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authorMatthew Heon <matthew.heon@gmail.com>2017-11-01 11:24:59 -0400
committerMatthew Heon <matthew.heon@gmail.com>2017-11-01 11:24:59 -0400
commita031b83a09a8628435317a03f199cdc18b78262f (patch)
treebc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/github.com/pquerna/ffjson/fflib/v1/internal
parent2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff)
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Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/github.com/pquerna/ffjson/fflib/v1/internal')
-rw-r--r--vendor/github.com/pquerna/ffjson/fflib/v1/internal/atof.go936
-rw-r--r--vendor/github.com/pquerna/ffjson/fflib/v1/internal/atoi.go213
-rw-r--r--vendor/github.com/pquerna/ffjson/fflib/v1/internal/extfloat.go668
-rw-r--r--vendor/github.com/pquerna/ffjson/fflib/v1/internal/ftoa.go475
4 files changed, 2292 insertions, 0 deletions
diff --git a/vendor/github.com/pquerna/ffjson/fflib/v1/internal/atof.go b/vendor/github.com/pquerna/ffjson/fflib/v1/internal/atof.go
new file mode 100644
index 000000000..46c1289ec
--- /dev/null
+++ b/vendor/github.com/pquerna/ffjson/fflib/v1/internal/atof.go
@@ -0,0 +1,936 @@
+/**
+ * Copyright 2014 Paul Querna
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+/* Portions of this file are on Go stdlib's strconv/atof.go */
+
+// Copyright 2009 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 internal
+
+// decimal to binary floating point conversion.
+// Algorithm:
+// 1) Store input in multiprecision decimal.
+// 2) Multiply/divide decimal by powers of two until in range [0.5, 1)
+// 3) Multiply by 2^precision and round to get mantissa.
+
+import "math"
+
+var optimize = true // can change for testing
+
+func equalIgnoreCase(s1 []byte, s2 []byte) bool {
+ if len(s1) != len(s2) {
+ return false
+ }
+ for i := 0; i < len(s1); i++ {
+ c1 := s1[i]
+ if 'A' <= c1 && c1 <= 'Z' {
+ c1 += 'a' - 'A'
+ }
+ c2 := s2[i]
+ if 'A' <= c2 && c2 <= 'Z' {
+ c2 += 'a' - 'A'
+ }
+ if c1 != c2 {
+ return false
+ }
+ }
+ return true
+}
+
+func special(s []byte) (f float64, ok bool) {
+ if len(s) == 0 {
+ return
+ }
+ switch s[0] {
+ default:
+ return
+ case '+':
+ if equalIgnoreCase(s, []byte("+inf")) || equalIgnoreCase(s, []byte("+infinity")) {
+ return math.Inf(1), true
+ }
+ case '-':
+ if equalIgnoreCase(s, []byte("-inf")) || equalIgnoreCase(s, []byte("-infinity")) {
+ return math.Inf(-1), true
+ }
+ case 'n', 'N':
+ if equalIgnoreCase(s, []byte("nan")) {
+ return math.NaN(), true
+ }
+ case 'i', 'I':
+ if equalIgnoreCase(s, []byte("inf")) || equalIgnoreCase(s, []byte("infinity")) {
+ return math.Inf(1), true
+ }
+ }
+ return
+}
+
+func (b *decimal) set(s []byte) (ok bool) {
+ i := 0
+ b.neg = false
+ b.trunc = false
+
+ // optional sign
+ if i >= len(s) {
+ return
+ }
+ switch {
+ case s[i] == '+':
+ i++
+ case s[i] == '-':
+ b.neg = true
+ i++
+ }
+
+ // digits
+ sawdot := false
+ sawdigits := false
+ for ; i < len(s); i++ {
+ switch {
+ case s[i] == '.':
+ if sawdot {
+ return
+ }
+ sawdot = true
+ b.dp = b.nd
+ continue
+
+ case '0' <= s[i] && s[i] <= '9':
+ sawdigits = true
+ if s[i] == '0' && b.nd == 0 { // ignore leading zeros
+ b.dp--
+ continue
+ }
+ if b.nd < len(b.d) {
+ b.d[b.nd] = s[i]
+ b.nd++
+ } else if s[i] != '0' {
+ b.trunc = true
+ }
+ continue
+ }
+ break
+ }
+ if !sawdigits {
+ return
+ }
+ if !sawdot {
+ b.dp = b.nd
+ }
+
+ // optional exponent moves decimal point.
+ // if we read a very large, very long number,
+ // just be sure to move the decimal point by
+ // a lot (say, 100000). it doesn't matter if it's
+ // not the exact number.
+ if i < len(s) && (s[i] == 'e' || s[i] == 'E') {
+ i++
+ if i >= len(s) {
+ return
+ }
+ esign := 1
+ if s[i] == '+' {
+ i++
+ } else if s[i] == '-' {
+ i++
+ esign = -1
+ }
+ if i >= len(s) || s[i] < '0' || s[i] > '9' {
+ return
+ }
+ e := 0
+ for ; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
+ if e < 10000 {
+ e = e*10 + int(s[i]) - '0'
+ }
+ }
+ b.dp += e * esign
+ }
+
+ if i != len(s) {
+ return
+ }
+
+ ok = true
+ return
+}
+
+// readFloat reads a decimal mantissa and exponent from a float
+// string representation. It sets ok to false if the number could
+// not fit return types or is invalid.
+func readFloat(s []byte) (mantissa uint64, exp int, neg, trunc, ok bool) {
+ const uint64digits = 19
+ i := 0
+
+ // optional sign
+ if i >= len(s) {
+ return
+ }
+ switch {
+ case s[i] == '+':
+ i++
+ case s[i] == '-':
+ neg = true
+ i++
+ }
+
+ // digits
+ sawdot := false
+ sawdigits := false
+ nd := 0
+ ndMant := 0
+ dp := 0
+ for ; i < len(s); i++ {
+ switch c := s[i]; true {
+ case c == '.':
+ if sawdot {
+ return
+ }
+ sawdot = true
+ dp = nd
+ continue
+
+ case '0' <= c && c <= '9':
+ sawdigits = true
+ if c == '0' && nd == 0 { // ignore leading zeros
+ dp--
+ continue
+ }
+ nd++
+ if ndMant < uint64digits {
+ mantissa *= 10
+ mantissa += uint64(c - '0')
+ ndMant++
+ } else if s[i] != '0' {
+ trunc = true
+ }
+ continue
+ }
+ break
+ }
+ if !sawdigits {
+ return
+ }
+ if !sawdot {
+ dp = nd
+ }
+
+ // optional exponent moves decimal point.
+ // if we read a very large, very long number,
+ // just be sure to move the decimal point by
+ // a lot (say, 100000). it doesn't matter if it's
+ // not the exact number.
+ if i < len(s) && (s[i] == 'e' || s[i] == 'E') {
+ i++
+ if i >= len(s) {
+ return
+ }
+ esign := 1
+ if s[i] == '+' {
+ i++
+ } else if s[i] == '-' {
+ i++
+ esign = -1
+ }
+ if i >= len(s) || s[i] < '0' || s[i] > '9' {
+ return
+ }
+ e := 0
+ for ; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
+ if e < 10000 {
+ e = e*10 + int(s[i]) - '0'
+ }
+ }
+ dp += e * esign
+ }
+
+ if i != len(s) {
+ return
+ }
+
+ exp = dp - ndMant
+ ok = true
+ return
+
+}
+
+// decimal power of ten to binary power of two.
+var powtab = []int{1, 3, 6, 9, 13, 16, 19, 23, 26}
+
+func (d *decimal) floatBits(flt *floatInfo) (b uint64, overflow bool) {
+ var exp int
+ var mant uint64
+
+ // Zero is always a special case.
+ if d.nd == 0 {
+ mant = 0
+ exp = flt.bias
+ goto out
+ }
+
+ // Obvious overflow/underflow.
+ // These bounds are for 64-bit floats.
+ // Will have to change if we want to support 80-bit floats in the future.
+ if d.dp > 310 {
+ goto overflow
+ }
+ if d.dp < -330 {
+ // zero
+ mant = 0
+ exp = flt.bias
+ goto out
+ }
+
+ // Scale by powers of two until in range [0.5, 1.0)
+ exp = 0
+ for d.dp > 0 {
+ var n int
+ if d.dp >= len(powtab) {
+ n = 27
+ } else {
+ n = powtab[d.dp]
+ }
+ d.Shift(-n)
+ exp += n
+ }
+ for d.dp < 0 || d.dp == 0 && d.d[0] < '5' {
+ var n int
+ if -d.dp >= len(powtab) {
+ n = 27
+ } else {
+ n = powtab[-d.dp]
+ }
+ d.Shift(n)
+ exp -= n
+ }
+
+ // Our range is [0.5,1) but floating point range is [1,2).
+ exp--
+
+ // Minimum representable exponent is flt.bias+1.
+ // If the exponent is smaller, move it up and
+ // adjust d accordingly.
+ if exp < flt.bias+1 {
+ n := flt.bias + 1 - exp
+ d.Shift(-n)
+ exp += n
+ }
+
+ if exp-flt.bias >= 1<<flt.expbits-1 {
+ goto overflow
+ }
+
+ // Extract 1+flt.mantbits bits.
+ d.Shift(int(1 + flt.mantbits))
+ mant = d.RoundedInteger()
+
+ // Rounding might have added a bit; shift down.
+ if mant == 2<<flt.mantbits {
+ mant >>= 1
+ exp++
+ if exp-flt.bias >= 1<<flt.expbits-1 {
+ goto overflow
+ }
+ }
+
+ // Denormalized?
