diff --git a/src/Language/Wasm/Parser.y b/src/Language/Wasm/Parser.y
index 78d3c48..0db71d8 100644
--- a/src/Language/Wasm/Parser.y
+++ b/src/Language/Wasm/Parser.y
@@ -553,12 +553,25 @@ foldedinstr :: { [Instruction] }
 foldedinst1 :: { [Instruction] }
     : plaininstr list(foldedinstr) ')' { concat $2 ++ [PlainInstr $1] }
     | 'call_indirect' folded_call_indirect { $2 }
-    | 'block' opt(ident) opt(resulttype) list(instr) ')' { [BlockInstr $2 (fromMaybe [] $3) $4] }
-    | 'loop' opt(ident) opt(resulttype) list(instr) ')' { [LoopInstr $2 (fromMaybe [] $3) $4] }
+    | 'block' opt(ident) folded_block { [$3 $2] }
+    | 'loop' opt(ident) folded_loop { [$3 $2] }
     | 'if' opt(ident) '(' folded_if_result { $4 $2 }
-        -- opt(resulttype) list(foldedinstr)
-        -- '(' 'then' list(instr) ')'
-        -- '(' 'else' list(instr) opt(')') ')' { concat $4 ++ [IfInstr $2 (fromMaybe [] $3) $7 $11] }
+
+folded_block :: { Maybe Ident -> Instruction }
+    : ')' { \ident -> BlockInstr ident [] [] }
+    | '(' folded_block1 { $2 }
+
+folded_block1 :: { Maybe Ident -> Instruction }
+    : 'result' valtype ')' list(foldedinstr) ')' { \ident -> BlockInstr ident [$2] (concat $4) }
+    | foldedinst1 list(foldedinstr) ')' { \ident -> BlockInstr ident [] ($1 ++ concat $2) }
+
+folded_loop :: { Maybe Ident -> Instruction }
+    : ')' { \ident -> LoopInstr ident [] [] }
+    | '(' folded_loop1 { $2 }
+
+folded_loop1 :: { Maybe Ident -> Instruction }
+    : 'result' valtype ')' list(foldedinstr) ')' { \ident -> LoopInstr ident [$2] (concat $4) }
+    | foldedinst1 list(foldedinstr) ')' { \ident -> LoopInstr ident [] ($1 ++ concat $2) }
 
 folded_if_result :: { Maybe Ident -> [Instruction] }
     : 'result' valtype ')' '(' folded_then_else { \ident -> [IfInstr ident [$2] (fst $5) (snd $5)] }
diff --git a/tests/Test.hs b/tests/Test.hs
index ca8a657..3ae6d67 100644
--- a/tests/Test.hs
+++ b/tests/Test.hs
@@ -12,6 +12,6 @@ import qualified Language.Wasm.Parser as Parser
 
 main :: IO ()
 main = do
-  file <- LBS.readFile "tests/samples/if.wast"
+  file <- LBS.readFile "tests/samples/loop.wast"
   print $ Parser.parseModule <$> Lexer.scanner file
   defaultMain $ testGroup "Test Suite" []
diff --git a/tests/samples/block.wast b/tests/samples/block.wast
new file mode 100644
index 0000000..cec7c2d
--- /dev/null
+++ b/tests/samples/block.wast
@@ -0,0 +1,138 @@
+;; Test `block` operator
+
+(module
+  ;; Auxiliary definition
+  (func $dummy)
+
+  (func (export "empty")
+    (block)
+    (block $l)
+  )
+
+  (func (export "singular") (result i32)
+    (block (nop))
+    (block (result i32) (i32.const 7))
+  )
+
+  (func (export "multi") (result i32)
+    (block (call $dummy) (call $dummy) (call $dummy) (call $dummy))
+    (block (result i32) (call $dummy) (call $dummy) (call $dummy) (i32.const 8))
+  )
+
+  (func (export "nested") (result i32)
+    (block (result i32)
+      (block (call $dummy) (block) (nop))
+      (block (result i32) (call $dummy) (i32.const 9))
+    )
+  )
+
+  (func (export "deep") (result i32)
+    (block (result i32) (block (result i32)
+      (block (result i32) (block (result i32)
+        (block (result i32) (block (result i32)
+          (block (result i32) (block (result i32)
+            (block (result i32) (block (result i32)
+              (block (result i32) (block (result i32)
+                (block (result i32) (block (result i32)
+                  (block (result i32) (block (result i32)
+                    (block (result i32) (block (result i32)
+                      (block (result i32) (block (result i32)
+                        (block (result i32) (block (result i32)
