/extra/taxes/usa/usa.factor

http://github.com/abeaumont/factor · Factor · 33 lines · 21 code · 9 blank · 3 comment · 1 complexity · 9431afe689caf9e1947c443db945b717 MD5 · raw file 

    

  1. ! Copyright (C) 2008 Doug Coleman.
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  2. ! See http://factorcode.org/license.txt for BSD license.
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  3. USING: accessors arrays assocs kernel math math.intervals
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  4. namespaces sequences money math.order taxes.usa.w4
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  5. taxes.usa.futa math.finance ;
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  6. IN: taxes.usa
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  8. ! Withhold: FICA, Medicare, Federal (FICA is social security)
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  9. 

  10. TUPLE: tax-table entity single married ;
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  11. C: <tax-table> tax-table
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  12. 

  13. GENERIC: adjust-allowances* ( salary w4 tax-table entity -- newsalary )
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  14. GENERIC: withholding* ( salary w4 tax-table entity -- x )
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  15. 

  16. : adjust-allowances ( salary w4 tax-table -- newsalary )
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  17.     dup entity>> adjust-allowances* ;
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  18. 

  19. : withholding ( salary w4 tax-table -- x )
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  20.     dup entity>> withholding* ;
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  21. 

  22. : tax-bracket-range ( pair -- n ) first2 swap - ;
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  23. 

  24. : tax-bracket ( tax salary triples -- tax salary )
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  25.     [ [ tax-bracket-range min ] keep third * + ] 2keep
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  26.     tax-bracket-range [-] ;
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  27. 

  28. : tax ( salary triples -- x )
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  29.     0 -rot [ tax-bracket ] each drop ;
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  30. 

  31. : marriage-table ( w4 tax-table -- triples )
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  32.     swap married?>>
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  33.     [ married>> ] [ single>> ] if ;
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