+ if mant&(1<<flt.mantbits) == 0 {
+ exp = flt.bias
+ }
+ goto out
+
+overflow:
+ // ±Inf
+ mant = 0
+ exp = 1<<flt.expbits - 1 + flt.bias
+ overflow = true
+
+out:
+ // Assemble bits.
+ bits := mant & (uint64(1)<<flt.mantbits - 1)
+ bits |= uint64((exp-flt.bias)&(1<<flt.expbits-1)) << flt.mantbits
+ if d.neg {
+ bits |= 1 << flt.mantbits << flt.expbits
+ }
+ return bits, overflow
+}
+
+// Exact powers of 10.
+var float64pow10 = []float64{
+ 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
+ 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
+ 1e20, 1e21, 1e22,
+}
+var float32pow10 = []float32{1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, 1e10}
+
+// If possible to convert decimal representation to 64-bit float f exactly,
+// entirely in floating-point math, do so, avoiding the expense of decimalToFloatBits.
+// Three common cases:
+// value is exact integer
+// value is exact integer * exact power of ten
+// value is exact integer / exact power of ten
+// These all produce potentially inexact but correctly rounded answers.
+func atof64exact(mantissa uint64, exp int, neg bool) (f float64, ok bool) {
+ if mantissa>>float64info.mantbits != 0 {
+ return
+ }
+ f = float64(mantissa)
+ if neg {
+ f = -f
+ }
+ switch {
+ case exp == 0:
+ // an integer.
+ return f, true
+ // Exact integers are <= 10^15.
+ // Exact powers of ten are <= 10^22.
+ case exp > 0 && exp <= 15+22: // int * 10^k
+ // If exponent is big but number of digits is not,
+ // can move a few zeros into the integer part.
+ if exp > 22 {
+ f *= float64pow10[exp-22]
+ exp = 22
+ }
+ if f > 1e15 || f < -1e15 {
+ // the exponent was really too large.
+ return
+ }
+ return f * float64pow10[exp], true
+ case exp < 0 && exp >= -22: // int / 10^k
+ return f / float64pow10[-exp], true
+ }
+ return
+}
+
+// If possible to compute mantissa*10^exp to 32-bit float f exactly,
+// entirely in floating-point math, do so, avoiding the machinery above.
+func atof32exact(mantissa uint64, exp int, neg bool) (f float32, ok bool) {
+ if mantissa>>float32info.mantbits != 0 {
+ return
+ }
+ f = float32(mantissa)
+ if neg {
+ f = -f
+ }
+ switch {
+ case exp == 0:
+ return f, true
+ // Exact integers are <= 10^7.
+ // Exact powers of ten are <= 10^10.
+ case exp > 0 && exp <= 7+10: // int * 10^k
+ // If exponent is big but number of digits is not,
+ // can move a few zeros into the integer part.
+ if exp > 10 {
+ f *= float32pow10[exp-10]
+ exp = 10
+ }
+ if f > 1e7 || f < -1e7 {
+ // the exponent was really too large.
+ return
+ }
+ return f * float32pow10[exp], true
+ case exp < 0 && exp >= -10: // int / 10^k
+ return f / float32pow10[-exp], true
+ }
+ return
+}
+
+const fnParseFloat = "ParseFloat"
+
+func atof32(s []byte) (f float32, err error) {
+ if val, ok := special(s); ok {
+ return float32(val), nil
+ }
+
+ if optimize {
+ // Parse mantissa and exponent.
+ mantissa, exp, neg, trunc, ok := readFloat(s)
+ if ok {
+ // Try pure floating-point arithmetic conversion.
+ if !trunc {
+ if f, ok := atof32exact(mantissa, exp, neg); ok {
+ return f, nil
+ }
+ }
+ // Try another fast path.
+ ext := new(extFloat)
+ if ok := ext.AssignDecimal(mantissa, exp, neg, trunc, &float32info); ok {
+ b, ovf := ext.floatBits(&float32info)
+ f = math.Float32frombits(uint32(b))
+ if ovf {
+ err = rangeError(fnParseFloat, string(s))
+ }
+ return f, err
+ }
+ }
+ }
+ var d decimal
+ if !d.set(s) {
+ return 0, syntaxError(fnParseFloat, string(s))
+ }
+ b, ovf := d.floatBits(&float32info)
+ f = math.Float32frombits(uint32(b))
+ if ovf {
+ err = rangeError(fnParseFloat, string(s))
+ }
+ return f, err
+}
+
+func atof64(s []byte) (f float64, err error) {
+ if val, ok := special(s); ok {
+ return val, nil
+ }
+
+ if optimize {
+ // Parse mantissa and exponent.
+ mantissa, exp, neg, trunc, ok := readFloat(s)
+ if ok {
+ // Try pure floating-point arithmetic conversion.
+ if !trunc {
+ if f, ok := atof64exact(mantissa, exp, neg); ok {
+ return f, nil
+ }
+ }
+ // Try another fast path.
+ ext := new(extFloat)
+ if ok := ext.AssignDecimal(mantissa, exp, neg, trunc, &float64info); ok {
+ b, ovf := ext.floatBits(&float64info)
+ f = math.Float64frombits(b)
+ if ovf {
+ err = rangeError(fnParseFloat, string(s))
+ }
+ return f, err
+ }
+ }
+ }
+ var d decimal
+ if !d.set(s) {
+ return 0, syntaxError(fnParseFloat, string(s))
+ }
+ b, ovf := d.floatBits(&float64info)
+ f = math.Float64frombits(b)
+ if ovf {
+ err = rangeError(fnParseFloat, string(s))
+ }
+ return f, err
+}
+
+// ParseFloat converts the string s to a floating-point number
+// with the precision specified by bitSize: 32 for float32, or 64 for float64.
+// When bitSize=32, the result still has type float64, but it will be
+// convertible to float32 without changing its value.
+//
+// If s is well-formed and near a valid floating point number,
+// ParseFloat returns the nearest floating point number rounded
+// using IEEE754 unbiased rounding.
+//
+// The errors that ParseFloat returns have concrete type *NumError
+// and include err.Num = s.
+//
+// If s is not syntactically well-formed, ParseFloat returns err.Err = ErrSyntax.
+//
+// If s is syntactically well-formed but is more than 1/2 ULP
+// away from the largest floating point number of the given size,
+// ParseFloat returns f = ±Inf, err.Err = ErrRange.
+func ParseFloat(s []byte, bitSize int) (f float64, err error) {
+ if bitSize == 32 {
+ f1, err1 := atof32(s)
+ return float64(f1), err1
+ }
+ f1, err1 := atof64(s)
+ return f1, err1
+}
+
+// oroginal: strconv/decimal.go, but not exported, and needed for PareFloat.
+
+// Copyright 2009 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.
+
+// Multiprecision decimal numbers.
+// For floating-point formatting only; not general purpose.
+// Only operations are assign and (binary) left/right shift.
+// Can do binary floating point in multiprecision decimal precisely
+// because 2 divides 10; cannot do decimal floating point
+// in multiprecision binary precisely.
+
+type decimal struct {
+ d [800]byte // digits
+ nd int // number of digits used
+ dp int // decimal point
+ neg bool
+ trunc bool // discarded nonzero digits beyond d[:nd]
+}
+
+func (a *decimal) String() string {
+ n := 10 + a.nd
+ if a.dp > 0 {
+ n += a.dp
+ }
+ if a.dp < 0 {
+ n += -a.dp
+ }
+
+ buf := make([]byte, n)
+ w := 0
+ switch {
+ case a.nd == 0:
+ return "0"
+
+ case a.dp <= 0:
+ // zeros fill space between decimal point and digits
+ buf[w] = '0'
+ w++
+ buf[w] = '.'
+ w++
+ w += digitZero(buf[w : w+-a.dp])
+ w += copy(buf[w:], a.d[0:a.nd])
+
+ case a.dp < a.nd:
+ // decimal point in middle of digits
+ w += copy(buf[w:], a.d[0:a.dp])
+ buf[w] = '.'
+ w++
+ w += copy(buf[w:], a.d[a.dp:a.nd])
+
+ default:
+ // zeros fill space between digits and decimal point
+ w += copy(buf[w:], a.d[0:a.nd])
+ w += digitZero(buf[w : w+a.dp-a.nd])
+ }
+ return string(buf[0:w])
+}
+
+func digitZero(dst []byte) int {
+ for i := range dst {
+ dst[i] = '0'
+ }
+ return len(dst)
+}
+
+// trim trailing zeros from number.
+// (They are meaningless; the decimal point is tracked
+// independent of the number of digits.)
+func trim(a *decimal) {
+ for a.nd > 0 && a.d[a.nd-1] == '0' {
+ a.nd--
+ }
+ if a.nd == 0 {
+ a.dp = 0
+ }
+}
+
+// Assign v to a.
+func (a *decimal) Assign(v uint64) {
+ var buf [24]byte
+
+ // Write reversed decimal in buf.
+ n := 0
+ for v > 0 {
+ v1 := v / 10
+ v -= 10 * v1
+ buf[n] = byte(v + '0')
+ n++
+ v = v1
+ }
+
+ // Reverse again to produce forward decimal in a.d.
+ a.nd = 0
+ for n--; n >= 0; n-- {
+ a.d[a.nd] = buf[n]
+ a.nd++
+ }
+ a.dp = a.nd
+ trim(a)
+}
+
+// Maximum shift that we can do in one pass without overflow.
