marine/examples/simple_greeting/wit

;; allocate function
(@interface type (func (param i32) (result i32)))

;; deallocate function
(@interface type (func (param i32 i32)))

;; greeting function
(@interface type (func (param string) (result string)))

;; strlen function
(@interface type (func (param string) (result i32)))

;; result extractor functions
(@interface type (func (result i32)))

(@interface export "allocate" (func  0))
(@interface export "deallocate" (func 1))
(@interface export "greeting" (func 2))
(@interface export "strlen" (func 3))
(@interface export "get_result_size" (func 4))
(@interface export "get_result_ptr" (func 4))

;; greeting export adapter
(@interface func (type 2)
    arg.get 0
    string.size
    call-core 0 ;; call allocate
    arg.get 0
    string.lower_memory
    call-core 2 ;; call greeting
    call-core 5 ;; call get_result_ptr
    call-core 4 ;; call get_result_size
    string.lift_memory
    call-core 5 ;; call get_result_ptr
    call-core 4 ;; call get_result_size
    call-core 1 ;; call deallocate
)

;; strlen export adapter
(@interface func (type 3)
    arg.get 0
    string.size
    call-core 0 ;; call allocate
    arg.get 0
    string.lower_memory
    call-core 3 ;; call strlen
)

;; Implementations
(@interface implement (func 2) (func 2))
(@interface implement (func 3) (func 3))