From 5c2a2c277d4098deca2e7346d675f6a47a91e761 Mon Sep 17 00:00:00 2001
From: Patrick Smith <pgwsmith@gmail.com>
Date: Sun, 30 Jun 2024 14:16:37 +1000
Subject: [PATCH] Breaking change: Flip Memory.Slice 64-bit representation
 around

Smallest digits are on the right
---
 lib/orb/memory/slice.ex        | 14 +++++++-------
 test/i32/conveniences_test.exs |  1 -
 test/memory_slice_test.exs     | 13 ++++++-------
 3 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/lib/orb/memory/slice.ex b/lib/orb/memory/slice.ex
index 561c921..079d1cd 100644
--- a/lib/orb/memory/slice.ex
+++ b/lib/orb/memory/slice.ex
@@ -19,14 +19,14 @@ defmodule Orb.Memory.Slice do
         byte_length::unsigned-little-integer-size(32)>>
 
     import Bitwise
-    byte_offset <<< 32 ||| byte_length
+    byte_length <<< 32 ||| byte_offset
   end
 
   def from(byte_offset = %{push_type: _}, byte_length = %{push_type: _}) do
-    byte_length
+    byte_offset
     |> I64.extend_i32_u()
     |> I64.or(
-      I64.extend_i32_u(byte_offset)
+      I64.extend_i32_u(byte_length)
       |> I64.shl(32)
     )
   end
@@ -36,7 +36,7 @@ defmodule Orb.Memory.Slice do
     #   <<n::unsigned-little-integer-size(64)>>
 
     import Bitwise
-    n >>> 32
+    n &&& 0xFFFFFFFF
   end
 
   def get_byte_offset(
@@ -46,7 +46,7 @@ defmodule Orb.Memory.Slice do
   end
 
   def get_byte_offset(range = %{push_type: _}) do
-    I64.shr_u(range, 32) |> I32.wrap_i64()
+    I32.wrap_i64(range)
   end
 
   def get_byte_length(n) when is_integer(n) do
@@ -56,7 +56,7 @@ defmodule Orb.Memory.Slice do
     # byte_length
 
     import Bitwise
-    n &&& 0xFFFFFFFF
+    n >>> 32
   end
 
   def get_byte_length(
@@ -66,7 +66,7 @@ defmodule Orb.Memory.Slice do
   end
 
   def get_byte_length(range = %{push_type: _}) do
-    I32.wrap_i64(range)
+    I64.shr_u(range, 32) |> I32.wrap_i64()
   end
 
   # defimpl Orb.ToWat do
diff --git a/test/i32/conveniences_test.exs b/test/i32/conveniences_test.exs
index 12082ca..0b86573 100644
--- a/test/i32/conveniences_test.exs
+++ b/test/i32/conveniences_test.exs
@@ -110,7 +110,6 @@ defmodule I32ConveniencesTest do
       end
 
     assert wat =~ "Method not allowed"
-    IO.puts(wat)
 
     assert 255 = Instance.run(wat) |> Instance.call(:ptr)
 
diff --git a/test/memory_slice_test.exs b/test/memory_slice_test.exs
index 2427da3..0029abb 100644
--- a/test/memory_slice_test.exs
+++ b/test/memory_slice_test.exs
@@ -39,20 +39,19 @@ defmodule MemorySliceTest do
       b = 2
       c = Memory.Slice.from(a, b)
 
-      # assert!(c === i64(0x0000000F00000002))
-      # a = Memory.Slice.get_byte_offset(c)
-      # assert!(a === i32(0x0F))
-      # b = Memory.Slice.get_byte_length(c)
-      # assert!(b === i32(2))
+      assert!(c === i64(0x000000020000000F))
+      a = Memory.Slice.get_byte_offset(c)
+      assert!(a === i32(0x0F))
+      b = Memory.Slice.get_byte_length(c)
+      assert!(b === i32(2))
 
       {c, Memory.Slice.get_byte_offset(c), Memory.Slice.get_byte_length(c)}
     end
   end
 
   test "in WebAssembly" do
-    MemorySliceSubject |> Orb.to_wat() |> IO.puts()
     {c, a, b} = OrbWasmtime.Wasm.call(MemorySliceSubject, :test)
-    assert c === 0x0000000F00000002
+    assert c === 0x000000020000000F
     assert a === 0x0F
     assert b === 2
   end