+                          (block (result i32) (block (result i32)
+                            (block (result i32) (block (result i32)
+                              (block (result i32) (block (result i32)
+                                (block (result i32) (block (result i32)
+                                  (block (result i32) (block (result i32)
+                                    (block (result i32) (block (result i32)
+                                      (block (result i32) (block (result i32)
+                                        (block (result i32) (block (result i32)
+                                          (call $dummy) (i32.const 150)
+                                        ))
+                                      ))
+                                    ))
+                                  ))
+                                ))
+                              ))
+                            ))
+                          ))
+                        ))
+                      ))
+                    ))
+                  ))
+                ))
+              ))
+            ))
+          ))
+        ))
+      ))
+    ))
+  )
+
+  (func (export "as-unary-operand") (result i32)
+    (i32.ctz (block (result i32) (call $dummy) (i32.const 13)))
+  )
+  (func (export "as-binary-operand") (result i32)
+    (i32.mul
+      (block (result i32) (call $dummy) (i32.const 3))
+      (block (result i32) (call $dummy) (i32.const 4))
+    )
+  )
+  (func (export "as-test-operand") (result i32)
+    (i32.eqz (block (result i32) (call $dummy) (i32.const 13)))
+  )
+  (func (export "as-compare-operand") (result i32)
+    (f32.gt
+      (block (result f32) (call $dummy) (f32.const 3))
+      (block (result f32) (call $dummy) (f32.const 3))
+    )
+  )
+
+  (func (export "break-bare") (result i32)
+    (block (br 0) (unreachable))
+    (block (br_if 0 (i32.const 1)) (unreachable))
+    (block (br_table 0 (i32.const 0)) (unreachable))
+    (block (br_table 0 0 0 (i32.const 1)) (unreachable))
+    (i32.const 19)
+  )
+  (func (export "break-value") (result i32)
+    (block (result i32) (br 0 (i32.const 18)) (i32.const 19))
+  )
+  (func (export "break-repeated") (result i32)
+    (block (result i32)
+      (br 0 (i32.const 18))
+      (br 0 (i32.const 19))
+      (drop (br_if 0 (i32.const 20) (i32.const 0)))
+      (drop (br_if 0 (i32.const 20) (i32.const 1)))
+      (br 0 (i32.const 21))
+      (br_table 0 (i32.const 22) (i32.const 4))
+      (br_table 0 0 0 (i32.const 23) (i32.const 1))
+      (i32.const 21)
+    )
+  )
+  (func (export "break-inner") (result i32)
+    (local i32)
+    (set_local 0 (i32.const 0))
+    (set_local 0 (i32.add (get_local 0) (block (result i32) (block (result i32) (br 1 (i32.const 0x1))))))
+    (set_local 0 (i32.add (get_local 0) (block (result i32) (block (br 0)) (i32.const 0x2))))
+    (set_local 0
+      (i32.add (get_local 0) (block (result i32) (i32.ctz (br 0 (i32.const 0x4)))))
+    )
+    (set_local 0
+      (i32.add (get_local 0) (block (result i32) (i32.ctz (block (result i32) (br 1 (i32.const 0x8))))))
+    )
+    (get_local 0)
+  )
+
+  (func (export "effects") (result i32)
+    (local i32)
+    (block
+      (set_local 0 (i32.const 1))
+      (set_local 0 (i32.mul (get_local 0) (i32.const 3)))
+      (set_local 0 (i32.sub (get_local 0) (i32.const 5)))
+      (set_local 0 (i32.mul (get_local 0) (i32.const 7)))
+      (br 0)
+      (set_local 0 (i32.mul (get_local 0) (i32.const 100)))
+    )
+    (i32.eq (get_local 0) (i32.const -14))
+  )
+)
\ No newline at end of file
diff --git a/tests/samples/if.wast b/tests/samples/if.wast