+// Signed int has 31 bits, and we have to be able to accommodate 9<<k.
+const maxShift = 27
+
+// Binary shift right (* 2) by k bits. k <= maxShift to avoid overflow.
+func rightShift(a *decimal, k uint) {
+ r := 0 // read pointer
+ w := 0 // write pointer
+
+ // Pick up enough leading digits to cover first shift.
+ n := 0
+ for ; n>>k == 0; r++ {
+ if r >= a.nd {
+ if n == 0 {
+ // a == 0; shouldn't get here, but handle anyway.
+ a.nd = 0
+ return
+ }
+ for n>>k == 0 {
+ n = n * 10
+ r++
+ }
+ break
+ }
+ c := int(a.d[r])
+ n = n*10 + c - '0'
+ }
+ a.dp -= r - 1
+
+ // Pick up a digit, put down a digit.
+ for ; r < a.nd; r++ {
+ c := int(a.d[r])
+ dig := n >> k
+ n -= dig << k
+ a.d[w] = byte(dig + '0')
+ w++
+ n = n*10 + c - '0'
+ }
+
+ // Put down extra digits.
+ for n > 0 {
+ dig := n >> k
+ n -= dig << k
+ if w < len(a.d) {
+ a.d[w] = byte(dig + '0')
+ w++
+ } else if dig > 0 {
+ a.trunc = true
+ }
+ n = n * 10
+ }
+
+ a.nd = w
+ trim(a)
+}
+
+// Cheat sheet for left shift: table indexed by shift count giving
+// number of new digits that will be introduced by that shift.
+//
+// For example, leftcheats[4] = {2, "625"}. That means that
+// if we are shifting by 4 (multiplying by 16), it will add 2 digits
+// when the string prefix is "625" through "999", and one fewer digit
+// if the string prefix is "000" through "624".
+//
+// Credit for this trick goes to Ken.
+
+type leftCheat struct {
+ delta int // number of new digits
+ cutoff string // minus one digit if original < a.
+}
+
+var leftcheats = []leftCheat{
+ // Leading digits of 1/2^i = 5^i.
+ // 5^23 is not an exact 64-bit floating point number,
+ // so have to use bc for the math.
+ /*
+ seq 27 | sed 's/^/5^/' | bc |
+ awk 'BEGIN{ print "\tleftCheat{ 0, \"\" }," }
+ {
+ log2 = log(2)/log(10)
+ printf("\tleftCheat{ %d, \"%s\" },\t// * %d\n",
+ int(log2*NR+1), $0, 2**NR)
+ }'
+ */
+ {0, ""},
+ {1, "5"}, // * 2
+ {1, "25"}, // * 4
+ {1, "125"}, // * 8
+ {2, "625"}, // * 16
+ {2, "3125"}, // * 32
+ {2, "15625"}, // * 64
+ {3, "78125"}, // * 128
+ {3, "390625"}, // * 256
+ {3, "1953125"}, // * 512
+ {4, "9765625"}, // * 1024
+ {4, "48828125"}, // * 2048
+ {4, "244140625"}, // * 4096
+ {4, "1220703125"}, // * 8192
+ {5, "6103515625"}, // * 16384
+ {5, "30517578125"}, // * 32768
+ {5, "152587890625"}, // * 65536
+ {6, "762939453125"}, // * 131072
+ {6, "3814697265625"}, // * 262144
+ {6, "19073486328125"}, // * 524288
+ {7, "95367431640625"}, // * 1048576
+ {7, "476837158203125"}, // * 2097152
+ {7, "2384185791015625"}, // * 4194304
+ {7, "11920928955078125"}, // * 8388608
+ {8, "59604644775390625"}, // * 16777216
+ {8, "298023223876953125"}, // * 33554432
+ {8, "1490116119384765625"}, // * 67108864
+ {9, "7450580596923828125"}, // * 134217728
+}
+
+// Is the leading prefix of b lexicographically less than s?
+func prefixIsLessThan(b []byte, s string) bool {
+ for i := 0; i < len(s); i++ {
+ if i >= len(b) {
+ return true
+ }
+ if b[i] != s[i] {
+ return b[i] < s[i]
+ }
+ }
+ return false
+}
+
+// Binary shift left (/ 2) by k bits. k <= maxShift to avoid overflow.
+func leftShift(a *decimal, k uint) {
+ delta := leftcheats[k].delta
+ if prefixIsLessThan(a.d[0:a.nd], leftcheats[k].cutoff) {
+ delta--
+ }
+
+ r := a.nd // read index
+ w := a.nd + delta // write index
+ n := 0
+
+ // Pick up a digit, put down a digit.
+ for r--; r >= 0; r-- {
+ n += (int(a.d[r]) - '0') << k
+ quo := n / 10
+ rem := n - 10*quo
+ w--
+ if w < len(a.d) {
+ a.d[w] = byte(rem + '0')
+ } else if rem != 0 {
+ a.trunc = true
+ }
+ n = quo
+ }
+
+ // Put down extra digits.
+ for n > 0 {
+ quo := n / 10
+ rem := n - 10*quo
+ w--
+ if w < len(a.d) {
+ a.d[w] = byte(rem + '0')
+ } else if rem != 0 {
+ a.trunc = true
+ }
+ n = quo
+ }
+
+ a.nd += delta
+ if a.nd >= len(a.d) {
+ a.nd = len(a.d)
+ }
+ a.dp += delta
+ trim(a)
+}
+
+// Binary shift left (k > 0) or right (k < 0).
+func (a *decimal) Shift(k int) {
+ switch {
+ case a.nd == 0:
+ // nothing to do: a == 0
+ case k > 0:
+ for k > maxShift {
+ leftShift(a, maxShift)
+ k -= maxShift
+ }
+ leftShift(a, uint(k))
+ case k < 0:
+ for k < -maxShift {
+ rightShift(a, maxShift)
+ k += maxShift
+ }
+ rightShift(a, uint(-k))
+ }
+}
+
+// If we chop a at nd digits, should we round up?
+func shouldRoundUp(a *decimal, nd int) bool {
+ if nd < 0 || nd >= a.nd {
+ return false
+ }
+ if a.d[nd] == '5' && nd+1 == a.nd { // exactly halfway - round to even
+ // if we truncated, a little higher than what's recorded - always round up
+ if a.trunc {
+ return true
+ }
+ return nd > 0 && (a.d[nd-1]-'0')%2 != 0
+ }
+ // not halfway - digit tells all
+ return a.d[nd] >= '5'
+}
+
+// Round a to nd digits (or fewer).
+// If nd is zero, it means we're rounding
+// just to the left of the digits, as in
+// 0.09 -> 0.1.
+func (a *decimal) Round(nd int) {
+ if nd < 0 || nd >= a.nd {
+ return
+ }
+ if shouldRoundUp(a, nd) {
+ a.RoundUp(nd)
+ } else {
+ a.RoundDown(nd)
+ }
+}
+
+// Round a down to nd digits (or fewer).
+func (a *decimal) RoundDown(nd int) {
+ if nd < 0 || nd >= a.nd {
+ return
+ }
+ a.nd = nd
+ trim(a)
+}
+
+// Round a up to nd digits (or fewer).
+func (a *decimal) RoundUp(nd int) {
+ if nd < 0 || nd >= a.nd {
+ return
+ }
+
+ // round up
+ for i := nd - 1; i >= 0; i-- {
+ c := a.d[i]
+ if c < '9' { // can stop after this digit
+ a.d[i]++
+ a.nd = i + 1
+ return
+ }
+ }
+
+ // Number is all 9s.
+ // Change to single 1 with adjusted decimal point.
+ a.d[0] = '1'
+ a.nd = 1
+ a.dp++
+}
+
+// Extract integer part, rounded appropriately.
+// No guarantees about overflow.
+func (a *decimal) RoundedInteger() uint64 {
+ if a.dp > 20 {
+ return 0xFFFFFFFFFFFFFFFF
+ }
+ var i int
+ n := uint64(0)
+ for i = 0; i < a.dp && i < a.nd; i++ {
+ n = n*10 + uint64(a.d[i]-'0')
+ }
+ for ; i < a.dp; i++ {
+ n *= 10
+ }
+ if shouldRoundUp(a, a.dp) {
+ n++
+ }
+ return n
+}
diff --git a/vendor/github.com/pquerna/ffjson/fflib/v1/internal/atoi.go b/vendor/github.com/pquerna/ffjson/fflib/v1/internal/atoi.go
new file mode 100644
index 000000000..06eb2ec29
--- /dev/null
+++ b/vendor/github.com/pquerna/ffjson/fflib/v1/internal/atoi.go
@@ -0,0 +1,213 @@
+/**
+ * Copyright 2014 Paul Querna
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+/* Portions of this file are on Go stdlib's strconv/atoi.go */
+// Copyright 2009 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 internal
+
+import (
+ "errors"
+ "strconv"
+)
+
+// ErrRange indicates that a value is out of range for the target type.
+var ErrRange = errors.New("value out of range")
+
+// ErrSyntax indicates that a value does not have the right syntax for the target type.
+var ErrSyntax = errors.New("invalid syntax")
+
+// A NumError records a failed conversion.
+type NumError struct {
+ Func string // the failing function (ParseBool, ParseInt, ParseUint, ParseFloat)
+ Num string // the input
+ Err error // the reason the conversion failed (ErrRange, ErrSyntax)
+}
+
+func (e *NumError) Error() string {
+ return "strconv." + e.Func + ": " + "parsing " + strconv.Quote(e.Num) + ": " + e.Err.Error()
+}
+
+func syntaxError(fn, str string) *NumError {
+ return &NumError{fn, str, ErrSyntax}
+}
+
+func rangeError(fn, str string) *NumError {
+ return &NumError{fn, str, ErrRange}
+}
+
+const intSize = 32 << uint(^uint(0)>>63)
+
+// IntSize is the size in bits of an int or uint value.
