Editando: ratconv_test.go
// Copyright 2015 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package big import ( "bytes" "fmt" "io" "math" "reflect" "strconv" "strings" "testing" ) var exponentTests = []struct { s string // string to be scanned base2ok bool // true if 'p'/'P' exponents are accepted sepOk bool // true if '_' separators are accepted x int64 // expected exponent b int // expected exponent base err error // expected error next rune // next character (or 0, if at EOF) }{ // valid, without separators {"", false, false, 0, 10, nil, 0}, {"1", false, false, 0, 10, nil, '1'}, {"e0", false, false, 0, 10, nil, 0}, {"E1", false, false, 1, 10, nil, 0}, {"e+10", false, false, 10, 10, nil, 0}, {"e-10", false, false, -10, 10, nil, 0}, {"e123456789a", false, false, 123456789, 10, nil, 'a'}, {"p", false, false, 0, 10, nil, 'p'}, {"P+100", false, false, 0, 10, nil, 'P'}, {"p0", true, false, 0, 2, nil, 0}, {"P-123", true, false, -123, 2, nil, 0}, {"p+0a", true, false, 0, 2, nil, 'a'}, {"p+123__", true, false, 123, 2, nil, '_'}, // '_' is not part of the number anymore // valid, with separators {"e+1_0", false, true, 10, 10, nil, 0}, {"e-1_0", false, true, -10, 10, nil, 0}, {"e123_456_789a", false, true, 123456789, 10, nil, 'a'}, {"P+1_00", false, true, 0, 10, nil, 'P'}, {"p-1_2_3", true, true, -123, 2, nil, 0}, // invalid: no digits {"e", false, false, 0, 10, errNoDigits, 0}, {"ef", false, false, 0, 10, errNoDigits, 'f'}, {"e+", false, false, 0, 10, errNoDigits, 0}, {"E-x", false, false, 0, 10, errNoDigits, 'x'}, {"p", true, false, 0, 2, errNoDigits, 0}, {"P-", true, false, 0, 2, errNoDigits, 0}, {"p+e", true, false, 0, 2, errNoDigits, 'e'}, {"e+_x", false, true, 0, 10, errNoDigits, 'x'}, // invalid: incorrect use of separator {"e0_", false, true, 0, 10, errInvalSep, 0}, {"e_0", false, true, 0, 10, errInvalSep, 0}, {"e-1_2__3", false, true, -123, 10, errInvalSep, 0}, } func TestScanExponent(t *testing.T) { for _, a := range exponentTests { r := strings.NewReader(a.s) x, b, err := scanExponent(r, a.base2ok, a.sepOk) if err != a.err { t.Errorf("scanExponent%+v\n\tgot error = %v; want %v", a, err, a.err) } if x != a.x { t.Errorf("scanExponent%+v\n\tgot z = %v; want %v", a, x, a.x) } if b != a.b { t.Errorf("scanExponent%+v\n\tgot b = %d; want %d", a, b, a.b) } next, _, err := r.ReadRune() if err == io.EOF { next = 0 err = nil } if err == nil && next != a.next { t.Errorf("scanExponent%+v\n\tgot next = %q; want %q", a, next, a.next) } } } type StringTest struct { in, out string ok bool } var setStringTests = []StringTest{ // invalid {in: "1e"}, {in: "1.e"}, {in: "1e+14e-5"}, {in: "1e4.5"}, {in: "r"}, {in: "a/b"}, {in: "a.b"}, {in: "1/0"}, {in: "4/3/2"}, // issue 17001 {in: "4/3/"}, {in: "4/3."}, {in: "4/"}, {in: "13e-9223372036854775808"}, // CVE-2022-23772 // valid {"0", "0", true}, {"-0", "0", true}, {"1", "1", true}, {"-1", "-1", true}, {"1.", "1", true}, {"1e0", "1", true}, {"1.e1", "10", true}, {"-0.1", "-1/10", true}, {"-.1", "-1/10", true}, {"2/4", "1/2", true}, {".25", "1/4", true}, {"-1/5", "-1/5", true}, {"8129567.7690E14", "812956776900000000000", true}, {"78189e+4", "781890000", true}, {"553019.8935e+8", "55301989350000", true}, {"98765432109876543210987654321e-10", "98765432109876543210987654321/10000000000", true}, {"9877861857500000E-7", "3951144743/4", true}, {"2169378.417e-3", "2169378417/1000000", true}, {"884243222337379604041632732738665534", "884243222337379604041632732738665534", true}, {"53/70893980658822810696", "53/70893980658822810696", true}, {"106/141787961317645621392", "53/70893980658822810696", true}, {"204211327800791583.81095", "4084226556015831676219/20000", true}, {"0e9999999999", "0", true}, // issue #16176 } // These are not supported by fmt.Fscanf. var setStringTests2 = []StringTest{ // invalid {in: "4/3x"}, {in: "0/-1"}, {in: "-1/-1"}, // invalid with separators // (smoke tests only - a comprehensive set of tests is in natconv_test.go) {in: "10_/1"}, {in: "_10/1"}, {in: "1/1__0"}, // valid {"0b1000/3", "8/3", true}, {"0B1000/0x8", "1", true}, {"-010/1", "-8", true}, // 0-prefix indicates octal in this case {"-010.0", "-10", true}, {"-0o10/1", "-8", true}, {"0x10/1", "16", true}, {"0x10/0x20", "1/2", true}, {"0010", "10", true}, // 0-prefix is ignored in this case (not a fraction) {"0x10.0", "16", true}, {"0x1.8", "3/2", true}, {"0X1.8p4", "24", true}, {"0x1.1E2", "2289/2048", true}, // E is part of hex mantissa, not exponent {"0b1.1E2", "150", true}, {"0B1.1P3", "12", true}, {"0o10e-2", "2/25", true}, {"0O10p-3", "1", true}, // valid with separators // (smoke tests only - a comprehensive set of tests is in natconv_test.go) {"0b_1000/3", "8/3", true}, {"0B_10_00/0x8", "1", true}, {"0xdead/0B1101_1110_1010_1101", "1", true}, {"0B1101_1110_1010_1101/0XD_E_A_D", "1", true}, {"1_000.0", "1000", true}, {"0x_10.0", "16", true}, {"0x1_0.0", "16", true}, {"0x1.8_0", "3/2", true}, {"0X1.8p0_4", "24", true}, {"0b1.1_0E2", "150", true}, {"0o1_0e-2", "2/25", true}, {"0O_10p-3", "1", true}, } func TestRatSetString(t *testing.T) { var tests []StringTest tests = append(tests, setStringTests...) tests = append(tests, setStringTests2...) for i, test := range tests { x, ok := new(Rat).SetString(test.in) if ok { if !test.ok { t.Errorf("#%d SetString(%q) expected failure", i, test.in) } else if x.RatString() != test.out { t.Errorf("#%d SetString(%q) got %s want %s", i, test.in, x.RatString(), test.out) } } else { if test.ok { t.Errorf("#%d SetString(%q) expected success", i, test.in) } else if x != nil { t.Errorf("#%d SetString(%q) got %p want nil", i, test.in, x) } } } } func TestRatSetStringZero(t *testing.T) { got, _ := new(Rat).SetString("0") want := new(Rat).SetInt64(0) if !reflect.DeepEqual(got, want) { t.Errorf("got %#+v, want %#+v", got, want) } } func TestRatScan(t *testing.T) { var buf bytes.Buffer for i, test := range setStringTests { x := new(Rat) buf.Reset() buf.WriteString(test.in) _, err := fmt.Fscanf(&buf, "%v", x) if err == nil != test.ok { if test.ok { t.Errorf("#%d (%s) error: %s", i, test.in, err) } else { t.Errorf("#%d (%s) expected error", i, test.in) } continue } if err == nil && x.RatString() != test.out { t.Errorf("#%d got %s want %s", i, x.RatString(), test.out) } } } var floatStringTests = []struct { in string prec int out string }{ {"0", 0, "0"}, {"0", 4, "0.0000"}, {"1", 0, "1"}, {"1", 2, "1.00"}, {"-1", 0, "-1"}, {"0.05", 1, "0.1"}, {"-0.05", 1, "-0.1"}, {".25", 2, "0.25"}, {".25", 1, "0.3"}, {".25", 3, "0.250"}, {"-1/3", 3, "-0.333"}, {"-2/3", 4, "-0.6667"}, {"0.96", 1, "1.0"}, {"0.999", 2, "1.00"}, {"0.9", 0, "1"}, {".25", -1, "0"}, {".55", -1, "1"}, } func TestFloatString(t *testing.T) { for i, test := range floatStringTests { x, _ := new(Rat).SetString(test.in) if x.FloatString(test.prec) != test.out { t.Errorf("#%d got %s want %s", i, x.FloatString(test.prec), test.out) } } } // Test inputs to Rat.SetString. The prefix "long:" causes the test // to be skipped except in -long mode. (The threshold is about 500us.) var float64inputs = []string{ // Constants plundered from strconv/testfp.txt. // Table 1: Stress Inputs for Conversion to 53-bit Binary, < 1/2 ULP "5e+125", "69e+267", "999e-026", "7861e-034", "75569e-254", "928609e-261", "9210917e+080", "84863171e+114", "653777767e+273", "5232604057e-298", "27235667517e-109", "653532977297e-123", "3142213164987e-294", "46202199371337e-072", "231010996856685e-073", "9324754620109615e+212", "78459735791271921e+049", "272104041512242479e+200", "6802601037806061975e+198", "20505426358836677347e-221", "836168422905420598437e-234", "4891559871276714924261e+222", // Table 