new file mode 100644
index 0000000..b827c5e
--- /dev/null
+++ b/tests/samples/if.wast
@@ -0,0 +1,132 @@
+;; Test `if` operator
+
+(module
+  ;; Auxiliary definition
+  (func $dummy)
+
+  (func (export "empty") (param i32)
+    (if (get_local 0) (then))
+    (if (get_local 0) (then) (else))
+    (if $l (get_local 0) (then))
+    (if $l (get_local 0) (then) (else))
+  )
+
+  (func (export "singular") (param i32) (result i32)
+    (if (get_local 0) (then (nop)))
+    (if (get_local 0) (then (nop)) (else (nop)))
+    (if (result i32) (get_local 0) (then (i32.const 7)) (else (i32.const 8)))
+  )
+
+  (func (export "multi") (param i32) (result i32)
+    (if (get_local 0) (then (call $dummy) (call $dummy) (call $dummy)))
+    (if (get_local 0) (then) (else (call $dummy) (call $dummy) (call $dummy)))
+    (if (result i32) (get_local 0)
+      (then (call $dummy) (call $dummy) (i32.const 8))
+      (else (call $dummy) (call $dummy) (i32.const 9))
+    )
+  )
+
+  (func (export "nested") (param i32 i32) (result i32)
+    (if (result i32) (get_local 0)
+      (then
+        (if (get_local 1) (then (call $dummy) (block) (nop)))
+        (if (get_local 1) (then) (else (call $dummy) (block) (nop)))
+        (if (result i32) (get_local 1)
+          (then (call $dummy) (i32.const 9))
+          (else (call $dummy) (i32.const 10))
+        )
+      )
+      (else
+        (if (get_local 1) (then (call $dummy) (block) (nop)))
+        (if (get_local 1) (then) (else (call $dummy) (block) (nop)))
+        (if (result i32) (get_local 1)
+          (then (call $dummy) (i32.const 10))
+          (else (call $dummy) (i32.const 11))
+        )
+      )
+    )
+  )
+
+  (func (export "as-unary-operand") (param i32) (result i32)
+    (i32.ctz
+      (if (result i32) (get_local 0)
+        (then (call $dummy) (i32.const 13))
+        (else (call $dummy) (i32.const -13))
+      )
+    )
+  )
+  (func (export "as-binary-operand") (param i32 i32) (result i32)
+    (i32.mul
+      (if (result i32) (get_local 0)
+        (then (call $dummy) (i32.const 3))
+        (else (call $dummy) (i32.const -3))
+      )
+      (if (result i32) (get_local 1)
+        (then (call $dummy) (i32.const 4))
+        (else (call $dummy) (i32.const -5))
+      )
+    )
+  )
+  (func (export "as-test-operand") (param i32) (result i32)
+    (i32.eqz
+      (if (result i32) (get_local 0)
+        (then (call $dummy) (i32.const 13))
+        (else (call $dummy) (i32.const 0))
+      )
+    )
+  )
+  (func (export "as-compare-operand") (param i32 i32) (result i32)
+    (f32.gt
+      (if (result f32) (get_local 0)
+        (then (call $dummy) (f32.const 3))
+        (else (call $dummy) (f32.const -3))
+      )
+      (if (result f32) (get_local 1)
+        (then (call $dummy) (f32.const 4))
+        (else (call $dummy) (f32.const -4))
+      )
+    )
+  )
+
+  (func (export "break-bare") (result i32)
+    (if (i32.const 1) (then (br 0) (unreachable)))
+    (if (i32.const 1) (then (br 0) (unreachable)) (else (unreachable)))
+    (if (i32.const 0) (then (unreachable)) (else (br 0) (unreachable)))
+    (if (i32.const 1) (then (br_if 0 (i32.const 1)) (unreachable)))
+    (if (i32.const 1) (then (br_if 0 (i32.const 1)) (unreachable)) (else (unreachable)))
+    (if (i32.const 0) (then (unreachable)) (else (br_if 0 (i32.const 1)) (unreachable)))
+    (if (i32.const 1) (then (br_table 0 (i32.const 0)) (unreachable)))
+    (if (i32.const 1) (then (br_table 0 (i32.const 0)) (unreachable)) (else (unreachable)))
+    (if (i32.const 0) (then (unreachable)) (else (br_table 0 (i32.const 0)) (unreachable)))
+    (i32.const 19)
+  )
+