+const IntSize = intSize
+
+// Return the first number n such that n*base >= 1<<64.
+func cutoff64(base int) uint64 {
+ if base < 2 {
+ return 0
+ }
+ return (1<<64-1)/uint64(base) + 1
+}
+
+// ParseUint is like ParseInt but for unsigned numbers, and oeprating on []byte
+func ParseUint(s []byte, base int, bitSize int) (n uint64, err error) {
+ var cutoff, maxVal uint64
+
+ if bitSize == 0 {
+ bitSize = int(IntSize)
+ }
+
+ s0 := s
+ switch {
+ case len(s) < 1:
+ err = ErrSyntax
+ goto Error
+
+ case 2 <= base && base <= 36:
+ // valid base; nothing to do
+
+ case base == 0:
+ // Look for octal, hex prefix.
+ switch {
+ case s[0] == '0' && len(s) > 1 && (s[1] == 'x' || s[1] == 'X'):
+ base = 16
+ s = s[2:]
+ if len(s) < 1 {
+ err = ErrSyntax
+ goto Error
+ }
+ case s[0] == '0':
+ base = 8
+ default:
+ base = 10
+ }
+
+ default:
+ err = errors.New("invalid base " + strconv.Itoa(base))
+ goto Error
+ }
+
+ n = 0
+ cutoff = cutoff64(base)
+ maxVal = 1<<uint(bitSize) - 1
+
+ for i := 0; i < len(s); i++ {
+ var v byte
+ d := s[i]
+ switch {
+ case '0' <= d && d <= '9':
+ v = d - '0'
+ case 'a' <= d && d <= 'z':
+ v = d - 'a' + 10
+ case 'A' <= d && d <= 'Z':
+ v = d - 'A' + 10
+ default:
+ n = 0
+ err = ErrSyntax
+ goto Error
+ }
+ if int(v) >= base {
+ n = 0
+ err = ErrSyntax
+ goto Error
+ }
+
+ if n >= cutoff {
+ // n*base overflows
+ n = 1<<64 - 1
+ err = ErrRange
+ goto Error
+ }
+ n *= uint64(base)
+
+ n1 := n + uint64(v)
+ if n1 < n || n1 > maxVal {
+ // n+v overflows
+ n = 1<<64 - 1
+ err = ErrRange
+ goto Error
+ }
+ n = n1
+ }
+
+ return n, nil
+
+Error:
+ return n, &NumError{"ParseUint", string(s0), err}
+}
+
+// ParseInt interprets a string s in the given base (2 to 36) and
+// returns the corresponding value i. If base == 0, the base is
+// implied by the string's prefix: base 16 for "0x", base 8 for
+// "0", and base 10 otherwise.
+//
+// The bitSize argument specifies the integer type
+// that the result must fit into. Bit sizes 0, 8, 16, 32, and 64
+// correspond to int, int8, int16, int32, and int64.
+//
+// The errors that ParseInt returns have concrete type *NumError
+// and include err.Num = s. If s is empty or contains invalid
+// digits, err.Err = ErrSyntax and the returned value is 0;
+// if the value corresponding to s cannot be represented by a
+// signed integer of the given size, err.Err = ErrRange and the
+// returned value is the maximum magnitude integer of the
+// appropriate bitSize and sign.
+func ParseInt(s []byte, base int, bitSize int) (i int64, err error) {
+ const fnParseInt = "ParseInt"
+
+ if bitSize == 0 {
+ bitSize = int(IntSize)
+ }
+
+ // Empty string bad.
+ if len(s) == 0 {
+ return 0, syntaxError(fnParseInt, string(s))
+ }
+
+ // Pick off leading sign.
+ s0 := s
+ neg := false
+ if s[0] == '+' {
+ s = s[1:]
+ } else if s[0] == '-' {
+ neg = true
+ s = s[1:]
+ }
+
+ // Convert unsigned and check range.
+ var un uint64
+ un, err = ParseUint(s, base, bitSize)
+ if err != nil && err.(*NumError).Err != ErrRange {
+ err.(*NumError).Func = fnParseInt
+ err.(*NumError).Num = string(s0)
+ return 0, err
+ }
+ cutoff := uint64(1 << uint(bitSize-1))
+ if !neg && un >= cutoff {
+ return int64(cutoff - 1), rangeError(fnParseInt, string(s0))
+ }
+ if neg && un > cutoff {
+ return -int64(cutoff), rangeError(fnParseInt, string(s0))
+ }
+ n := int64(un)
+ if neg {
+ n = -n
+ }
+ return n, nil
+}
diff --git a/vendor/github.com/pquerna/ffjson/fflib/v1/internal/extfloat.go b/vendor/github.com/pquerna/ffjson/fflib/v1/internal/extfloat.go
new file mode 100644
index 000000000..ab791085a
--- /dev/null
+++ b/vendor/github.com/pquerna/ffjson/fflib/v1/internal/extfloat.go
@@ -0,0 +1,668 @@
+// Copyright 2011 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 internal
+
+// An extFloat represents an extended floating-point number, with more
+// precision than a float64. It does not try to save bits: the
+// number represented by the structure is mant*(2^exp), with a negative
+// sign if neg is true.
+type extFloat struct {
+ mant uint64
+ exp int
+ neg bool
+}
+
+// Powers of ten taken from double-conversion library.
+// http://code.google.com/p/double-conversion/
+const (
+ firstPowerOfTen = -348
+ stepPowerOfTen = 8
+)
+
+var smallPowersOfTen = [...]extFloat{
+ {1 << 63, -63, false}, // 1
+ {0xa << 60, -60, false}, // 1e1
+ {0x64 << 57, -57, false}, // 1e2
+ {0x3e8 << 54, -54, false}, // 1e3
+ {0x2710 << 50, -50, false}, // 1e4
+ {0x186a0 << 47, -47, false}, // 1e5
+ {0xf4240 << 44, -44, false}, // 1e6
+ {0x989680 << 40, -40, false}, // 1e7
+}
+
+var powersOfTen = [...]extFloat{
+ {0xfa8fd5a0081c0288, -1220, false}, // 10^-348
+ {0xbaaee17fa23ebf76, -1193, false}, // 10^-340
+ {0x8b16fb203055ac76, -1166, false}, // 10^-332
+ {0xcf42894a5dce35ea, -1140, false}, // 10^-324
+ {0x9a6bb0aa55653b2d, -1113, false}, // 10^-316
+ {0xe61acf033d1a45df, -1087, false}, // 10^-308
+ {0xab70fe17c79ac6ca, -1060, false}, // 10^-300
+ {0xff77b1fcbebcdc4f, -1034, false}, // 10^-292
+ {0xbe5691ef416bd60c, -1007, false}, // 10^-284
+ {0x8dd01fad907ffc3c, -980, false}, // 10^-276
+ {0xd3515c2831559a83, -954, false}, // 10^-268
+ {0x9d71ac8fada6c9b5, -927, false}, // 10^-260
+ {0xea9c227723ee8bcb, -901, false}, // 10^-252
+ {0xaecc49914078536d, -874, false}, // 10^-244
+ {0x823c12795db6ce57, -847, false}, // 10^-236
+ {0xc21094364dfb5637, -821, false}, // 10^-228
+ {0x9096ea6f3848984f, -794, false}, // 10^-220
+ {0xd77485cb25823ac7, -768, false}, // 10^-212
+ {0xa086cfcd97bf97f4, -741, false}, // 10^-204
+ {0xef340a98172aace5, -715, false}, // 10^-196
+ {0xb23867fb2a35b28e, -688, false}, // 10^-188
+ {0x84c8d4dfd2c63f3b, -661, false}, // 10^-180
+ {0xc5dd44271ad3cdba, -635, false}, // 10^-172
+ {0x936b9fcebb25c996, -608, false}, // 10^-164
+ {0xdbac6c247d62a584, -582, false}, // 10^-156
+ {0xa3ab66580d5fdaf6, -555, false}, // 10^-148
+ {0xf3e2f893dec3f126, -529, false}, // 10^-140
+ {0xb5b5ada8aaff80b8, -502, false}, // 10^-132
+ {0x87625f056c7c4a8b, -475, false}, // 10^-124
+ {0xc9bcff6034c13053, -449, false}, // 10^-116
+ {0x964e858c91ba2655, -422, false}, // 10^-108
+ {0xdff9772470297ebd, -396, false}, // 10^-100
+ {0xa6dfbd9fb8e5b88f, -369, false}, // 10^-92
+ {0xf8a95fcf88747d94, -343, false}, // 10^-84
+ {0xb94470938fa89bcf, -316, false}, // 10^-76
+ {0x8a08f0f8bf0f156b, -289, false}, // 10^-68
+ {0xcdb02555653131b6, -263, false}, // 10^-60
+ {0x993fe2c6d07b7fac, -236, false}, // 10^-52
+ {0xe45c10c42a2b3b06, -210, false}, // 10^-44
+ {0xaa242499697392d3, -183, false}, // 10^-36
+ {0xfd87b5f28300ca0e, -157, false}, // 10^-28
+ {0xbce5086492111aeb, -130, false}, // 10^-20
+ {0x8cbccc096f5088cc, -103, false}, // 10^-12
+ {0xd1b71758e219652c, -77, false}, // 10^-4