2: Stress Inputs for Conversion to 53-bit Binary, > 1/2 ULP "9e-265", "85e-037", "623e+100", "3571e+263", "81661e+153", "920657e-023", "4603285e-024", "87575437e-309", "245540327e+122", "6138508175e+120", "83356057653e+193", "619534293513e+124", "2335141086879e+218", "36167929443327e-159", "609610927149051e-255", "3743626360493413e-165", "94080055902682397e-242", "899810892172646163e+283", "7120190517612959703e+120", "25188282901709339043e-252", "308984926168550152811e-052", "6372891218502368041059e+064", // Table 14: Stress Inputs for Conversion to 24-bit Binary, <1/2 ULP "5e-20", "67e+14", "985e+15", "7693e-42", "55895e-16", "996622e-44", "7038531e-32", "60419369e-46", "702990899e-20", "6930161142e-48", "25933168707e+13", "596428896559e+20", // Table 15: Stress Inputs for Conversion to 24-bit Binary, >1/2 ULP "3e-23", "57e+18", "789e-35", "2539e-18", "76173e+28", "887745e-11", "5382571e-37", "82381273e-35", "750486563e-38", "3752432815e-39", "75224575729e-45", "459926601011e+15", // Constants plundered from strconv/atof_test.go. "0", "1", "+1", "1e23", "1E23", "100000000000000000000000", "1e-100", "123456700", "99999999999999974834176", "100000000000000000000001", "100000000000000008388608", "100000000000000016777215", "100000000000000016777216", "-1", "-0.1", "-0", // NB: exception made for this input "1e-20", "625e-3", // largest float64 "1.7976931348623157e308", "-1.7976931348623157e308", // next float64 - too large "1.7976931348623159e308", "-1.7976931348623159e308", // the border is ...158079 // borderline - okay "1.7976931348623158e308", "-1.7976931348623158e308", // borderline - too large "1.797693134862315808e308", "-1.797693134862315808e308", // a little too large "1e308", "2e308", "1e309", // way too large "1e310", "-1e310", "1e400", "-1e400", "long:1e400000", "long:-1e400000", // denormalized "1e-305", "1e-306", "1e-307", "1e-308", "1e-309", "1e-310", "1e-322", // smallest denormal "5e-324", "4e-324", "3e-324", // too small "2e-324", // way too small "1e-350", "long:1e-400000", // way too small, negative "-1e-350", "long:-1e-400000", // try to overflow exponent // [Disabled: too slow and memory-hungry with rationals.] // "1e-4294967296", // "1e+4294967296", // "1e-18446744073709551616", // "1e+18446744073709551616", // https://www.exploringbinary.com/java-hangs-when-converting-2-2250738585072012e-308/ "2.2250738585072012e-308", // https://www.exploringbinary.com/php-hangs-on-numeric-value-2-2250738585072011e-308/ "2.2250738585072011e-308", // A very large number (initially wrongly parsed by the fast algorithm). "4.630813248087435e+307", // A different kind of very large number. "22.222222222222222", "long:2." + strings.Repeat("2", 4000) + "e+1", // Exactly halfway between 1 and math.Nextafter(1, 2). // Round to even (down). "1.00000000000000011102230246251565404236316680908203125", // Slightly lower; still round down. "1.00000000000000011102230246251565404236316680908203124", // Slightly higher; round up. "1.00000000000000011102230246251565404236316680908203126", // Slightly higher, but you have to read all the way to the end. "long:1.00000000000000011102230246251565404236316680908203125" + strings.Repeat("0", 10000) + "1", // Smallest denormal, 2^(-1022-52) "4.940656458412465441765687928682213723651e-324", // Half of smallest denormal, 2^(-1022-53) "2.470328229206232720882843964341106861825e-324", // A little more than the exact half of smallest denormal // 2^-1075 + 2^-1100. (Rounds to 