+  (func (export "break-value") (param i32) (result i32)
+    (if (result i32) (get_local 0)
+      (then (br 0 (i32.const 18)) (i32.const 19))
+      (else (br 0 (i32.const 21)) (i32.const 20))
+    )
+  )
+
+  (func (export "effects") (param i32) (result i32)
+    (local i32)
+    (if
+      (block (result i32) (set_local 1 (i32.const 1)) (get_local 0))
+      (then
+        (set_local 1 (i32.mul (get_local 1) (i32.const 3)))
+        (set_local 1 (i32.sub (get_local 1) (i32.const 5)))
+        (set_local 1 (i32.mul (get_local 1) (i32.const 7)))
+        (br 0)
+        (set_local 1 (i32.mul (get_local 1) (i32.const 100)))
+      )
+      (else
+        (set_local 1 (i32.mul (get_local 1) (i32.const 5)))
+        (set_local 1 (i32.sub (get_local 1) (i32.const 7)))
+        (set_local 1 (i32.mul (get_local 1) (i32.const 3)))
+        (br 0)
+        (set_local 1 (i32.mul (get_local 1) (i32.const 1000)))
+      )
+    )
+    (get_local 1)
+  )
+)
\ No newline at end of file
diff --git a/tests/samples/import.wast b/tests/samples/import.wast
new file mode 100644
index 0000000..ebc0392
--- /dev/null
+++ b/tests/samples/import.wast
@@ -0,0 +1,67 @@
+(module
+  (type $func_i32 (func (param i32)))
+  (type $func_i64 (func (param i64)))
+  (type $func_f32 (func (param f32)))
+  (type $func_f64 (func (param f64)))
+
+  (import "spectest" "print" (func (param i32)))
+  ;; JavaScript can't handle i64 yet.
+  ;; (func (import "spectest" "print") (param i64))
+  (import "spectest" "print" (func $print_i32 (param i32)))
+  ;; JavaScript can't handle i64 yet.
+  ;; (import "spectest" "print" (func $print_i64 (param i64)))
+  (import "spectest" "print" (func $print_f32 (param f32)))
+  (import "spectest" "print" (func $print_f64 (param f64)))
+  (import "spectest" "print" (func $print_i32_f32 (param i32 f32)))
+  (import "spectest" "print" (func $print_f64_f64 (param f64 f64)))
+  (func $print_i32-2 (import "spectest" "print") (param i32))
+  (func $print_f64-2 (import "spectest" "print") (param f64))
+  (import "test" "func-i64->i64" (func $i64->i64 (param i64) (result i64)))
+
+  (func (export "p1") (import "spectest" "print") (param i32))
+  (func $p (export "p2") (import "spectest" "print") (param i32))
+  (func (export "p3") (export "p4") (import "spectest" "print") (param i32))
+  (func (export "p5") (import "spectest" "print") (type 0))
+  (func (export "p6") (import "spectest" "print") (type 0) (param i32) (result))
+
+  (import "spectest" "print" (func (type $forward)))
+  (func (import "spectest" "print") (type $forward))
+  (type $forward (func (param i32)))
+
+  (table anyfunc (elem $print_i32 $print_f64))
+  (table (export "my-table") anyfunc (elem $print_i32 $print_f64))
+  (table (export "my-table") (export "my-table2") anyfunc (elem $print_i32 $print_f64))
+  (table (import "external-mod" "external-table") 0 anyfunc)
+  (table (export "my-table") (import "external-mod" "external-table") 0 anyfunc)
+  (table (export "my-table") (export "my-table2") (import "external-mod" "external-table") 0 anyfunc)
+
+  (func (export "print32") (param $i i32)
+    (local $x f32)
+    (set_local $x (f32.convert_s/i32 (get_local $i)))
+    (call 0 (get_local $i))
+    (call $print_i32_f32
+      (i32.add (get_local $i) (i32.const 1))
+      (f32.const 42)
+    )
+    (call $print_i32 (get_local $i))
+    (call $print_i32-2 (get_local $i))
+    (call $print_f32 (get_local $x))
+    (call_indirect (type $func_i32) (get_local $i) (i32.const 0))
+  )
+
+  (func (export "print64") (param $i i64)
+    (local $x f64)
+    (set_local $x (f64.convert_s/i64 (call $i64->i64 (get_local $i))))
+    ;; JavaScript can't handle i64 yet.
