{ t } [ 1 m 2 m 3 m 3array d-product 6 m^3 = ] unit-test
{ t } [ 3 m d-recip 1/3 { } { m } <dimensioned> = ] unit-test
+{ t } [ 2 m 3 d^ 2 m d-cube = ] unit-test
+
+{ t } [ 2 m 3 d^ 8 { m m m } { } <dimensioned> = ] unit-test
+{ t } [ 2 m -3 d^ 1/8 { } { m m m } <dimensioned> = ] unit-test
+{ t } [ 2 m 0 d^ 1 scalar = ] unit-test
+
: km/L ( n -- d ) km 1 L d/ ;
: mpg ( n -- d ) miles 1 gallons d/ ;
-USING: accessors arrays io kernel math namespaces splitting
-prettyprint sequences sorting vectors words inverse summary
-shuffle math.functions sets ;
+USING: accessors arrays combinators fry inverse kernel math
+math.functions sequences sets shuffle sorting splitting summary ;
IN: units
TUPLE: dimensioned value top bot ;
: d-sq ( d -- d ) dup d* ;
+: d-cube ( d -- d ) dup dup d* d* ;
+
: d-recip ( d -- d' )
>dimensioned< recip dimension-op> ;
: d/ ( d d -- d ) d-recip d* ;
+ERROR: dimensioned-power-op-expects-integer d n ;
+
+: d^ ( d n -- d^n )
+ dup integer? [ dimensioned-power-op-expects-integer ] unless
+ {
+ { [ dup 0 > ] [ 1 - over '[ _ d* ] times ] }
+ { [ dup 0 < ] [ 1 - abs over '[ _ d/ ] times ] }
+ { [ dup 0 = ] [ 2drop 1 scalar ] }
+ } cond ;
+
: comparison-op ( d d -- n n ) 2dup check-dimensions 2values ;
: d< ( d d -- ? ) comparison-op < ;