factor/contrib/units/dimensioned.factor

95 lines
2.4 KiB
Factor

USING: kernel prettyprint io sequences words lists vectors inspector math errors namespaces ;
IN: units-internal
: seq-intersect ( seq1 seq2 -- seq1/\seq2 )
[ swap member? ] subset-with ; flushable
: 2list ( x y -- [ x y ] ) f cons cons ;
IN: units
TUPLE: dimensioned val top bot ;
C: dimensioned
[ set-dimensioned-bot ] keep
[ set-dimensioned-top ] keep
over number? [ "dimensioned must be a number" throw ] unless
[ set-dimensioned-val ] keep ;
: remove-one ( obj seq -- seq )
[ index ] keep over -1 = [
2drop
] [
[ 0 -rot <slice> ] 2keep
>r 1+ r> [ length ] keep <slice> append
] if ;
: dimensions ( dimensioned -- top bot )
dup >r dimensioned-top r> dimensioned-bot ;
: 2remove-one ( obj seq seq -- seq seq )
pick swap remove-one >r remove-one r> ;
: symbolic-reduce ( seq seq -- seq seq )
[ seq-intersect ] 2keep rot dup empty? [
drop
] [
first -rot 2remove-one symbolic-reduce
] if ;
: reduce-units ( dimensioned -- )
dup dimensions symbolic-reduce pick set-dimensioned-bot swap set-dimensioned-top ;
: 2reduce-units ( d d -- )
>r dup reduce-units r> dup reduce-units ;
: 2val ( d d -- )
[ dimensioned-val ] 2apply ;
: =units?
>r dimensions 2list r> dimensions 2list = ;
: d+ ( d d -- )
2dup =units? [
"d+: dimensions must be the same" throw
] unless
dup dimensions
>r >r 2val + r> r> <dimensioned> ;
: d- ( d d -- )
2dup =units? [
"d-: dimensions must be the same" throw
] unless
dup dimensions
>r >r 2val - r> r> <dimensioned> ;
: add-dimensions ( d d -- d )
>r dimensions r> dimensions >r swap >r append r> r> append 0 -rot <dimensioned> ;
: (d*)
>r add-dimensions r> over set-dimensioned-val dup reduce-units ;
: d* ( d d -- )
2dup 2val * (d*) ;
: swap-dimensions ( d -- d )
dup dimensions rot [ set-dimensioned-top ] keep [ set-dimensioned-bot ] keep ;
: d/ ( d d -- )
swap-dimensions 2dup 2val / (d*) ;
: d-inv ( d -- d )
swap-dimensions dup dimensioned-val 1 swap / over set-dimensioned-val ;
: d-product ( v -- d ) 1 { } { } <dimensioned> [ d* ] reduce ;
! does not compile
! Example: 4 m { km } { } convert
: convert ( d top bot -- val )
>r [ [ 1 swap execute , ] each ] { } make d-product r>
[ [ 1 swap execute d-inv , ] each ] { } make d-product
d*
2dup =units? [ "cannot make that conversion" throw ] unless
2val / ;