Factor Cannot apply “call” to a run-time computed value
Factor Cannot apply “call” to a run-time computed value
I wanted to map over a nested array in factor so I created a helper function:
: nested-map ( a quote -- a' ) swap [ over map ] map nip ;
which i then called with
{ { 1 2 } { 3 4 } } [ 1 + ] nested-map
But when I call it I get the error from the title.
If I just paste the body of the function it works as intended:
{ { 1 2 } { 3 4 } } [ 1 + ] swap [ over map ] map nip
So I guess I have two questions: is there a better way to achieve the original goal, but also how am I supposed to create higher order functions without getting this error?
Thanks to johnb on the Factor's discord channel I got answers to these two questions:
In terms of nicer way to do a nested map nicely, fried quotations are the answer:
'[ _ map ] mapand in order to call a quotation inside a word definition, one needs to use
call( stack effect )form:: nested-map ( a quote -- a' ) '[ _ '[ _ call( x -- x' ) ] map ] map ;