WAREKI.FS Data-Driven Refactor

\ wareki.fs - Display WAREKI and Anno Domini corresponding years
\ +JMJ 2020 David Meyer 
\ 2020/3/31 Add Reiwa era

\ help-wareki - Display module help
: help-wareki ( -- )
    cr ." WAREKI" cr
    ." Display Japanese era years corresponding to A.D. years and" cr
    ." vice versa." cr
    ." HEISEI ( u -- ) Display A.D. year corresponding to Heisei era year." cr
    ." MEIJI ( u -- ) Display A.D. year corresponding to Meiji era year." cr
    ." NENGO ( u -- ) Display Japanese year in Meiji, Taishou, Shouwa," cr
    ."                Heisei, or Reiwa eras corresponding to A.D. year." cr
    ." REIWA ( u -- ) Display A.D. year corresponding to Reiwa era year." cr
    ." SHOWA ( u -- ) Display A.D. year corresponding to Shouwa era year." cr
    ." TAISHO ( u -- ) Display A.D. year corresponding to Taishou era year." cr
;

\ nengo - Display NENGO for A.D. (Meiji, Taishou, Shouwa,
\         Heisei, Reiwa eras only)
: nengo ( u -- )
    dup 1868 < if
	." ERROR: Year precedes MEIJI era " drop
    else
	dup 1868 = if
	    ." MEIJI GANNEN (Sep 8 -) " drop
	else
	    dup 1912 < if
		." MEIJI " 1867 - .
	    else
		dup 1912 = if
		    ." MEIJI 45/TAISHO GANNEN (Jul 30-) " drop
		else
		    dup 1926 < if
			." TAISHO " 1911 - .
		    else
			dup 1926 = if
			    ." TAISHO 15/SHOWA GANNEN (Dec 25-) " drop
			else
			    dup 1989 < if
				." SHOWA " 1925 - .
			    else
				dup 1989 = if
				    ." SHOWA 64/HEISEI GANNEN (Jan 8-) " drop
				else
                                    dup 2019 < if
                                        ." HEISEI " 1988 - .
                                    else
                                        dup 2019 = if
                                            ." HEISEI 31/REIWA GANNEN (May 1-) " drop                        
                                        else
                                            ." REIWA " 2018 - .
                                        then
                                    then
				then
			    then
			then
		    then
		then
	    then
	then
    then
;

\ meiji - Display A.D. for Meiji era NENGO.
: meiji ( u -- )
    dup 0= if
	." ERROR: NENGO < 1 " drop
    else
	dup 45 > if
	    ." ERROR: NENGO > 45 " drop
	else
	    ." AD " 1867 + .
	then
    then
;

\ taisho - Display A.D. for Taishou era NENGO.
: taisho ( u -- )
    dup 0= if
	." ERROR: NENGO < 1 " drop
    else
	dup 15 > if
	    ." ERROR: NENGO > 15 " drop
	else
	    ." AD " 1911 + .
	then
    then
;

\ showa - Display A.D. for Shouwa era NENGO.
: showa ( u -- )
    dup 0= if
	." ERROR: NENGO < 1 " drop
    else
	dup 64 > if
	    ." ERROR: NENGO > 64 " drop
	else
	    ." AD " 1925 + .
	then
    then
;

\ heisei - Display A.D. for Heisei era NENGO.
: heisei ( u -- )
    dup 0= if
	." ERROR: NENGO < 1 " drop
    else
	." AD " 1988 + .
    then
;

\ reiwa - Display A.D. for Reiwa era NENGO.
: reiwa ( u -- )
    dup 0= if
        ." ERROR: NENGO < 1 " drop
    else
        ." AD " 2018 + .
    then
;

cr ." Type 'help-wareki' for help" 
		
\ wareki.fs - Display WAREKI and Anno Domini corresponding years
\ +JMJ 2022 David Meyer 
\ 2020/3/31 Add Reiwa era
\ 2022/2/9 Refactor and convert to data-driven

