On Friday 04 July 2008 10:03:19 Joe Groff wrote:
> 20 { [ 1+ ] [ 1- ] [ 2^ ] } cleave
Hi Joe,
In some of my combinators which accept a sequence of quotations, if it finds a
word instead of a quotation, it is promoted to a quotation. So for example,
had I written 'cleave' this way, the above would look like this:
20 { 1+ 1- 2^ } cleave
I haven't been consistent with including this property in
sequence-of-quotation accepting combinators, mainly because it's an
experimental idea.
One word which acts like this is '<arr>' in combinators.cleave:
2 { 1+ 1- 2^ } <arr> .
{ 3 1 4 }
All combinators which accept a sequence of quotations could be endowed with
this. It's very trivial to support. Here's the implementation of '<arr>' :
MACRO: <arr> ( seq -- )
[ >quots ] [ length ] bi
'[ , cleave , narray ] ;
As you can see, supporting this feature involves a simple preprocessing of the
sequence, promoting words to 1quotations. Here's >quots:
: >quot ( obj -- quot ) dup word? [ 1quotation ] when ;
: >quots ( seq -- seq ) [ >quot ] map ;
Ed
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