From 73df946d56c74384511a194dd01dbe099584fd1a Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 15:14:23 +0200 Subject: Adding upstream version 1.16.10. Signed-off-by: Daniel Baumann --- src/math/big/ratconv_test.go | 616 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 616 insertions(+) create mode 100644 src/math/big/ratconv_test.go (limited to 'src/math/big/ratconv_test.go') diff --git a/src/math/big/ratconv_test.go b/src/math/big/ratconv_test.go new file mode 100644 index 0000000..15d206c --- /dev/null +++ b/src/math/big/ratconv_test.go @@ -0,0 +1,616 @@ +// 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" + "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/"}, + + // 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 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) + } + } +} -- cgit v1.2.3