(module
 ;; import functions from env
 (func $close (import "env" "close") (param i32)         (result i32))
 (func $open  (import "env" "open")  (param i32 i32)     (result i32))
 (func $write (import "env" "write") (param i32 i32 i32) (result i32))
 (func $read  (import "env" "read")  (param i32 i32 i32) (result i32))

 (memory $mem 1)
 (data (i32.const 200) "data")
 (data (i32.const 230) "Hello, world!\n")

 (func $main (result i32)
       (local $fd i32)

       ;; open stdout
       (i32.const 200)
       (i32.const 42)
       (call $open)

       ;; set $fd to the file descriptor
       (set_local $fd)

       ;; write hello world
       (get_local $fd)
       (i32.const 230)
       (i32.const 14)
       (call $write)
       (drop)

       ;; close file
       (get_local $fd)
       (call $close)

       ;; open new file
       (i32.const 200)
       (i32.const 42)
       (call $open)

       ;; set $fd to the new file descriptor
       (set_local $fd)

       ;; read hello world
       (get_local $fd)
       (i32.const 255)
       (i32.const 14)
       (call $read)
       (drop)

       ;; return 0
       )
 (export "main" (func $main)))