+    ;; (call 1 (get_local $i))
+    (call $print_f64_f64
+      (f64.add (get_local $x) (f64.const 1))
+      (f64.const 53)
+    )
+    ;; JavaScript can't handle i64 yet.
+    ;; (call $print_i64 (get_local $i))
+    (call $print_f64 (get_local $x))
+    (call $print_f64-2 (get_local $x))
+    (call_indirect (type $func_f64) (get_local $x) (i32.const 1))
+  )
+)
\ No newline at end of file
diff --git a/tests/samples/loop.wast b/tests/samples/loop.wast
new file mode 100644
index 0000000..3cb586d
--- /dev/null
+++ b/tests/samples/loop.wast
@@ -0,0 +1,202 @@
+;; Test `loop` opcode
+
+(module
+  (func $dummy)
+
+  (func (export "empty")
+    (loop)
+    (loop $l)
+  )
+
+  (func (export "singular") (result i32)
+    (loop (nop))
+    (loop (result i32) (i32.const 7))
+  )
+
+  (func (export "multi") (result i32)
+    (loop (call $dummy) (call $dummy) (call $dummy) (call $dummy))
+    (loop (result i32) (call $dummy) (call $dummy) (call $dummy) (i32.const 8))
+  )
+
+  (func (export "nested") (result i32)
+    (loop (result i32)
+      (loop (call $dummy) (block) (nop))
+      (loop (result i32) (call $dummy) (i32.const 9))
+    )
+  )
+
+  (func (export "deep") (result i32)
+    (loop (result i32) (block (result i32)
+      (loop (result i32) (block (result i32)
+        (loop (result i32) (block (result i32)
+          (loop (result i32) (block (result i32)
+            (loop (result i32) (block (result i32)
+              (loop (result i32) (block (result i32)
+                (loop (result i32) (block (result i32)
+                  (loop (result i32) (block (result i32)
+                    (loop (result i32) (block (result i32)
+                      (loop (result i32) (block (result i32)
+                        (loop (result i32) (block (result i32)
+                          (loop (result i32) (block (result i32)
+                            (loop (result i32) (block (result i32)
+                              (loop (result i32) (block (result i32)
+                                (loop (result i32) (block (result i32)
+                                  (loop (result i32) (block (result i32)
+                                    (loop (result i32) (block (result i32)
+                                      (loop (result i32) (block (result i32)
+                                        (loop (result i32) (block (result i32)
+                                          (loop (result i32) (block (result i32)
+                                            (call $dummy) (i32.const 150)
+                                          ))
+                                        ))
+                                      ))
+                                    ))
+                                  ))
+                                ))
+                              ))
+                            ))
+                          ))
+                        ))
+                      ))
+                    ))
+                  ))
+                ))
+              ))
+            ))
+          ))
+        ))
+      ))
+    ))
+  )
+
+  (func (export "as-unary-operand") (result i32)
+    (i32.ctz (loop (result i32) (call $dummy) (i32.const 13)))
+  )
+  (func (export "as-binary-operand") (result i32)
+    (i32.mul
+      (loop (result i32) (call $dummy) (i32.const 3))
+      (loop (result i32) (call $dummy) (i32.const 4))
+    )
+  )
+  (func (export "as-test-operand") (result i32)
+    (i32.eqz (loop (result i32) (call $dummy) (i32.const 13)))
+  )
+  (func (export "as-compare-operand") (result i32)
+    (f32.gt
+      (loop (result f32) (call $dummy) (f32.const 3))
+      (loop (result f32) (call $dummy) (f32.const 3))
+    )
+  )
+
+  (func (export "break-bare") (result i32)
+    (block (loop (br 1) (br 0) (unreachable)))
+    (block (loop (br_if 1 (i32.const 1)) (unreachable)))
