1 /// A few helper functions for manipulating English words. Extremely basic.
2 module arsd.english;
3
4 /++
5 Given a non-one `count` argument, will attempt to return the plural version of `word`. Only handles basic cases. If count is one, simply returns the word.
6
7 I originally wrote this for cases like `You have {n} {messages|plural(n)}` in web templates.
8 +/
9 string plural(int count, string word, string pluralWord = null) {
10 if(count == 1 || word.length == 0)
11 return word; // it isn't actually plural
12
13 if(pluralWord !is null)
14 return pluralWord;
15
16 switch(word[$ - 1]) {
17 case 's':
18 case 'a', 'e', 'i', 'o', 'u':
19 return word ~ "es";
20 case 'f':
21 return word[0 .. $-1] ~ "ves";
22 case 'y':
23 return word[0 .. $-1] ~ "ies";
24 default:
25 return word ~ "s";
26 }
27 }
28
29 /// Given an integer, tries to write out the long form number. For example, -5 becomes "negative five".
30 string numberToEnglish(long number) {
31 string word;
32 if(number == 0)
33 return "zero";
34
35 if(number < 0) {
36 word = "negative";
37 number = -number;
38 }
39
40 while(number) {
41 if(number < 100) {
42 if(number < singleWords.length) {
43 word ~= singleWords[cast(int) number];
44 break;
45 } else {
46 auto tens = number / 10;
47 word ~= tensPlaceWords[cast(int) tens];
48 number = number % 10;
49 if(number)
50 word ~= "-";
51 }
52 } else if(number < 1000) {
53 auto hundreds = number / 100;
54 word ~= onesPlaceWords[cast(int) hundreds] ~ " hundred";
55 number = number % 100;
56 if(number)
57 word ~= " and ";
58 } else if(number < 1000000) {
59 auto thousands = number / 1000;
60 word ~= numberToEnglish(thousands) ~ " thousand";
61 number = number % 1000;
62 if(number)
63 word ~= ", ";
64 } else if(number < 1_000_000_000) {
65 auto millions = number / 1000000;
66 word ~= numberToEnglish(millions) ~ " million";
67 number = number % 1000000;
68 if(number)
69 word ~= ", ";
70 } else if(number < 1_000_000_000_000) {
71 auto n = number / 1000000000;
72 word ~= numberToEnglish(n) ~ " billion";
73 number = number % 1000000000;
74 if(number)
75 word ~= ", ";
76 } else if(number < 1_000_000_000_000_000) {
77 auto n = number / 1000000000000;
78 word ~= numberToEnglish(n) ~ " trillion";
79 number = number % 1000000000000;
80 if(number)
81 word ~= ", ";
82 } else {
83 import std.conv;
84 return to!string(number);
85 }
86 }
87
88 return word;
89 }
90
91 unittest {
92 assert(numberToEnglish(1) == "one");
93 assert(numberToEnglish(5) == "five");
94 assert(numberToEnglish(13) == "thirteen");
95 assert(numberToEnglish(54) == "fifty-four");
96 assert(numberToEnglish(178) == "one hundred and seventy-eight");
97 assert(numberToEnglish(592) == "five hundred and ninety-two");
98 assert(numberToEnglish(1234) == "one thousand, two hundred and thirty-four");
99 assert(numberToEnglish(10234) == "ten thousand, two hundred and thirty-four");
100 assert(numberToEnglish(105234) == "one hundred and five thousand, two hundred and thirty-four");
101 }
102
103 enum onesPlaceWords = [
104 "zero",
105 "one",
106 "two",
107 "three",
108 "four",
109 "five",
110 "six",
111 "seven",
112 "eight",
113 "nine",
114 ];
115
116 enum singleWords = onesPlaceWords ~ [
117 "ten",
118 "eleven",
119 "twelve",
120 "thirteen",
121 "fourteen",
122 "fifteen",
123 "sixteen",
124 "seventeen",
125 "eighteen",
126 "nineteen",
127 ];
128
129 enum tensPlaceWords = [
130 null,
131 "ten",
132 "twenty",
133 "thirty",
134 "forty",
135 "fifty",
136 "sixty",
137 "seventy",
138 "eighty",
139 "ninety",
140 ];
141
142 /*
143 void main() {
144 import std.stdio;
145 foreach(i; 3433000 ..3433325)
146 writeln(numberToEnglish(i));
147 }
148 */
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