1
2
3
4
5 package big
6
7 import (
8 "bytes"
9 "fmt"
10 "gob"
11 "testing"
12 )
13
14 var setStringTests = []struct {
15 in, out string
16 ok bool
17 }{
18 {"0", "0", true},
19 {"-0", "0", true},
20 {"1", "1", true},
21 {"-1", "-1", true},
22 {"1.", "1", true},
23 {"1e0", "1", true},
24 {"1.e1", "10", true},
25 {in: "1e", ok: false},
26 {in: "1.e", ok: false},
27 {in: "1e+14e-5", ok: false},
28 {in: "1e4.5", ok: false},
29 {in: "r", ok: false},
30 {in: "a/b", ok: false},
31 {in: "a.b", ok: false},
32 {"-0.1", "-1/10", true},
33 {"-.1", "-1/10", true},
34 {"2/4", "1/2", true},
35 {".25", "1/4", true},
36 {"-1/5", "-1/5", true},
37 {"8129567.7690E14", "812956776900000000000", true},
38 {"78189e+4", "781890000", true},
39 {"553019.8935e+8", "55301989350000", true},
40 {"98765432109876543210987654321e-10", "98765432109876543210987654321/10000000000", true},
41 {"9877861857500000E-7", "3951144743/4", true},
42 {"2169378.417e-3", "2169378417/1000000", true},
43 {"884243222337379604041632732738665534", "884243222337379604041632732738665534", true},
44 {"53/70893980658822810696", "53/70893980658822810696", true},
45 {"106/141787961317645621392", "53/70893980658822810696", true},
46 {"204211327800791583.81095", "4084226556015831676219/20000", true},
47 }
48
49 func TestRatSetString(t *testing.T) {
50 for i, test := range setStringTests {
51 x, ok := new(Rat).SetString(test.in)
52
53 if ok != test.ok || ok && x.RatString() != test.out {
54 t.Errorf("#%d got %s want %s", i, x.RatString(), test.out)
55 }
56 }
57 }
58
59 func TestRatScan(t *testing.T) {
60 var buf bytes.Buffer
61 for i, test := range setStringTests {
62 x := new(Rat)
63 buf.Reset()
64 buf.WriteString(test.in)
65
66 _, err := fmt.Fscanf(&buf, "%v", x)
67 if err == nil != test.ok {
68 if test.ok {
69 t.Errorf("#%d error: %s", i, err.String())
70 } else {
71 t.Errorf("#%d expected error", i)
72 }
73 continue
74 }
75 if err == nil && x.RatString() != test.out {
76 t.Errorf("#%d got %s want %s", i, x.RatString(), test.out)
77 }
78 }
79 }
80
81 var floatStringTests = []struct {
82 in string
83 prec int
84 out string
85 }{
86 {"0", 0, "0"},
87 {"0", 4, "0.0000"},
88 {"1", 0, "1"},
89 {"1", 2, "1.00"},
90 {"-1", 0, "-1"},
91 {".25", 2, "0.25"},
92 {".25", 1, "0.3"},
93 {".25", 3, "0.250"},
94 {"-1/3", 3, "-0.333"},
95 {"-2/3", 4, "-0.6667"},
96 {"0.96", 1, "1.0"},
97 {"0.999", 2, "1.00"},
98 {"0.9", 0, "1"},
99 {".25", -1, "0"},
100 {".55", -1, "1"},
101 }
102
103 func TestFloatString(t *testing.T) {
104 for i, test := range floatStringTests {
105 x, _ := new(Rat).SetString(test.in)
106
107 if x.FloatString(test.prec) != test.out {
108 t.Errorf("#%d got %s want %s", i, x.FloatString(test.prec), test.out)
109 }
110 }
111 }
112
113 func TestRatSign(t *testing.T) {
114 zero := NewRat(0, 1)
115 for _, a := range setStringTests {
116 var x Rat
117 x.SetString(a.in)
118 s := x.Sign()
119 e := x.Cmp(zero)
120 if s != e {
121 t.Errorf("got %d; want %d for z = %v", s, e, &x)
122 }
123 }
124 }
125
126 var ratCmpTests = []struct {
127 rat1, rat2 string
128 out int
129 }{
130 {"0", "0/1", 0},
131 {"1/1", "1", 0},
132 {"-1", "-2/2", 0},
133 {"1", "0", 1},
134 {"0/1", "1/1", -1},
135 {"-5/1434770811533343057144", "-5/1434770811533343057145", -1},
