"Here are some built-in combinators rewritten in terms of fried quotations:"\r
{ $table\r
{ { $link literalize } { $snippet ": literalize '[ _ ] ;" } }\r
- { { $link slip } { $snippet ": slip '[ @ _ ] call ;" } }\r
{ { $link curry } { $snippet ": curry '[ _ @ ] ;" } }\r
{ { $link compose } { $snippet ": compose '[ @ @ ] ;" } }\r
{ { $link bi@ } { $snippet ": bi@ tuck '[ _ @ _ @ ] call ;" } }\r
}\r
} ;\r
\r
-HELP: nslip\r
-{ $values { "n" integer } }\r
-{ $description "A generalization of " { $link slip } " that can work " \r
-"for any stack depth. The first " { $snippet "n" } " items after the quotation will be "\r
-"removed from the stack, the quotation called, and the items restored."\r
-} \r
-{ $examples\r
- { $example "USING: generalizations kernel prettyprint ;" "[ 99 ] 1 2 3 4 5 5 nslip 6 narray ." "{ 99 1 2 3 4 5 }" }\r
- "Some core words expressed in terms of " { $link nslip } ":"\r
- { $table\r
- { { $link slip } { $snippet "1 nslip" } }\r
- { { $link 2slip } { $snippet "2 nslip" } }\r
- { { $link 3slip } { $snippet "3 nslip" } }\r
- }\r
-} ;\r
-\r
HELP: nkeep\r
{ $values { "quot" quotation } { "n" integer } }\r
{ $description "A generalization of " { $link keep } " that can work " \r
\r
ARTICLE: "combinator-generalizations" "Generalized combinators"\r
{ $subsection ndip }\r
-{ $subsection nslip }\r
{ $subsection nkeep }\r
{ $subsection napply }\r
{ $subsection ncleave }\r
[ [ 1 ] 5 ndip ] must-infer\r
[ 1 2 3 4 ] [ 2 3 4 [ 1 ] 3 ndip ] unit-test\r
\r
-[ [ 99 ] 1 2 3 4 5 5 nslip ] must-infer\r
-{ 99 1 2 3 4 5 } [ [ 99 ] 1 2 3 4 5 5 nslip ] unit-test\r
[ 1 2 3 4 5 [ drop drop drop drop drop 2 ] 5 nkeep ] must-infer\r
{ 2 1 2 3 4 5 } [ 1 2 3 4 5 [ drop drop drop drop drop 2 ] 5 nkeep ] unit-test\r
[ [ 1 2 3 + ] ] [ 1 2 3 [ + ] 3 ncurry ] unit-test\r
MACRO: ndip ( quot n -- )
[ '[ _ dip ] ] times ;
-MACRO: nslip ( n -- )
- '[ [ call ] _ ndip ] ;
-
MACRO: nkeep ( quot n -- )
tuck '[ _ ndup _ _ ndip ] ;
": dip [ ] bi* ;"
": 2dip [ ] [ ] tri* ;"
""
- ": slip [ call ] [ ] bi* ;"
- ": 2slip [ call ] [ ] [ ] tri* ;"
- ""
": nip [ drop ] [ ] bi* ;"
": 2nip [ drop ] [ drop ] [ ] tri* ;"
""
{ $subsection both? }
{ $subsection either? } ;
-ARTICLE: "slip-keep-combinators" "Retain stack combinators"
+ARTICLE: "retainstack-combinators" "Retain stack combinators"
"Sometimes an additional storage area is needed to hold objects. The " { $emphasis "retain stack" } " is an auxilliary stack for this purpose. Objects can be moved between the data and retain stacks using a set of combinators."
$nl
"The dip combinators invoke the quotation at the top of the stack, hiding the values underneath:"
{ $subsection 2dip }
{ $subsection 3dip }
{ $subsection 4dip }
-"The slip combinators invoke a quotation further down on the stack. They are most useful for implementing other combinators:"
-{ $subsection slip }
-{ $subsection 2slip }
-{ $subsection 3slip }
"The keep combinators invoke a quotation which takes a number of values off the stack, and then they restore those values:"
{ $subsection keep }
{ $subsection 2keep }
ARTICLE: "dataflow-combinators" "Data flow combinators"
"Data flow combinators pass values between quotations:"
-{ $subsection "slip-keep-combinators" }
+{ $subsection "retainstack-combinators" }
{ $subsection "cleave-combinators" }
{ $subsection "spread-combinators" }
{ $subsection "apply-combinators" }
{ $description "Calls a quotation with an empty call stack. If the quotation returns, Factor will exit.." }
{ $notes "Used to implement " { $link "threads" } "." } ;
-HELP: slip
-{ $values { "quot" quotation } { "x" object } }
-{ $description "Calls a quotation while hiding the top of the stack." } ;
-
-HELP: 2slip
-{ $values { "quot" quotation } { "x" object } { "y" object } }
-{ $description "Calls a quotation while hiding the top two stack elements." } ;
-
-HELP: 3slip
-{ $values { "quot" quotation } { "x" object } { "y" object } { "z" object } }
-{ $description "Calls a quotation while hiding the top three stack elements." } ;
-
HELP: keep
{ $values { "quot" { $quotation "( x -- ... )" } } { "x" object } }
{ $description "Call a quotation with a value on the stack, restoring the value when the quotation returns." }
: ?if ( default cond true false -- )
pick [ drop [ drop ] 2dip call ] [ 2nip call ] if ; inline
-! Slippers and dippers.
+! Dippers.
! Not declared inline because the compiler special-cases them
-: slip ( quot x -- x )
- #! 'slip' and 'dip' can be defined in terms of each other
- #! because the JIT special-cases a 'dip' preceeded by
- #! a literal quotation.
- [ call ] dip ;
+: dip ( x quot -- x ) swap [ call ] dip ;
-: 2slip ( quot x y -- x y )
- #! '2slip' and '2dip' can be defined in terms of each other
- #! because the JIT special-cases a '2dip' preceeded by
- #! a literal quotation.
- [ call ] 2dip ;
+: 2dip ( x y quot -- x y ) -rot [ call ] 2dip ;
-: 3slip ( quot x y z -- x y z )
- #! '3slip' and '3dip' can be defined in terms of each other
- #! because the JIT special-cases a '3dip' preceeded by
- #! a literal quotation.
- [ call ] 3dip ;
-
-: dip ( x quot -- x ) swap slip ;
-
-: 2dip ( x y quot -- x y ) -rot 2slip ;
-
-: 3dip ( x y z quot -- x y z ) -roll 3slip ;
+: 3dip ( x y z quot -- x y z ) -roll [ call ] 3dip ;
: 4dip ( w x y z quot -- w x y z ) swap [ 3dip ] dip ; inline
! Keepers
-: keep ( x quot -- x ) over slip ; inline
+: keep ( x quot -- x ) over [ call ] dip ; inline
: 2keep ( x y quot -- x y ) [ 2dup ] dip 2dip ; inline
M: curry call uncurry call ;
-M: compose call uncompose slip call ;
+M: compose call uncompose [ call ] dip call ;
M: wrapper equal?
over wrapper? [ [ wrapped>> ] bi@ = ] [ 2drop f ] if ;
{ nkeep 5 }\r
{ npick 6 }\r
{ nrot 5 }\r
- { nslip 5 }\r
{ ntuck 6 }\r
{ nwith 4 }\r
{ over 2 }\r
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