+    (block (loop (br_table 1 (i32.const 0)) (unreachable)))
+    (block (loop (br_table 1 1 1 (i32.const 1)) (unreachable)))
+    (i32.const 19)
+  )
+  (func (export "break-value") (result i32)
+    (block (result i32)
+      (loop (result i32) (br 1 (i32.const 18)) (br 0) (i32.const 19))
+    )
+  )
+  (func (export "break-repeated") (result i32)
+    (block (result i32)
+      (loop (result i32)
+        (br 1 (i32.const 18))
+        (br 1 (i32.const 19))
+        (drop (br_if 1 (i32.const 20) (i32.const 0)))
+        (drop (br_if 1 (i32.const 20) (i32.const 1)))
+        (br 1 (i32.const 21))
+        (br_table 1 (i32.const 22) (i32.const 0))
+        (br_table 1 1 1 (i32.const 23) (i32.const 1))
+        (i32.const 21)
+      )
+    )
+  )
+  (func (export "break-inner") (result i32)
+    (local i32)
+    (set_local 0 (i32.const 0))
+    (set_local 0 (i32.add (get_local 0) (block (result i32) (loop (result i32) (block (result i32) (br 2 (i32.const 0x1)))))))
+    (set_local 0 (i32.add (get_local 0) (block (result i32) (loop (result i32) (loop (result i32) (br 2 (i32.const 0x2)))))))
+    (set_local 0 (i32.add (get_local 0) (block (result i32) (loop (result i32) (block (result i32) (loop (result i32) (br 1 (i32.const 0x4))))))))
+    (set_local 0 (i32.add (get_local 0) (block (result i32) (loop (result i32) (i32.ctz (br 1 (i32.const 0x8)))))))
+    (set_local 0 (i32.add (get_local 0) (block (result i32) (loop (result i32) (i32.ctz (loop (result i32) (br 2 (i32.const 0x10))))))))
+    (get_local 0)
+  )
+  (func (export "cont-inner") (result i32)
+    (local i32)
+    (set_local 0 (i32.const 0))
+    (set_local 0 (i32.add (get_local 0) (loop (result i32) (loop (result i32) (br 1)))))
+    (set_local 0 (i32.add (get_local 0) (loop (result i32) (i32.ctz (br 0)))))
+    (set_local 0 (i32.add (get_local 0) (loop (result i32) (i32.ctz (loop (result i32) (br 1))))))
+    (get_local 0)
+  )
+
+  (func $fx (export "effects") (result i32)
+    (local i32)
+    (block
+      (loop
+        (set_local 0 (i32.const 1))
+        (set_local 0 (i32.mul (get_local 0) (i32.const 3)))
+        (set_local 0 (i32.sub (get_local 0) (i32.const 5)))
+        (set_local 0 (i32.mul (get_local 0) (i32.const 7)))
+        (br 1)
+        (set_local 0 (i32.mul (get_local 0) (i32.const 100)))
+      )
+    )
+    (i32.eq (get_local 0) (i32.const -14))
+  )
+
+  (func (export "while") (param i64) (result i64)
+    (local i64)
+    (set_local 1 (i64.const 1))
+    (block
+      (loop
+        (br_if 1 (i64.eqz (get_local 0)))
+        (set_local 1 (i64.mul (get_local 0) (get_local 1)))
+        (set_local 0 (i64.sub (get_local 0) (i64.const 1)))
+        (br 0)
+      )
+    )
+    (get_local 1)
+  )
+
+  (func (export "for") (param i64) (result i64)
+    (local i64 i64)
+    (set_local 1 (i64.const 1))
+    (set_local 2 (i64.const 2))
+    (block
+      (loop
+        (br_if 1 (i64.gt_u (get_local 2) (get_local 0)))
+        (set_local 1 (i64.mul (get_local 1) (get_local 2)))
+        (set_local 2 (i64.add (get_local 2) (i64.const 1)))
+        (br 0)
+      )
+    )
+    (get_local 1)
+  )
+
+  (func (export "nesting") (param f32 f32) (result f32)
+    (local f32 f32)
+    (block
+      (loop
+        (br_if 1 (f32.eq (get_local 0) (f32.const 0)))
+        (set_local 2 (get_local 1))
+        (block
+          (loop
+            (br_if 1 (f32.eq (get_local 2) (f32.const 0)))
+            (br_if 3 (f32.lt (get_local 2) (f32.const 0)))
+            (set_local 3 (f32.add (get_local 3) (get_local 2)))
+            (set_local 2 (f32.sub (get_local 2) (f32.const 2)))
+            (br 0)
+          )
+        )
+        (set_local 3 (f32.div (get_local 3) (get_local 0)))
+        (set_local 0 (f32.sub (get_local 0) (f32.const 1)))
+        (br 0)
+      )
+    )
+    (get_local 3)
+  )
+)
\ No newline at end of file