+ {0x9c40000000000000, -50, false}, // 10^4
+ {0xe8d4a51000000000, -24, false}, // 10^12
+ {0xad78ebc5ac620000, 3, false}, // 10^20
+ {0x813f3978f8940984, 30, false}, // 10^28
+ {0xc097ce7bc90715b3, 56, false}, // 10^36
+ {0x8f7e32ce7bea5c70, 83, false}, // 10^44
+ {0xd5d238a4abe98068, 109, false}, // 10^52
+ {0x9f4f2726179a2245, 136, false}, // 10^60
+ {0xed63a231d4c4fb27, 162, false}, // 10^68
+ {0xb0de65388cc8ada8, 189, false}, // 10^76
+ {0x83c7088e1aab65db, 216, false}, // 10^84
+ {0xc45d1df942711d9a, 242, false}, // 10^92
+ {0x924d692ca61be758, 269, false}, // 10^100
+ {0xda01ee641a708dea, 295, false}, // 10^108
+ {0xa26da3999aef774a, 322, false}, // 10^116
+ {0xf209787bb47d6b85, 348, false}, // 10^124
+ {0xb454e4a179dd1877, 375, false}, // 10^132
+ {0x865b86925b9bc5c2, 402, false}, // 10^140
+ {0xc83553c5c8965d3d, 428, false}, // 10^148
+ {0x952ab45cfa97a0b3, 455, false}, // 10^156
+ {0xde469fbd99a05fe3, 481, false}, // 10^164
+ {0xa59bc234db398c25, 508, false}, // 10^172
+ {0xf6c69a72a3989f5c, 534, false}, // 10^180
+ {0xb7dcbf5354e9bece, 561, false}, // 10^188
+ {0x88fcf317f22241e2, 588, false}, // 10^196
+ {0xcc20ce9bd35c78a5, 614, false}, // 10^204
+ {0x98165af37b2153df, 641, false}, // 10^212
+ {0xe2a0b5dc971f303a, 667, false}, // 10^220
+ {0xa8d9d1535ce3b396, 694, false}, // 10^228
+ {0xfb9b7cd9a4a7443c, 720, false}, // 10^236
+ {0xbb764c4ca7a44410, 747, false}, // 10^244
+ {0x8bab8eefb6409c1a, 774, false}, // 10^252
+ {0xd01fef10a657842c, 800, false}, // 10^260
+ {0x9b10a4e5e9913129, 827, false}, // 10^268
+ {0xe7109bfba19c0c9d, 853, false}, // 10^276
+ {0xac2820d9623bf429, 880, false}, // 10^284
+ {0x80444b5e7aa7cf85, 907, false}, // 10^292
+ {0xbf21e44003acdd2d, 933, false}, // 10^300
+ {0x8e679c2f5e44ff8f, 960, false}, // 10^308
+ {0xd433179d9c8cb841, 986, false}, // 10^316
+ {0x9e19db92b4e31ba9, 1013, false}, // 10^324
+ {0xeb96bf6ebadf77d9, 1039, false}, // 10^332
+ {0xaf87023b9bf0ee6b, 1066, false}, // 10^340
+}
+
+// floatBits returns the bits of the float64 that best approximates
+// the extFloat passed as receiver. Overflow is set to true if
+// the resulting float64 is ±Inf.
+func (f *extFloat) floatBits(flt *floatInfo) (bits uint64, overflow bool) {
+ f.Normalize()
+
+ exp := f.exp + 63
+
+ // Exponent too small.
+ if exp < flt.bias+1 {
+ n := flt.bias + 1 - exp
+ f.mant >>= uint(n)
+ exp += n
+ }
+
+ // Extract 1+flt.mantbits bits from the 64-bit mantissa.
+ mant := f.mant >> (63 - flt.mantbits)
+ if f.mant&(1<<(62-flt.mantbits)) != 0 {
+ // Round up.
+ mant += 1
+ }
+
+ // Rounding might have added a bit; shift down.
+ if mant == 2<<flt.mantbits {
+ mant >>= 1
+ exp++
+ }
+
+ // Infinities.
+ if exp-flt.bias >= 1<<flt.expbits-1 {
+ // ±Inf
+ mant = 0
+ exp = 1<<flt.expbits - 1 + flt.bias
+ overflow = true
+ } else if mant&(1<<flt.mantbits) == 0 {
+ // Denormalized?
+ exp = flt.bias
+ }
+ // Assemble bits.
+ bits = mant & (uint64(1)<<flt.mantbits - 1)
+ bits |= uint64((exp-flt.bias)&(1<<flt.expbits-1)) << flt.mantbits
+ if f.neg {
+ bits |= 1 << (flt.mantbits + flt.expbits)
+ }
+ return
+}
+
+// AssignComputeBounds sets f to the floating point value
+// defined by mant, exp and precision given by flt. It returns
+// lower, upper such that any number in the closed interval
+// [lower, upper] is converted back to the same floating point number.
+func (f *extFloat) AssignComputeBounds(mant uint64, exp int, neg bool, flt *floatInfo) (lower, upper extFloat) {
+ f.mant = mant
+ f.exp = exp - int(flt.mantbits)
+ f.neg = neg
+ if f.exp <= 0 && mant == (mant>>uint(-f.exp))<<uint(-f.exp) {
+ // An exact integer
+ f.mant >>= uint(-f.exp)
+ f.exp = 0
+ return *f, *f
+ }
+ expBiased := exp - flt.bias
+
+ upper = extFloat{mant: 2*f.mant + 1, exp: f.exp - 1, neg: f.neg}
+ if mant != 1<<flt.mantbits || expBiased == 1 {
+ lower = extFloat{mant: 2*f.mant - 1, exp: f.exp - 1, neg: f.neg}
+ } else {
+ lower = extFloat{mant: 4*f.mant - 1, exp: f.exp - 2, neg: f.neg}
+ }
+ return
+}
+
+// Normalize normalizes f so that the highest bit of the mantissa is
+// set, and returns the number by which the mantissa was left-shifted.
+func (f *extFloat) Normalize() (shift uint) {
+ mant, exp := f.mant, f.exp
+ if mant == 0 {
+ return 0
+ }
+ if mant>>(64-32) == 0 {
+ mant <<= 32
+ exp -= 32
+ }
+ if mant>>(64-16) == 0 {
+ mant <<= 16
+ exp -= 16
+ }
+ if mant>>(64-8) == 0 {
+ mant <<= 8
+ exp -= 8
+ }
+ if mant>>(64-4) == 0 {
+ mant <<= 4
+ exp -= 4
+ }
+ if mant>>(64-2) == 0 {
+ mant <<= 2
+ exp -= 2
+ }
+ if mant>>(64-1) == 0 {
+ mant <<= 1
+ exp -= 1
+ }
+ shift = uint(f.exp - exp)
+ f.mant, f.exp = mant, exp
+ return
+}
+
+// Multiply sets f to the product f*g: the result is correctly rounded,
+// but not normalized.
+func (f *extFloat) Multiply(g extFloat) {
+ fhi, flo := f.mant>>32, uint64(uint32(f.mant))
+ ghi, glo := g.mant>>32, uint64(uint32(g.mant))
+
+ // Cross products.
+ cross1 := fhi * glo
+ cross2 := flo * ghi
+
+ // f.mant*g.mant is fhi*ghi << 64 + (cross1+cross2) << 32 + flo*glo
+ f.mant = fhi*ghi + (cross1 >> 32) + (cross2 >> 32)
+ rem := uint64(uint32(cross1)) + uint64(uint32(cross2)) + ((flo * glo) >> 32)
+ // Round up.
+ rem += (1 << 31)
+
+ f.mant += (rem >> 32)
+ f.exp = f.exp + g.exp + 64
+}
+
+var uint64pow10 = [...]uint64{
+ 1, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
+ 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
+}
+
+// AssignDecimal sets f to an approximate value mantissa*10^exp. It
+// returns true if the value represented by f is guaranteed to be the
+// best approximation of d after being rounded to a float64 or
+// float32 depending on flt.
+func (f *extFloat) AssignDecimal(mantissa uint64, exp10 int, neg bool, trunc bool, flt *floatInfo) (ok bool) {
+ const uint64digits = 19
+ const errorscale = 8
+ errors := 0 // An upper bound for error, computed in errorscale*ulp.
+ if trunc {
+ // the decimal number was truncated.
+ errors += errorscale / 2
+ }
+
+ f.mant = mantissa
+ f.exp = 0
+ f.neg = neg
+
+ // Multiply by powers of ten.
+ i := (exp10 - firstPowerOfTen) / stepPowerOfTen
+ if exp10 < firstPowerOfTen || i >= len(powersOfTen) {
+ return false
+ }
+ adjExp := (exp10 - firstPowerOfTen) % stepPowerOfTen
+
+ // We multiply by exp%step
+ if adjExp < uint64digits && mantissa < uint64pow10[uint64digits-adjExp] {
+ // We can multiply the mantissa exactly.
+ f.mant *= uint64pow10[adjExp]
+ f.Normalize()
+ } else {
+ f.Normalize()
+ f.Multiply(smallPowersOfTen[adjExp])
+ errors += errorscale / 2
+ }
+
+ // We multiply by 10 to the exp - exp%step.
+ f.Multiply(powersOfTen[i])
+ if errors > 0 {
+ errors += 1
+ }
+ errors += errorscale / 2
+
+ // Normalize
+ shift := f.Normalize()
+ errors <<= shift
+
+ // Now f is a good approximation of the decimal.