\ help-wareki - Display module help
: help-wareki ( -- )
    cr ." WAREKI" cr
    ." Display Japanese era years corresponding to A.D. years and" cr
    ." vice versa." cr
    ." HEISEI ( u -- ) Display A.D. year corresponding to Heisei era year." cr
    ." MEIJI ( u -- ) Display A.D. year corresponding to Meiji era year." cr
    ." NENGO ( u -- ) Display Japanese year in Meiji, Taishou, Shouwa," cr
    ."                Heisei, or Reiwa eras corresponding to A.D. year." cr
    ." REIWA ( u -- ) Display A.D. year corresponding to Reiwa era year." cr
    ." SHOWA ( u -- ) Display A.D. year corresponding to Shouwa era year." cr
    ." TAISHO ( u -- ) Display A.D. year corresponding to Taishou era year." cr
;

0 constant ERAM  \ MEIJI era index
1 constant ERAT  \ TAISHO era index
2 constant ERAS  \ SHOWA era index
3 constant ERAH  \ HEISEI era index
4 constant ERAR  \ REIWA era index

create ERALFGY  \ Era last full Gregorian year (M/T/S/H/R)
1867 , 1911 , 1925 , 1988 , 2018 ,
create ERALYR  \ Era last year (M/T/S/H)
45 , 15 , 64 , 31 ,

create ERANAME  \ Era name length/string (M/T/S/H/R)
5 , 77 c, 69 c, 73 c, 74 c, 73 c, 0 c,   \ "MEIJI"
6 , 84 c, 65 c, 73 c, 83 c, 72 c, 79 c,  \ "TAISHO"
5 , 83 c, 72 c, 79 c, 87 c, 65 c, 0 c,   \ "SHOWA"
6 , 72 c, 69 c, 73 c, 83 c, 69 c, 73 c,  \ "HEISEI"
5 , 82 c, 69 c, 73 c, 87 c, 65 c, 0 c,   \ "REIWA"

create ERADATE  \ Era start date length/string (M/T/S/H/R)
5 , 83 c, 101 c, 112 c, 32 c, 56 c, 0 c,   \ "Sep 8"
6 , 74 c, 117 c, 108 c, 32 c, 51 c, 48 c,  \ "Jul 30"
6 , 68 c, 101 c, 99 c, 32 c, 50 c, 53 c,   \ "Dec 25"
5 , 74 c, 97 c, 110 c, 32 c, 56 c, 0 c,    \ "Jan 8"
5 , 77 c, 97 c, 121 c, 32 c, 49 c, 0 c,    \ "May 1"

: []@ ( uidx a-base -- a-addr ) swap cells + @ ;

: []$ ( uidx a-base -- c-addr ulen )
    swap 1 cells 6 chars + * + dup 1 cells + swap @
;

: ng>gy ( ungy uera -- ugy ) ERALFGY []@ + ;

: gy>ng ( ugy -- ungy uera )
    ERAR begin
	dup ERALFGY []@ rot dup rot <= while swap 1-
    repeat
    over ERALFGY []@ - swap
;

: prera ( uera -- ) ERANAME []$ type space ;

: preradt ( uera -- ) ERADATE []$ type ;

: prgy ( ug -- ) ." AD " . ;

: ngyok? ( uera ungy -- f )
    dup 0< if
	2drop false else
	swap ERALYR []@ 1+ > if false else true then
    then
;

: nengo ( ugy -- )
    dup ERAM ERALFGY []@ <= if
	drop ." Year prior to MEIJI era unsupported " else
	gy>ng over 1 = if
	    dup 1- dup prera ERALYR []@ . ." / "
	    dup prera ." GANNEN (" preradt ." -) " drop else
	    prera . then
	then
;

: cvtng ( ungy uera -- )
    2dup swap ngyok? if
	ng>gy prgy else
	2drop ." Invalid NENGO year " then
;

: meiji ( ungy -- ) ERAM cvtng ;
: taisho ( ungy -- ) ERAT cvtng ;
: showa ( ungy -- ) ERAS cvtng ;
: heisei ( ungy -- ) ERAH cvtng ;
: reiwa ( ungy -- ) ERAR cvtng ;

cr ." Type 'help-wareki' for help"