make serializer work correct

.gitignore

@@ -1 +1,2 @@
 .stack-work
+tests/runnable/*

src/Language/Wasm/Binary.hs

@@ -1,7 +1,8 @@
 {-# LANGUAGE NamedFieldPuns #-}
 
 module Language.Wasm.Binary (
-    
+    dumpModule,
+    dumpModuleLazy
 ) where
 
 import Language.Wasm.Structure
@@ -542,7 +543,7 @@ instance Serialize Module where
 
         putSection TypeSection $ putVec $ types mod
         putSection ImportSection $ putVec $ imports mod
-        putSection FunctionSection $ putVec $ map funcType $ functions mod
+        putSection FunctionSection $ putVec $ map (Index . funcType) $ functions mod
         putSection TableSection $ putVec $ tables mod
         putSection MemorySection $ putVec $ mems mod
         putSection GlobalSection $ putVec $ globals mod
@@ -555,3 +556,9 @@ instance Serialize Module where
         putSection DataSection $ putVec $ datas mod
         
     get = undefined
+
+dumpModule :: Module -> BS.ByteString
+dumpModule = encode
+
+dumpModuleLazy :: Module -> LBS.ByteString
+dumpModuleLazy = encodeLazy

tests/Test.hs

@@ -12,6 +12,7 @@ import qualified Data.ByteString.Lazy as LBS
 import qualified Language.Wasm.Lexer as Lexer
 import qualified Language.Wasm.Parser as Parser
 import qualified Language.Wasm.Structure as Structure
+import qualified Language.Wasm.Binary as Binary
 
 import qualified Debug.Trace as Debug
 
@@ -19,9 +20,17 @@ isRight :: (Show b) => Either a b -> Bool
 isRight (Right x) = x `seq` True
 isRight _         = False
 
+compile :: String -> IO ()
+compile file = do
+  content <- LBS.readFile $ "tests/samples/" ++ file
+  let Right mod = Parser.parseModule <$> Lexer.scanner content
+  LBS.writeFile ("tests/runnable/" ++ file) $ Binary.dumpModuleLazy mod
+  -- to run: python -m SimpleHTTPServer 8081 && open http://localhost:8081/tests/runnable
+
 main :: IO ()
 main = do
   files <- Directory.listDirectory "tests/samples"
+  compile "fact.wast"
   testCases <- (`mapM` files) $ \file -> do
     content <- LBS.readFile $ "tests/samples/" ++ file
     let result = Parser.parseModule <$> Lexer.scanner content

tests/runnable/index.html

@@ -0,0 +1,11 @@
+<script>
+    fetch('fact.wast').then(response =>
+        response.arrayBuffer()
+    ).then(bytes =>
+        WebAssembly.instantiate(bytes, {})
+    ).then(results => {
+        console.log('result', results)
+        const fact = results.instance.exports['fac-iter-named-32']
+        console.log(fact, fact(5))
+    });
+</script>

tests/samples/fact.wast

@@ -65,6 +65,28 @@
     (get_local $res)
   )
 
+  ;; Iterative factorial named
+  (func (export "fac-iter-named-32") (param $n i32) (result i32)
+    (local $i i32)
+    (local $res i32)
+    (set_local $i (get_local $n))
+    (set_local $res (i32.const 1))
+    (block $done
+      (loop $loop
+        (if
+          (i32.eq (get_local $i) (i32.const 0))
+          (then (br $done))
+          (else
+            (set_local $res (i32.mul (get_local $i) (get_local $res)))
+            (set_local $i (i32.sub (get_local $i) (i32.const 1)))
+          )
+        )
+        (br $loop)
+      )
+    )
+    (get_local $res)
+  )
+
   ;; Optimized factorial.
   (func (export "fac-opt") (param i64) (result i64)
     (local i64)