136 {"49832350382626108453/8964749413", "49832350382626108454/8964749413", -1},
137 {"-37414950961700930/7204075375675961", "37414950961700930/7204075375675961", -1},
138 {"37414950961700930/7204075375675961", "74829901923401860/14408150751351922", 0},
139 }
140
141 func TestRatCmp(t *testing.T) {
142 for i, test := range ratCmpTests {
143 x, _ := new(Rat).SetString(test.rat1)
144 y, _ := new(Rat).SetString(test.rat2)
145
146 out := x.Cmp(y)
147 if out != test.out {
148 t.Errorf("#%d got out = %v; want %v", i, out, test.out)
149 }
150 }
151 }
152
153 func TestIsInt(t *testing.T) {
154 one := NewInt(1)
155 for _, a := range setStringTests {
156 var x Rat
157 x.SetString(a.in)
158 i := x.IsInt()
159 e := x.Denom().Cmp(one) == 0
160 if i != e {
161 t.Errorf("got %v; want %v for z = %v", i, e, &x)
162 }
163 }
164 }
165
166 func TestRatAbs(t *testing.T) {
167 zero := NewRat(0, 1)
168 for _, a := range setStringTests {
169 var z Rat
170 z.SetString(a.in)
171 var e Rat
172 e.Set(&z)
173 if e.Cmp(zero) < 0 {
174 e.Sub(zero, &e)
175 }
176 z.Abs(&z)
177 if z.Cmp(&e) != 0 {
178 t.Errorf("got z = %v; want %v", &z, &e)
179 }
180 }
181 }
182
183 type ratBinFun func(z, x, y *Rat) *Rat
184 type ratBinArg struct {
185 x, y, z string
186 }
187
188 func testRatBin(t *testing.T, i int, name string, f ratBinFun, a ratBinArg) {
189 x, _ := NewRat(0, 1).SetString(a.x)
190 y, _ := NewRat(0, 1).SetString(a.y)
191 z, _ := NewRat(0, 1).SetString(a.z)
192 out := f(NewRat(0, 1), x, y)
193
194 if out.Cmp(z) != 0 {
195 t.Errorf("%s #%d got %s want %s", name, i, out, z)
196 }
197 }
198
199 var ratBinTests = []struct {
200 x, y string
201 sum, prod string
202 }{
203 {"0", "0", "0", "0"},
204 {"0", "1", "1", "0"},
205 {"-1", "0", "-1", "0"},
206 {"-1", "1", "0", "-1"},
207 {"1", "1", "2", "1"},
208 {"1/2", "1/2", "1", "1/4"},
209 {"1/4", "1/3", "7/12", "1/12"},
210 {"2/5", "-14/3", "-64/15", "-28/15"},
211 {"4707/49292519774798173060", "-3367/70976135186689855734", "84058377121001851123459/1749296273614329067191168098769082663020", "-1760941/388732505247628681598037355282018369560"},
212 {"-61204110018146728334/3", "-31052192278051565633/2", "-215564796870448153567/6", "950260896245257153059642991192710872711/3"},
213 {"-854857841473707320655/4237645934602118692642972629634714039", "-18/31750379913563777419", "-27/133467566250814981", "15387441146526731771790/134546868362786310073779084329032722548987800600710485341"},
214 {"618575745270541348005638912139/19198433543745179392300736", "-19948846211000086/637313996471", "27674141753240653/30123979153216", "-6169936206128396568797607742807090270137721977/6117715203873571641674006593837351328"},
215 {"-3/26206484091896184128", "5/2848423294177090248", "15310893822118706237/9330894968229805033368778458685147968", "-5/24882386581946146755650075889827061248"},
216 {"26946729/330400702820", "41563965/225583428284", "1238218672302860271/4658307703098666660055", "224002580204097/14906584649915733312176"},
217 {"-8259900599013409474/7", "-84829337473700364773/56707961321161574960", "-468402123685491748914621885145127724451/396955729248131024720", "350340947706464153265156004876107029701/198477864624065512360"},