+ // Check whether the error is too large: that is, if the mantissa
+ // is perturbated by the error, the resulting float64 will change.
+ // The 64 bits mantissa is 1 + 52 bits for float64 + 11 extra bits.
+ //
+ // In many cases the approximation will be good enough.
+ denormalExp := flt.bias - 63
+ var extrabits uint
+ if f.exp <= denormalExp {
+ // f.mant * 2^f.exp is smaller than 2^(flt.bias+1).
+ extrabits = uint(63 - flt.mantbits + 1 + uint(denormalExp-f.exp))
+ } else {
+ extrabits = uint(63 - flt.mantbits)
+ }
+
+ halfway := uint64(1) << (extrabits - 1)
+ mant_extra := f.mant & (1<<extrabits - 1)
+
+ // Do a signed comparison here! If the error estimate could make
+ // the mantissa round differently for the conversion to double,
+ // then we can't give a definite answer.
+ if int64(halfway)-int64(errors) < int64(mant_extra) &&
+ int64(mant_extra) < int64(halfway)+int64(errors) {
+ return false
+ }
+ return true
+}
+
+// Frexp10 is an analogue of math.Frexp for decimal powers. It scales
+// f by an approximate power of ten 10^-exp, and returns exp10, so
+// that f*10^exp10 has the same value as the old f, up to an ulp,
+// as well as the index of 10^-exp in the powersOfTen table.
+func (f *extFloat) frexp10() (exp10, index int) {
+ // The constants expMin and expMax constrain the final value of the
+ // binary exponent of f. We want a small integral part in the result
+ // because finding digits of an integer requires divisions, whereas
+ // digits of the fractional part can be found by repeatedly multiplying
+ // by 10.
+ const expMin = -60
+ const expMax = -32
+ // Find power of ten such that x * 10^n has a binary exponent
+ // between expMin and expMax.
+ approxExp10 := ((expMin+expMax)/2 - f.exp) * 28 / 93 // log(10)/log(2) is close to 93/28.
+ i := (approxExp10 - firstPowerOfTen) / stepPowerOfTen
+Loop:
+ for {
+ exp := f.exp + powersOfTen[i].exp + 64
+ switch {
+ case exp < expMin:
+ i++
+ case exp > expMax:
+ i--
+ default:
+ break Loop
+ }
+ }
+ // Apply the desired decimal shift on f. It will have exponent
+ // in the desired range. This is multiplication by 10^-exp10.
+ f.Multiply(powersOfTen[i])
+
+ return -(firstPowerOfTen + i*stepPowerOfTen), i
+}
+
+// frexp10Many applies a common shift by a power of ten to a, b, c.
+func frexp10Many(a, b, c *extFloat) (exp10 int) {
+ exp10, i := c.frexp10()
+ a.Multiply(powersOfTen[i])
+ b.Multiply(powersOfTen[i])
+ return
+}
+
+// FixedDecimal stores in d the first n significant digits
+// of the decimal representation of f. It returns false
+// if it cannot be sure of the answer.
+func (f *extFloat) FixedDecimal(d *decimalSlice, n int) bool {
+ if f.mant == 0 {
+ d.nd = 0
+ d.dp = 0
+ d.neg = f.neg
+ return true
+ }
+ if n == 0 {
+ panic("strconv: internal error: extFloat.FixedDecimal called with n == 0")
+ }
+ // Multiply by an appropriate power of ten to have a reasonable
+ // number to process.
+ f.Normalize()
+ exp10, _ := f.frexp10()
+
+ shift := uint(-f.exp)
+ integer := uint32(f.mant >> shift)
+ fraction := f.mant - (uint64(integer) << shift)
+ ε := uint64(1) // ε is the uncertainty we have on the mantissa of f.
+
+ // Write exactly n digits to d.
+ needed := n // how many digits are left to write.
+ integerDigits := 0 // the number of decimal digits of integer.
+ pow10 := uint64(1) // the power of ten by which f was scaled.
+ for i, pow := 0, uint64(1); i < 20; i++ {
+ if pow > uint64(integer) {
+ integerDigits = i
+ break
+ }
+ pow *= 10
+ }
+ rest := integer
+ if integerDigits > needed {
+ // the integral part is already large, trim the last digits.
+ pow10 = uint64pow10[integerDigits-needed]
+ integer /= uint32(pow10)
+ rest -= integer * uint32(pow10)
+ } else {
+ rest = 0
+ }
+
+ // Write the digits of integer: the digits of rest are omitted.
+ var buf [32]byte
+ pos := len(buf)
+ for v := integer; v > 0; {
+ v1 := v / 10
+ v -= 10 * v1
+ pos--
+ buf[pos] = byte(v + '0')
+ v = v1
+ }
+ for i := pos; i < len(buf); i++ {
+ d.d[i-pos] = buf[i]
+ }
+ nd := len(buf) - pos
+ d.nd = nd
+ d.dp = integerDigits + exp10
+ needed -= nd
+
+ if needed > 0 {
+ if rest != 0 || pow10 != 1 {
+ panic("strconv: internal error, rest != 0 but needed > 0")
+ }
+ // Emit digits for the fractional part. Each time, 10*fraction
+ // fits in a uint64 without overflow.
+ for needed > 0 {
+ fraction *= 10
+ ε *= 10 // the uncertainty scales as we multiply by ten.
+ if 2*ε > 1<<shift {
+ // the error is so large it could modify which digit to write, abort.
+ return false
+ }
+ digit := fraction >> shift
+ d.d[nd] = byte(digit + '0')
+ fraction -= digit << shift
+ nd++
+ needed--
+ }
+ d.nd = nd
+ }
+
+ // We have written a truncation of f (a numerator / 10^d.dp). The remaining part
+ // can be interpreted as a small number (< 1) to be added to the last digit of the
+ // numerator.
+ //
+ // If rest > 0, the amount is:
+ // (rest<<shift | fraction) / (pow10 << shift)
+ // fraction being known with a ±ε uncertainty.
+ // The fact that n > 0 guarantees that pow10 << shift does not overflow a uint64.
+ //
+ // If rest = 0, pow10 == 1 and the amount is
+ // fraction / (1 << shift)
+ // fraction being known with a ±ε uncertainty.
+ //
+ // We pass this information to the rounding routine for adjustment.
+
+ ok := adjustLastDigitFixed(d, uint64(rest)<<shift|fraction, pow10, shift, ε)
+ if !ok {
+ return false
+ }
+ // Trim trailing zeros.
+ for i := d.nd - 1; i >= 0; i-- {
+ if d.d[i] != '0' {
+ d.nd = i + 1
+ break
+ }
+ }
+ return true
+}
+
+// adjustLastDigitFixed assumes d contains the representation of the integral part
+// of some number, whose fractional part is num / (den << shift). The numerator
+// num is only known up to an uncertainty of size ε, assumed to be less than
+// (den << shift)/2.
+//
+// It will increase the last digit by one to account for correct rounding, typically
+// when the fractional part is greater than 1/2, and will return false if ε is such
+// that no correct answer can be given.
+func adjustLastDigitFixed(d *decimalSlice, num, den uint64, shift uint, ε uint64) bool {
+ if num > den<<shift {
+ panic("strconv: num > den<<shift in adjustLastDigitFixed")
+ }
+ if 2*ε > den<<shift {
+ panic("strconv: ε > (den<<shift)/2")
+ }
+ if 2*(num+ε) < den<<shift {
+ return true
+ }
+ if 2*(num-ε) > den<<shift {
+ // increment d by 1.
+ i := d.nd - 1
+ for ; i >= 0; i-- {
+ if d.d[i] == '9' {
+ d.nd--
+ } else {
+ break
+ }
+ }
+ if i < 0 {
+ d.d[0] = '1'
+ d.nd = 1
+ d.dp++
+ } else {
+ d.d[i]++
+ }
+ return true
+ }
+ return false
+}
+
+// ShortestDecimal stores in d the shortest decimal representation of f
+// which belongs to the open interval (lower, upper), where f is supposed
+// to lie. It returns false whenever the result is unsure. The implementation
+// uses the Grisu3 algorithm.
+func (f *extFloat) ShortestDecimal(d *decimalSlice, lower, upper *extFloat) bool {
+ if f.mant == 0 {
+ d.nd = 0
+ d.dp = 0
+ d.neg = f.neg
+ return true
+ }
+ if f.exp == 0 && *lower == *f && *lower == *upper {
+ // an exact integer.
+ var buf [24]byte
+ n := len(buf) - 1
+ for v := f.mant; v > 0; {
+ v1 := v / 10
+ v -= 10 * v1
+ buf[n] = byte(v + '0')
+ n--
+ v = v1
+ }
+ nd := len(buf) - n - 1
+ for i := 0; i < nd; i++ {
+ d.d[i] = buf[n+1+i]
+ }
+ d.nd, d.dp = nd, nd
+ for d.nd > 0 && d.d[d.nd-1] == '0' {
+ d.nd--
+ }
+ if d.nd == 0 {
+ d.dp = 0
+ }
+ d.neg = f.neg
+ return true
+ }
+ upper.Normalize()
+ // Uniformize exponents.
+ if f.exp > upper.exp {
+ f.mant <<= uint(f.exp - upper.exp)
+ f.exp = upper.exp
+ }
+ if lower.exp > upper.exp {
+ lower.mant <<= uint(lower.exp - upper.exp)
+ lower.exp = upper.exp
+ }
+
+ exp10 := frexp10Many(lower, f, upper)
+ // Take a safety margin due to rounding in frexp10Many, but we lose precision.
