Hello,
For these combinators: map each map-with each-with
it's possible to write a single "smart" combinator which figures out which one
of those to call. Each of those combinators takes a quotation. The effect of
the quotation is different for each of those combinators. So all the "super
combinator" has to do is infer the effect and call the appropriate one. The
implementation is below. I called it 'for'. Examples:
{ 1 2 3 4 } [ 1+ ] for ! map
10 { 1 2 3 4 } [ + ] for ! map-with
{ 1 2 3 4 } [ drop ] for ! each
10 { 1 2 3 4 } [ 2drop ] for ! each-with
The quotation has to be inferable in order for 'for' to work.
Ed
USING: kernel effects inference combinators sequences inference.transforms ;
IN: for
: do-map? ( quot -- quot ? ) dup infer nip T{ effect f 1 1 f } equal? ;
: do-each? ( quot -- quot ? ) dup infer nip T{ effect f 1 0 f } equal? ;
: do-map-with? ( quot -- quot ? ) dup infer nip T{ effect f 2 1 f } equal? ;
: do-each-with? ( quot -- quot ? ) dup infer nip T{ effect f 2 0 f } equal? ;
: [for] ( seq quot -- quot )
{ { [ do-map? ] [ [ map ] ] }
{ [ do-each? ] [ [ each ] ] }
{ [ do-map-with? ] [ [ map-with ] ] }
{ [ do-each-with? ] [ [ each-with ] ] } }
cond ;
: for ( seq quot -- ) [for] call ;
\ for 1 [ [for] ] define-transform
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