| // 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) |
| } |
| } |
| } |