1 ! Copyright (c) 2007, 2008 Aaron Schaefer.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: combinators.short-circuit grouping kernel math math.parser namespaces
9 : small-numbers ( n -- str )
10 { "Zero" "One" "Two" "Three" "Four" "Five" "Six" "Seven" "Eight" "Nine"
11 "Ten" "Eleven" "Twelve" "Thirteen" "Fourteen" "Fifteen" "Sixteen"
12 "Seventeen" "Eighteen" "Nineteen" } nth ;
15 { f f "Twenty" "Thirty" "Forty" "Fifty" "Sixty" "Seventy" "Eighty" "Ninety" } nth ;
17 : scale-numbers ( n -- str ) ! up to 10^99
18 { f "Thousand" "Million" "Billion" "Trillion" "Quadrillion" "Quintillion"
19 "Sextillion" "Septillion" "Octillion" "Nonillion" "Decillion" "Undecillion"
20 "Duodecillion" "Tredecillion" "Quattuordecillion" "Quindecillion"
21 "Sexdecillion" "Septendecillion" "Octodecillion" "Novemdecillion"
22 "Vigintillion" "Unvigintillion" "Duovigintillion" "Trevigintillion"
23 "Quattuorvigintillion" "Quinvigintillion" "Sexvigintillion"
24 "Septvigintillion" "Octovigintillion" "Novemvigintillion" "Trigintillion"
25 "Untrigintillion" "Duotrigintillion" } nth ;
28 : set-conjunction ( seq -- )
29 first { [ dup 100 < ] [ dup 0 > ] } 0&& and-needed? set drop ;
31 : negative-text ( n -- str )
32 0 < "Negative " "" ? ;
34 : 3digit-groups ( n -- seq )
35 number>string <reversed> 3 <groups>
36 [ reverse string>number ] map ;
38 : hundreds-place ( n -- str )
39 100 /mod swap dup zero? [
42 small-numbers " Hundred" append
43 swap zero? [ " and " append ] unless
46 : tens-place ( n -- str )
49 dup zero? [ drop ] [ "-" swap small-numbers 3append ] if
51 dup zero? [ drop "" ] [ small-numbers ] if
54 : 3digits>text ( n -- str )
55 [ hundreds-place ] [ tens-place ] bi append ;
57 : text-with-scale ( index seq -- str )
58 [ nth 3digits>text ] [ drop scale-numbers ] 2bi
59 [ " " swap 3append ] unless-empty ;
61 : append-with-conjunction ( str1 str2 -- newstr )
65 and-needed? get " and " ", " ? rot 3append
69 : (recombine) ( str index seq -- newstr )
73 text-with-scale append-with-conjunction
76 : recombine ( seq -- str )
80 [ set-conjunction "" ] [ length ] [ ] tri
81 [ (recombine) ] curry each
84 : (number>text) ( n -- str )
85 [ negative-text ] [ abs 3digit-groups recombine ] bi append ;
89 : number>text ( n -- str )
90 dup zero? [ small-numbers ] [ [ (number>text) ] with-scope ] if ;