WASI "Hello, World"

main.wat

(module
  (type $t0 (func (param i32 i32 i32 i32) (result i32)))
  (type $t1 (func))
  (import "wasi_unstable" "fd_write" (func $fd_write (type $t0)))
  (func $main (type $t1)
    i32.const 0
    i32.const 8
    i32.store
    i32.const 4
    i32.const 22
    i32.store
    i32.const 1
    i32.const 0
    i32.const 1
    i32.const 30
    call $fd_write
    drop
  )
  (memory $memory 1)
  (export "memory" (memory 0))
  (export "_start" (func $main))
  (data (i32.const 8) "My first WASI module!\0a")
)