+ upper.mant++
+ lower.mant--
+
+ // The shortest representation of f is either rounded up or down, but
+ // in any case, it is a truncation of upper.
+ shift := uint(-upper.exp)
+ integer := uint32(upper.mant >> shift)
+ fraction := upper.mant - (uint64(integer) << shift)
+
+ // How far we can go down from upper until the result is wrong.
+ allowance := upper.mant - lower.mant
+ // How far we should go to get a very precise result.
+ targetDiff := upper.mant - f.mant
+
+ // Count integral digits: there are at most 10.
+ var integerDigits int
+ for i, pow := 0, uint64(1); i < 20; i++ {
+ if pow > uint64(integer) {
+ integerDigits = i
+ break
+ }
+ pow *= 10
+ }
+ for i := 0; i < integerDigits; i++ {
+ pow := uint64pow10[integerDigits-i-1]
+ digit := integer / uint32(pow)
+ d.d[i] = byte(digit + '0')
+ integer -= digit * uint32(pow)
+ // evaluate whether we should stop.
+ if currentDiff := uint64(integer)<<shift + fraction; currentDiff < allowance {
+ d.nd = i + 1
+ d.dp = integerDigits + exp10
+ d.neg = f.neg
+ // Sometimes allowance is so large the last digit might need to be
+ // decremented to get closer to f.
+ return adjustLastDigit(d, currentDiff, targetDiff, allowance, pow<<shift, 2)
+ }
+ }
+ d.nd = integerDigits
+ d.dp = d.nd + exp10
+ d.neg = f.neg
+
+ // Compute digits of the fractional part. At each step fraction does not
+ // overflow. The choice of minExp implies that fraction is less than 2^60.
+ var digit int
+ multiplier := uint64(1)
+ for {
+ fraction *= 10
+ multiplier *= 10
+ digit = int(fraction >> shift)
+ d.d[d.nd] = byte(digit + '0')
+ d.nd++
+ fraction -= uint64(digit) << shift
+ if fraction < allowance*multiplier {
+ // We are in the admissible range. Note that if allowance is about to
+ // overflow, that is, allowance > 2^64/10, the condition is automatically
+ // true due to the limited range of fraction.
+ return adjustLastDigit(d,
+ fraction, targetDiff*multiplier, allowance*multiplier,
+ 1<<shift, multiplier*2)
+ }
+ }
+}
+
+// adjustLastDigit modifies d = x-currentDiff*ε, to get closest to
+// d = x-targetDiff*ε, without becoming smaller than x-maxDiff*ε.
+// It assumes that a decimal digit is worth ulpDecimal*ε, and that
+// all data is known with a error estimate of ulpBinary*ε.
+func adjustLastDigit(d *decimalSlice, currentDiff, targetDiff, maxDiff, ulpDecimal, ulpBinary uint64) bool {
+ if ulpDecimal < 2*ulpBinary {
+ // Approximation is too wide.
+ return false
+ }
+ for currentDiff+ulpDecimal/2+ulpBinary < targetDiff {
+ d.d[d.nd-1]--
+ currentDiff += ulpDecimal
+ }
+ if currentDiff+ulpDecimal <= targetDiff+ulpDecimal/2+ulpBinary {
+ // we have two choices, and don't know what to do.
+ return false
+ }
+ if currentDiff < ulpBinary || currentDiff > maxDiff-ulpBinary {
+ // we went too far
+ return false
+ }
+ if d.nd == 1 && d.d[0] == '0' {
+ // the number has actually reached zero.
+ d.nd = 0
+ d.dp = 0
+ }
+ return true
+}
diff --git a/vendor/github.com/pquerna/ffjson/fflib/v1/internal/ftoa.go b/vendor/github.com/pquerna/ffjson/fflib/v1/internal/ftoa.go
new file mode 100644
index 000000000..253f83b45
--- /dev/null
+++ b/vendor/github.com/pquerna/ffjson/fflib/v1/internal/ftoa.go
@@ -0,0 +1,475 @@
+// Copyright 2009 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.
+
+// Binary to decimal floating point conversion.
+// Algorithm:
+// 1) store mantissa in multiprecision decimal
+// 2) shift decimal by exponent
+// 3) read digits out & format
+
+package internal
+
+import "math"
+
+// TODO: move elsewhere?
+type floatInfo struct {
+ mantbits uint
+ expbits uint
+ bias int
+}
+
+var float32info = floatInfo{23, 8, -127}
+var float64info = floatInfo{52, 11, -1023}
+
+// FormatFloat converts the floating-point number f to a string,
+// according to the format fmt and precision prec. It rounds the
+// result assuming that the original was obtained from a floating-point
+// value of bitSize bits (32 for float32, 64 for float64).
+//
+// The format fmt is one of
+// 'b' (-ddddp±ddd, a binary exponent),
+// 'e' (-d.dddde±dd, a decimal exponent),
+// 'E' (-d.ddddE±dd, a decimal exponent),
+// 'f' (-ddd.dddd, no exponent),
+// 'g' ('e' for large exponents, 'f' otherwise), or
+// 'G' ('E' for large exponents, 'f' otherwise).
+//
+// The precision prec controls the number of digits
+// (excluding the exponent) printed by the 'e', 'E', 'f', 'g', and 'G' formats.
+// For 'e', 'E', and 'f' it is the number of digits after the decimal point.
+// For 'g' and 'G' it is the total number of digits.
+// The special precision -1 uses the smallest number of digits
+// necessary such that ParseFloat will return f exactly.
+func formatFloat(f float64, fmt byte, prec, bitSize int) string {
+ return string(genericFtoa(make([]byte, 0, max(prec+4, 24)), f, fmt, prec, bitSize))
+}
+
+// AppendFloat appends the string form of the floating-point number f,
+// as generated by FormatFloat, to dst and returns the extended buffer.
+func appendFloat(dst []byte, f float64, fmt byte, prec int, bitSize int) []byte {
+ return genericFtoa(dst, f, fmt, prec, bitSize)
+}
+
+func genericFtoa(dst []byte, val float64, fmt byte, prec, bitSize int) []byte {
+ var bits uint64
+ var flt *floatInfo
+ switch bitSize {
+ case 32:
+ bits = uint64(math.Float32bits(float32(val)))
+ flt = &float32info
+ case 64:
+ bits = math.Float64bits(val)
+ flt = &float64info
+ default:
+ panic("strconv: illegal AppendFloat/FormatFloat bitSize")
+ }
+
+ neg := bits>>(flt.expbits+flt.mantbits) != 0
+ exp := int(bits>>flt.mantbits) & (1<<flt.expbits - 1)
+ mant := bits & (uint64(1)<<flt.mantbits - 1)
+
+ switch exp {
+ case 1<<flt.expbits - 1:
+ // Inf, NaN
+ var s string
+ switch {
+ case mant != 0:
+ s = "NaN"
+ case neg:
+ s = "-Inf"
+ default:
+ s = "+Inf"
+ }
+ return append(dst, s...)
+
+ case 0:
+ // denormalized
+ exp++
+
+ default:
+ // add implicit top bit
+ mant |= uint64(1) << flt.mantbits
+ }
+ exp += flt.bias
+
+ // Pick off easy binary format.
+ if fmt == 'b' {
+ return fmtB(dst, neg, mant, exp, flt)
+ }
+
+ if !optimize {
+ return bigFtoa(dst, prec, fmt, neg, mant, exp, flt)
+ }
+
+ var digs decimalSlice
+ ok := false
+ // Negative precision means "only as much as needed to be exact."
+ shortest := prec < 0
+ if shortest {
+ // Try Grisu3 algorithm.
+ f := new(extFloat)
+ lower, upper := f.AssignComputeBounds(mant, exp, neg, flt)
+ var buf [32]byte
+ digs.d = buf[:]
+ ok = f.ShortestDecimal(&digs, &lower, &upper)
+ if !ok {
+ return bigFtoa(dst, prec, fmt, neg, mant, exp, flt)
+ }
+ // Precision for shortest representation mode.
+ switch fmt {
+ case 'e', 'E':
+ prec = digs.nd - 1
+ case 'f':
+ prec = max(digs.nd-digs.dp, 0)
+ case 'g', 'G':
+ prec = digs.nd
+ }
+ } else if fmt != 'f' {
+ // Fixed number of digits.
+ digits := prec
+ switch fmt {
+ case 'e', 'E':
+ digits++
+ case 'g', 'G':
+ if prec == 0 {
+ prec = 1
+ }
+ digits = prec
+ }
+ if digits <= 15 {
+ // try fast algorithm when the number of digits is reasonable.
+ var buf [24]byte
+ digs.d = buf[:]
+ f := extFloat{mant, exp - int(flt.mantbits), neg}
+ ok = f.FixedDecimal(&digs, digits)
+ }
+ }
+ if !ok {
+ return bigFtoa(dst, prec, fmt, neg, mant, exp, flt)
+ }
+ return formatDigits(dst, shortest, neg, digs, prec, fmt)
+}
+
+// bigFtoa uses multiprecision computations to format a float.
+func bigFtoa(dst []byte, prec int, fmt byte, neg bool, mant uint64, exp int, flt *floatInfo) []byte {
+ d := new(decimal)
+ d.Assign(mant)
+ d.Shift(exp - int(flt.mantbits))
+ var digs decimalSlice
+ shortest := prec < 0
+ if shortest {
+ roundShortest(d, mant, exp, flt)
+ digs = decimalSlice{d: d.d[:], nd: d.nd, dp: d.dp}
+ // Precision for shortest representation mode.
