# load-coroutine  generator x :: (1 2 3) { . yield } consume ; ' x start x x x x x x .n

# this is clearly because of consume:
# it messes with the abort stack...



# these should use only return stack recursion:
# move the control stuff to RS and leave the data stack free
# for unbalanced words to mess up

# in addition to that, they should not use the abort stack, which woul
# allow them to be used in coroutines (or anything that survives
# context switches)

# SEMANTICS: both are serial: they can use the data stack for
# accumulation: if map/consume are called with ( ..stuff.. lst xt ),
# the corresponding xt is called with ( ..stuf.. el )


# ( ..stuff.. ptr xt -- )
: _@map
       .S
       over if
              >r dup @ swap	# ( ..stuff.. in-el ptr )   ( xt )
	      r swap >r		# ( ..stuff.. in-el xt  )   ( ptr xt )
	      execute           # ( ..stuff.. out-el    )   ( ptr xt )
	      r !               # ( ..stuff.. )             ( ptr xt )
	      r> follow r>      # ( ..stuff.. next-ptr xt )
              pass _@map
       then
       2drop ;

: _@consume
       .S
       over if
              >r dup @ swap	# ( ..stuff.. in-el ptr )   ( xt )
	      r swap >r		# ( ..stuff.. in-el xt  )   ( ptr xt )
	      execute           # ( ..stuff.. out-el    )   ( ptr xt )
	      r> follow r>      # ( ..stuff.. next-ptr xt )
              pass _@consume
       then
       2drop ;

: _map     swap >r rsp head swap _@map r> ;
: _consume swap >r rsp head swap _@consume rdrop ;