;; RUN: wast --assert default --snapshot tests/snapshots % -f stack-switching
;; Simple pipes example
(module $pipes
(type $pfun (func (result i32)))
(type $cfun (func (param i32) (result i32)))
(type $producer (cont $pfun))
(type $consumer (cont $cfun))
(tag $send (export "send") (param i32))
(tag $receive (export "receive") (result i32))
(func $piper (export "pipe") (param $p (ref $producer)) (param $c (ref $consumer))
(local $n i32)
(local $consuming i32)
(local.set $n (i32.const -1))
(local.set $consuming (i32.const 1))
(loop $l
(if (local.get $consuming)
(then
(block $on-receive (result (ref $consumer))
(resume $consumer (on $receive $on-receive) (local.get $n) (local.get $c))
(return)
) ;; receive
(local.set $c)
(local.set $consuming (i32.const 0))
(br $l)
)
) ;; else producing
(block $on-send (result i32 (ref $producer))
(resume $producer (on $send $on-send) (local.get $p))
(return)
) ;; send
(local.set $p)
(local.set $n)
(local.set $consuming (i32.const 1))
(br $l)
)
)
)
(register "pipes")
(module
(type $pfun (func (result i32)))
(type $cfun (func (param i32) (result i32)))
(type $producer (cont $pfun))
(type $consumer (cont $cfun))
(tag $send (import "pipes" "send") (param i32))
(tag $receive (import "pipes" "receive") (result i32))
(func $pipe (import "pipes" "pipe") (param $p (ref $producer)) (param $c (ref $consumer)))
(func $log (import "spectest" "print_i32") (param i32))
(elem declare func $nats $sum)
;; send n, n+1, ...
(func $nats (param $n i32) (result i32)
(loop $l
(call $log (i32.const -1))
(call $log (local.get $n))
(suspend $send (local.get $n))
(local.set $n (i32.add (local.get $n) (i32.const 1)))
(br $l)
)
(unreachable)
)
;; receive 10 nats and return their sum
(func $sum (param $dummy i32) (result i32)
(local $i i32)
(local $a i32)
(local.set $i (i32.const 10))
(local.set $a (i32.const 0))
(loop $l
(local.set $a (i32.add (local.get $a) (suspend $receive)))
(call $log (i32.const -2))
(call $log (local.get $a))
(local.set $i (i32.sub (local.get $i) (i32.const 1)))
(br_if $l (i32.ne (local.get $i) (i32.const 0)))
)
(return (local.get $a))
)
(func (export "run") (param $n i32)
(call $pipe (cont.bind $consumer $producer (local.get $n) (cont.new $consumer (ref.func $nats)))
(cont.new $consumer (ref.func $sum))
)
)
)
(invoke "run" (i32.const 0))