+ switch fmt {
+ case 'e', 'E':
+ prec = digs.nd - 1
+ case 'f':
+ prec = max(digs.nd-digs.dp, 0)
+ case 'g', 'G':
+ prec = digs.nd
+ }
+ } else {
+ // Round appropriately.
+ switch fmt {
+ case 'e', 'E':
+ d.Round(prec + 1)
+ case 'f':
+ d.Round(d.dp + prec)
+ case 'g', 'G':
+ if prec == 0 {
+ prec = 1
+ }
+ d.Round(prec)
+ }
+ digs = decimalSlice{d: d.d[:], nd: d.nd, dp: d.dp}
+ }
+ return formatDigits(dst, shortest, neg, digs, prec, fmt)
+}
+
+func formatDigits(dst []byte, shortest bool, neg bool, digs decimalSlice, prec int, fmt byte) []byte {
+ switch fmt {
+ case 'e', 'E':
+ return fmtE(dst, neg, digs, prec, fmt)
+ case 'f':
+ return fmtF(dst, neg, digs, prec)
+ case 'g', 'G':
+ // trailing fractional zeros in 'e' form will be trimmed.
+ eprec := prec
+ if eprec > digs.nd && digs.nd >= digs.dp {
+ eprec = digs.nd
+ }
+ // %e is used if the exponent from the conversion
+ // is less than -4 or greater than or equal to the precision.
+ // if precision was the shortest possible, use precision 6 for this decision.
+ if shortest {
+ eprec = 6
+ }
+ exp := digs.dp - 1
+ if exp < -4 || exp >= eprec {
+ if prec > digs.nd {
+ prec = digs.nd
+ }
+ return fmtE(dst, neg, digs, prec-1, fmt+'e'-'g')
+ }
+ if prec > digs.dp {
+ prec = digs.nd
+ }
+ return fmtF(dst, neg, digs, max(prec-digs.dp, 0))
+ }
+
+ // unknown format
+ return append(dst, '%', fmt)
+}
+
+// Round d (= mant * 2^exp) to the shortest number of digits
+// that will let the original floating point value be precisely
+// reconstructed. Size is original floating point size (64 or 32).
+func roundShortest(d *decimal, mant uint64, exp int, flt *floatInfo) {
+ // If mantissa is zero, the number is zero; stop now.
+ if mant == 0 {
+ d.nd = 0
+ return
+ }
+
+ // Compute upper and lower such that any decimal number
+ // between upper and lower (possibly inclusive)
+ // will round to the original floating point number.
+
+ // We may see at once that the number is already shortest.
+ //
+ // Suppose d is not denormal, so that 2^exp <= d < 10^dp.
+ // The closest shorter number is at least 10^(dp-nd) away.
+ // The lower/upper bounds computed below are at distance
+ // at most 2^(exp-mantbits).
+ //
+ // So the number is already shortest if 10^(dp-nd) > 2^(exp-mantbits),
+ // or equivalently log2(10)*(dp-nd) > exp-mantbits.
+ // It is true if 332/100*(dp-nd) >= exp-mantbits (log2(10) > 3.32).
+ minexp := flt.bias + 1 // minimum possible exponent
+ if exp > minexp && 332*(d.dp-d.nd) >= 100*(exp-int(flt.mantbits)) {
+ // The number is already shortest.
+ return
+ }
+
+ // d = mant << (exp - mantbits)
+ // Next highest floating point number is mant+1 << exp-mantbits.
+ // Our upper bound is halfway between, mant*2+1 << exp-mantbits-1.
+ upper := new(decimal)
+ upper.Assign(mant*2 + 1)
+ upper.Shift(exp - int(flt.mantbits) - 1)
+
+ // d = mant << (exp - mantbits)
+ // Next lowest floating point number is mant-1 << exp-mantbits,
+ // unless mant-1 drops the significant bit and exp is not the minimum exp,
+ // in which case the next lowest is mant*2-1 << exp-mantbits-1.
+ // Either way, call it mantlo << explo-mantbits.
+ // Our lower bound is halfway between, mantlo*2+1 << explo-mantbits-1.
+ var mantlo uint64
+ var explo int
+ if mant > 1<<flt.mantbits || exp == minexp {
+ mantlo = mant - 1
+ explo = exp
+ } else {
+ mantlo = mant*2 - 1
+ explo = exp - 1
+ }
+ lower := new(decimal)
+ lower.Assign(mantlo*2 + 1)
+ lower.Shift(explo - int(flt.mantbits) - 1)
+
+ // The upper and lower bounds are possible outputs only if
+ // the original mantissa is even, so that IEEE round-to-even
+ // would round to the original mantissa and not the neighbors.
+ inclusive := mant%2 == 0
+
+ // Now we can figure out the minimum number of digits required.
+ // Walk along until d has distinguished itself from upper and lower.
+ for i := 0; i < d.nd; i++ {
+ var l, m, u byte // lower, middle, upper digits
+ if i < lower.nd {
+ l = lower.d[i]
+ } else {
+ l = '0'
+ }
+ m = d.d[i]
+ if i < upper.nd {
+ u = upper.d[i]
+ } else {
+ u = '0'
+ }
+
+ // Okay to round down (truncate) if lower has a different digit
+ // or if lower is inclusive and is exactly the result of rounding down.
+ okdown := l != m || (inclusive && l == m && i+1 == lower.nd)
+
+ // Okay to round up if upper has a different digit and
+ // either upper is inclusive or upper is bigger than the result of rounding up.
+ okup := m != u && (inclusive || m+1 < u || i+1 < upper.nd)
+
+ // If it's okay to do either, then round to the nearest one.
+ // If it's okay to do only one, do it.
+ switch {
+ case okdown && okup:
+ d.Round(i + 1)
+ return
+ case okdown:
+ d.RoundDown(i + 1)
+ return
+ case okup:
+ d.RoundUp(i + 1)
+ return
+ }
+ }
+}
+
+type decimalSlice struct {
+ d []byte
+ nd, dp int
+ neg bool
+}
+
+// %e: -d.ddddde±dd
+func fmtE(dst []byte, neg bool, d decimalSlice, prec int, fmt byte) []byte {
+ // sign
+ if neg {
+ dst = append(dst, '-')
+ }
+
+ // first digit
+ ch := byte('0')
+ if d.nd != 0 {
+ ch = d.d[0]
+ }
+ dst = append(dst, ch)
+
+ // .moredigits
+ if prec > 0 {
+ dst = append(dst, '.')
+ i := 1
+ m := d.nd + prec + 1 - max(d.nd, prec+1)
+ for i < m {
+ dst = append(dst, d.d[i])
+ i++
+ }
+ for i <= prec {
+ dst = append(dst, '0')
+ i++
+ }
+ }
+
+ // e±
+ dst = append(dst, fmt)
+ exp := d.dp - 1
+ if d.nd == 0 { // special case: 0 has exponent 0
+ exp = 0
+ }
+ if exp < 0 {
+ ch = '-'
+ exp = -exp
+ } else {
+ ch = '+'
+ }
+ dst = append(dst, ch)
+
+ // dddd
+ var buf [3]byte
+ i := len(buf)
+ for exp >= 10 {
+ i--
+ buf[i] = byte(exp%10 + '0')
+ exp /= 10
+ }
+ // exp < 10
+ i--
+ buf[i] = byte(exp + '0')
+
+ switch i {
+ case 0:
+ dst = append(dst, buf[0], buf[1], buf[2])
+ case 1:
+ dst = append(dst, buf[1], buf[2])
+ case 2:
+ // leading zeroes
+ dst = append(dst, '0', buf[2])
+ }
+ return dst
+}
+
+// %f: -ddddddd.ddddd
+func fmtF(dst []byte, neg bool, d decimalSlice, prec int) []byte {
+ // sign
+ if neg {
+ dst = append(dst, '-')
+ }
+
+ // integer, padded with zeros as needed.
+ if d.dp > 0 {
+ var i int
+ for i = 0; i < d.dp && i < d.nd; i++ {
+ dst = append(dst, d.d[i])
+ }
+ for ; i < d.dp; i++ {
+ dst = append(dst, '0')
+ }
+ } else {
+ dst = append(dst, '0')
+ }
+
+ // fraction
+ if prec > 0 {
+ dst = append(dst, '.')
+ for i := 0; i < prec; i++ {
+ ch := byte('0')
+ if j := d.dp + i; 0 <= j && j < d.nd {
+ ch = d.d[j]
+ }
+ dst = append(dst, ch)
+ }
+ }
+
+ return dst
+}
+
+// %b: -ddddddddp+ddd
+func fmtB(dst []byte, neg bool, mant uint64, exp int, flt *floatInfo) []byte {
+ var buf [50]byte
+ w := len(buf)
+ exp -= int(flt.mantbits)
+ esign := byte('+')
+ if exp < 0 {
+ esign = '-'
+ exp = -exp
+ }
+ n := 0
+ for exp > 0 || n < 1 {
+ n++
+ w--
+ buf[w] = byte(exp%10 + '0')
+ exp /= 10
+ }
+ w--
+ buf[w] = esign
+ w--
+ buf[w] = 'p'
+ n = 0
+ for mant > 0 || n < 1 {
+ n++
+ w--
+ buf[w] = byte(mant%10 + '0')
+ mant /= 10
+ }
+ if neg {
+ w--
+ buf[w] = '-'
+ }
+ return append(dst, buf[w:]...)
+}
+
+func max(a, b int) int {
+ if a > b {
+ return a
+ }
+ return b
+}