000000..1fa54a8
--- /dev/null
+++ b/src/gleam/binary.gleam
@@ -0,0 +1,23 @@
+//// Working with raw binary data.
+//// The Binary type should be used instead of a String type when not utf8 encoded.
+
+pub external type Binary
+
+/// Convert a utf8 String type into a raw Binary type.
+pub external fn from_string(String) -> Binary =
+  "gleam_stdlib" "identity"
+
+/// Extracts the part of a binary.
+///
+/// Binary part will start at given position and continue up to specified length.
+/// A negative length can be used to extract bytes at the end of a binary:
+pub external fn part(string: Binary, position: Int, length: Int) -> Binary = "binary" "part"
+
+
+/// Returns an integer which is the number of bytes in the binary.
+pub external fn byte_size(Binary) -> Int =
+  "erlang" "byte_size"
+
+// Not sure these will be necessary with bit syntax for for now I think they are
+pub external fn int_to_u32(Int) -> Result(Binary, Nil) = "binary_native" "int_to_u32"
+pub external fn int_from_u32(Binary) -> Result(Int, Nil) = "binary_native" "int_from_u32"
diff --git a/src/gleam/binary_native.erl b/src/gleam/binary_native.erl
new file mode 100644
index 0000000..d7e774c
--- /dev/null
+++ b/src/gleam/binary_native.erl
@@ -0,0 +1,12 @@
+-module (binary_native).
+-export ([int_to_u32/1, int_from_u32/1]).
+
+int_to_u32(I) when 0 =< I, I < 4294967296 ->
+  {ok, <<I:32>>};
+int_to_u32(_) ->
+  {error, nil}.
+
+int_from_u32(<<I:32>>) ->
+  {ok, I};
+int_from_u32(_) ->
+  {error, nil}.