218 {"575775209696864/1320203974639986246357", "29/712593081308", "410331716733912717985762465/940768218243776489278275419794956", "808/45524274987585732633"},
219 {"1786597389946320496771/2066653520653241", "6269770/1992362624741777", "3559549865190272133656109052308126637/4117523232840525481453983149257", "8967230/3296219033"},
220 {"-36459180403360509753/32150500941194292113930", "9381566963714/9633539", "301622077145533298008420642898530153/309723104686531919656937098270", "-3784609207827/3426986245"},
221 }
222
223 func TestRatBin(t *testing.T) {
224 for i, test := range ratBinTests {
225 arg := ratBinArg{test.x, test.y, test.sum}
226 testRatBin(t, i, "Add", (*Rat).Add, arg)
227
228 arg = ratBinArg{test.y, test.x, test.sum}
229 testRatBin(t, i, "Add symmetric", (*Rat).Add, arg)
230
231 arg = ratBinArg{test.sum, test.x, test.y}
232 testRatBin(t, i, "Sub", (*Rat).Sub, arg)
233
234 arg = ratBinArg{test.sum, test.y, test.x}
235 testRatBin(t, i, "Sub symmetric", (*Rat).Sub, arg)
236
237 arg = ratBinArg{test.x, test.y, test.prod}
238 testRatBin(t, i, "Mul", (*Rat).Mul, arg)
239
240 arg = ratBinArg{test.y, test.x, test.prod}
241 testRatBin(t, i, "Mul symmetric", (*Rat).Mul, arg)
242
243 if test.x != "0" {
244 arg = ratBinArg{test.prod, test.x, test.y}
245 testRatBin(t, i, "Quo", (*Rat).Quo, arg)
246 }
247
248 if test.y != "0" {
249 arg = ratBinArg{test.prod, test.y, test.x}
250 testRatBin(t, i, "Quo symmetric", (*Rat).Quo, arg)
251 }
252 }
253 }
254
255 func TestIssue820(t *testing.T) {
256 x := NewRat(3, 1)
257 y := NewRat(2, 1)
258 z := y.Quo(x, y)
259 q := NewRat(3, 2)
260 if z.Cmp(q) != 0 {
261 t.Errorf("got %s want %s", z, q)
262 }
263
264 y = NewRat(3, 1)
265 x = NewRat(2, 1)
266 z = y.Quo(x, y)
267 q = NewRat(2, 3)
268 if z.Cmp(q) != 0 {
269 t.Errorf("got %s want %s", z, q)
270 }
271
272 x = NewRat(3, 1)
273 z = x.Quo(x, x)
274 q = NewRat(3, 3)
275 if z.Cmp(q) != 0 {
276 t.Errorf("got %s want %s", z, q)
277 }
278 }
279
280 var setFrac64Tests = []struct {
281 a, b int64
282 out string
283 }{
284 {0, 1, "0"},
285 {0, -1, "0"},
286 {1, 1, "1"},
287 {-1, 1, "-1"},
288 {1, -1, "-1"},
289 {-1, -1, "1"},
290 {-9223372036854775808, -9223372036854775808, "1"},
291 }
292
293 func TestRatSetFrac64Rat(t *testing.T) {
294 for i, test := range setFrac64Tests {
295 x := new(Rat).SetFrac64(test.a, test.b)
296 if x.RatString() != test.out {
297 t.Errorf("#%d got %s want %s", i, x.RatString(), test.out)
298 }
299 }
300 }
301
302 func TestRatGobEncoding(t *testing.T) {
303 var medium bytes.Buffer
304 enc := gob.NewEncoder(&medium)
305 dec := gob.NewDecoder(&medium)
306 for i, test := range gobEncodingTests {
307 for j := 0; j < 4; j++ {
308 medium.Reset()
309 stest := test
310 if j&1 != 0 {
311
312 stest = "-" + test
313 }
314 if j%2 != 0 {
315
316 stest = stest + "." + test
317 }
318 var tx Rat
319 tx.SetString(stest)
320 if err := enc.Encode(&tx); err != nil {
321 t.Errorf("#%d%c: encoding failed: %s", i, 'a'+j, err)
322 }
323 var rx Rat
324 if err := dec.Decode(&rx); err != nil {
325 t.Errorf("#%d%c: decoding failed: %s", i, 'a'+j, err)
326 }
327 if rx.Cmp(&tx) != 0 {
328 t.Errorf("#%d%c: transmission failed: got %s want %s", i, 'a'+j, &rx, &tx)
329 }
330 }
331 }
332 }