1p-1074.) "2.470328302827751011111470718709768633275e-324", // The exact halfway between smallest normal and largest denormal: // 2^-1022 - 2^-1075. (Rounds to 2^-1022.) "2.225073858507201136057409796709131975935e-308", "1152921504606846975", // 1<<60 - 1 "-1152921504606846975", // -(1<<60 - 1) "1152921504606846977", // 1<<60 + 1 "-1152921504606846977", // -(1<<60 + 1) "1/3", } // isFinite reports whether f represents a finite rational value. // It is equivalent to !math.IsNan(f) && !math.IsInf(f, 0). func isFinite(f float64) bool { return math.Abs(f) <= math.MaxFloat64 } func TestFloat32SpecialCases(t *testing.T) { for _, input := range float64inputs { if strings.HasPrefix(input, "long:") { if !*long { continue } input = input[len("long:"):] } r, ok := new(Rat).SetString(input) if !ok { t.Errorf("Rat.SetString(%q) failed", input) continue } f, exact := r.Float32() // 1. Check string -> Rat -> float32 conversions are // consistent with strconv.ParseFloat. // Skip this check if the input uses "a/b" rational syntax. if !strings.Contains(input, "/") { e64, _ := strconv.ParseFloat(input, 32) e := float32(e64) // Careful: negative Rats too small for // float64 become -0, but Rat obviously cannot // preserve the sign from SetString("-0"). switch { case math.Float32bits(e) == math.Float32bits(f): // Ok: bitwise equal. case f == 0 && r.Num().BitLen() == 0: // Ok: Rat(0) is equivalent to both +/- float64(0). default: t.Errorf("strconv.ParseFloat(%q) = %g (%b), want %g (%b); delta = %g", input, e, e, f, f, f-e) } } if !isFinite(float64(f)) { continue } // 2. Check f is best approximation to r. if !checkIsBestApprox32(t, f, r) { // Append context information. t.Errorf("(input was %q)", input) } // 3. Check f->R->f roundtrip is non-lossy. checkNonLossyRoundtrip32(t, f) // 4. Check exactness using slow algorithm. if wasExact := new(Rat).SetFloat64(float64(f)).Cmp(r) == 0; wasExact != exact { t.Errorf("Rat.SetString(%q).Float32().exact = %t, want %t", input, exact, wasExact) } } } func TestFloat64SpecialCases(t *testing.T) { for _, input := range float64inputs { if strings.HasPrefix(input, "long:") { if !*long { continue } input = input[len("long:"):] } r, ok := new(Rat).SetString(input) if !ok { t.Errorf("Rat.SetString(%q) failed", input) continue } f, exact := r.Float64() // 1. Check string -> Rat -> float64 conversions are // consistent with strconv.ParseFloat. // Skip this check if the input uses "a/b" rational syntax. if !strings.Contains(input, "/") { e, _ := strconv.ParseFloat(input, 64) // Careful: negative Rats too small for // float64 become -0, but Rat obviously cannot // preserve the sign from SetString("-0"). switch { case math.Float64bits(e) == math.Float64bits(f): // Ok: bitwise equal. case f == 0 && r.Num().BitLen() == 0: // Ok: Rat(0) is equivalent to both +/- float64(0). default: t.Errorf("strconv.ParseFloat(%q) = %g (%b), want %g (%b); delta = %g", input, e, e, f, f, f-e) } } if !isFinite(f) { continue } // 2. Check f is best approximation to r. if !checkIsBestApprox64(t, f, r) { // Append context information. t.Errorf("(input was %q)", input) } // 3. Check f->R->f roundtrip is non-lossy. checkNonLossyRoundtrip64(t, f) // 4. Check exactness using slow algorithm. if wasExact := new(Rat).SetFloat64(f).Cmp(r) == 0; wasExact != exact { t.Errorf("Rat.SetString(%q).Float64().exact = %t, want %t", input, exact, wasExact) } } } func TestIssue31184(t *testing.T) { var x Rat for _, want := range []string{ "-213.090", "8.192", "16.000", } { x.SetString(want) got := x.FloatString(3) if got != want { t.Errorf("got %s, want %s", got, want) } } } func TestIssue45910(t *testing.T) { var x Rat for _, test := range []struct { input string want bool }{ {"1e-1000001", false}, {"1e-1000000", true}, {"1e+1000000", true}, {"1e+1000001", false}, {"0p1000000000000", true}, {"1p-10000001", false}, {"1p-10000000", true}, {"1p+10000000", true}, {"1p+10000001", false}, {"1.770p02041010010011001001", false}, // test case from issue } { _, got := x.SetString(test.input) if got != test.want { t.Errorf("SetString(%s) got ok = %v; want %v", test.input, got, test.want) } } } func TestFloatPrec(t *testing.T) { var tests = []struct { f string prec int ok bool fdec string }{ // examples from the issue #50489 {"10/100", 1, true, "0.1"}, {"3/100", 2, true, "0.03"}, {"10", 0, true, "10"}, // more examples {"zero", 0, true, "0"}, // test uninitialized zero value for Rat {"0", 0, true, "0"}, // 0 {"1", 0, true, "1"}, // 1 {"1/2", 1, true, "0.5"}, // 0.5 {"1/3", 0, false, "0"}, // 0.(3) {"1/4", 2, true, "0.25"}, // 0.25 {"1/5", 1, true, "0.2"}, // 0.2 {"1/6", 1, false, "0.2"}, // 0.1(6) {"1/7", 0, false, "0"}, // 0.(142857) {"1/8", 3, true, "0.125"}, // 0.125 {"1/9", 0, false, "0"}, // 0.(1) {"1/10", 1, true, "0.1"}, // 0.1 {"1/11", 0, false, "0"}, // 0.(09) {"1/12", 2, false, "0.08"}, // 0.08(3) {"1/13", 0, false, "0"}, // 0.(076923) {"1/14", 1, false, "0.1"}, // 0.0(714285) {"1/15", 1, false, "0.1"}, // 0.0(6) {"1/16", 4, true, "0.0625"}, // 0.0625 {"10/2", 0, true, "5"}, // 5 {"10/3", 0, false, "3"}, // 3.(3) {"10/6", 0, false, "2"}, // 1.(6) {"1/10000000", 7, true, "0.0000001"}, // 0.0000001 {"1/3125", 5, true, "0.00032"}, // "0.00032" {"1/1024", 10, true, "0.0009765625"}, // 0.0009765625 {"1/304000", 7, false, "0.0000033"}, // 0.0000032(894736842105263157) {"1/48828125", 11, true, "0.00000002048"}, // 0.00000002048 } for _, test := range tests { var f Rat // check uninitialized zero value if test.f != "zero" { _, ok := f.SetString(test.f) if !ok { t.Fatalf("invalid test case: f = %s", test.f) } } // results for f and -f must be the same fdec := test.fdec for i := 0; i < 2; i++ { prec, ok := f.FloatPrec() if prec != test.prec || ok != test.ok { t.Errorf("%s: FloatPrec(%s): got prec, ok = %d, %v; want %d, %v", test.f, &f, prec, ok, test.prec, test.ok) } s := f.FloatString(test.prec) if s != fdec { t.Errorf("%s: FloatString(%s, %d): got %s; want %s", test.f, &f, prec, s, fdec) } // proceed with -f but don't add a "-" before a "0" if f.Sign() > 0 { f.Neg(&f) fdec = "-" + fdec } } } } func BenchmarkFloatPrecExact(b *testing.B) { for _, n := range []int{1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6} { // d := 5^n d := NewInt(5) p := NewInt(int64(n)) d.Exp(d, p, nil) // r := 1/d var r Rat r.SetFrac(NewInt(1), d) b.Run(fmt.Sprint(n), func(b *testing.B) { for i := 0; i < b.N; i++ { prec, ok := r.FloatPrec() if prec != n || !ok { b.Fatalf("got exact, ok = %d, %v; want %d, %v", prec, ok, uint64(n), true) } } }) } } func BenchmarkFloatPrecMixed(b *testing.B) { for _, n := range []int{1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6} { // d := (3·5·7·11)^n d := NewInt(3 * 5 * 7 * 11) p := NewInt(int64(n)) d.Exp(d, p, nil) // r := 1/d var r Rat r.SetFrac(NewInt(1), d) b.Run(fmt.Sprint(n), func(b *testing.B) { for i := 0; i < b.N; i++ { prec, ok := r.FloatPrec() if prec != n || ok { b.Fatalf("got exact, ok = %d, %v; want %d, %v", prec, ok, uint64(n), false) } } }) } } func BenchmarkFloatPrecInexact(b *testing.B) { for _, n := range []int{1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6} { // d := 5^n + 1 d := NewInt(5) p := NewInt(int64(n)) d.Exp(d, p, nil) d.Add(d, NewInt(1)) // r := 1/d var r Rat r.SetFrac(NewInt(1), d) b.Run(fmt.Sprint(n), func(b *testing.B) { for i := 0; i < b.N; i++ { _, ok := r.FloatPrec() if ok { b.Fatalf("got unexpected ok") } } }) } }
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