diff options
author | Jesse Duffield <jessedduffield@gmail.com> | 2018-08-11 15:50:42 +1000 |
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committer | GitHub <noreply@github.com> | 2018-08-11 15:50:42 +1000 |
commit | aec125df7042dd88ad402a819ab1285031250474 (patch) | |
tree | a0590e78eb5d0c12ebde0a7fc012e2c6e2d985f9 /vendor/github.com/davecgh/go-spew/spew/common.go | |
parent | bf9a53fada5b4d72f3e3b0a8877ab845867137df (diff) | |
parent | 9626ebdf3577090cff24fab82880fe9d330adb59 (diff) |
Merge branch 'master' into add-void-readme
Diffstat (limited to 'vendor/github.com/davecgh/go-spew/spew/common.go')
-rw-r--r-- | vendor/github.com/davecgh/go-spew/spew/common.go | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/vendor/github.com/davecgh/go-spew/spew/common.go b/vendor/github.com/davecgh/go-spew/spew/common.go new file mode 100644 index 000000000..7c519ff47 --- /dev/null +++ b/vendor/github.com/davecgh/go-spew/spew/common.go @@ -0,0 +1,341 @@ +/* + * Copyright (c) 2013-2016 Dave Collins <dave@davec.name> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +package spew + +import ( + "bytes" + "fmt" + "io" + "reflect" + "sort" + "strconv" +) + +// Some constants in the form of bytes to avoid string overhead. This mirrors +// the technique used in the fmt package. +var ( + panicBytes = []byte("(PANIC=") + plusBytes = []byte("+") + iBytes = []byte("i") + trueBytes = []byte("true") + falseBytes = []byte("false") + interfaceBytes = []byte("(interface {})") + commaNewlineBytes = []byte(",\n") + newlineBytes = []byte("\n") + openBraceBytes = []byte("{") + openBraceNewlineBytes = []byte("{\n") + closeBraceBytes = []byte("}") + asteriskBytes = []byte("*") + colonBytes = []byte(":") + colonSpaceBytes = []byte(": ") + openParenBytes = []byte("(") + closeParenBytes = []byte(")") + spaceBytes = []byte(" ") + pointerChainBytes = []byte("->") + nilAngleBytes = []byte("<nil>") + maxNewlineBytes = []byte("<max depth reached>\n") + maxShortBytes = []byte("<max>") + circularBytes = []byte("<already shown>") + circularShortBytes = []byte("<shown>") + invalidAngleBytes = []byte("<invalid>") + openBracketBytes = []byte("[") + closeBracketBytes = []byte("]") + percentBytes = []byte("%") + precisionBytes = []byte(".") + openAngleBytes = []byte("<") + closeAngleBytes = []byte(">") + openMapBytes = []byte("map[") + closeMapBytes = []byte("]") + lenEqualsBytes = []byte("len=") + capEqualsBytes = []byte("cap=") +) + +// hexDigits is used to map a decimal value to a hex digit. +var hexDigits = "0123456789abcdef" + +// catchPanic handles any panics that might occur during the handleMethods +// calls. +func catchPanic(w io.Writer, v reflect.Value) { + if err := recover(); err != nil { + w.Write(panicBytes) + fmt.Fprintf(w, "%v", err) + w.Write(closeParenBytes) + } +} + +// handleMethods attempts to call the Error and String methods on the underlying +// type the passed reflect.Value represents and outputes the result to Writer w. +// +// It handles panics in any called methods by catching and displaying the error +// as the formatted value. +func handleMethods(cs *ConfigState, w io.Writer, v reflect.Value) (handled bool) { + // We need an interface to check if the type implements the error or + // Stringer interface. However, the reflect package won't give us an + // interface on certain things like unexported struct fields in order + // to enforce visibility rules. We use unsafe, when it's available, + // to bypass these restrictions since this package does not mutate the + // values. + if !v.CanInterface() { + if UnsafeDisabled { + return false + } + + v = unsafeReflectValue(v) + } + + // Choose whether or not to do error and Stringer interface lookups against + // the base type or a pointer to the base type depending on settings. + // Technically calling one of these methods with a pointer receiver can + // mutate the value, however, types which choose to satisify an error or + // Stringer interface with a pointer receiver should not be mutating their + // state inside these interface methods. + if !cs.DisablePointerMethods && !UnsafeDisabled && !v.CanAddr() { + v = unsafeReflectValue(v) + } + if v.CanAddr() { + v = v.Addr() + } + + // Is it an error or Stringer? + switch iface := v.Interface().(type) { + case error: + defer catchPanic(w, v) + if cs.ContinueOnMethod { + w.Write(openParenBytes) + w.Write([]byte(iface.Error())) + w.Write(closeParenBytes) + w.Write(spaceBytes) + return false + } + + w.Write([]byte(iface.Error())) + return true + + case fmt.Stringer: + defer catchPanic(w, v) + if cs.ContinueOnMethod { + w.Write(openParenBytes) + w.Write([]byte(iface.String())) + w.Write(closeParenBytes) + w.Write(spaceBytes) + return false + } + w.Write([]byte(iface.String())) + return true + } + return false +} + +// printBool outputs a boolean value as true or false to Writer w. +func printBool(w io.Writer, val bool) { + if val { + w.Write(trueBytes) + } else { + w.Write(falseBytes) + } +} + +// printInt outputs a signed integer value to Writer w. +func printInt(w io.Writer, val int64, base int) { + w.Write([]byte(strconv.FormatInt(val, base))) +} + +// printUint outputs an unsigned integer value to Writer w. +func printUint(w io.Writer, val uint64, base int) { + w.Write([]byte(strconv.FormatUint(val, base))) +} + +// printFloat outputs a floating point value using the specified precision, +// which is expected to be 32 or 64bit, to Writer w. +func printFloat(w io.Writer, val float64, precision int) { + w.Write([]byte(strconv.FormatFloat(val, 'g', -1, precision))) +} + +// printComplex outputs a complex value using the specified float precision +// for the real and imaginary parts to Writer w. +func printComplex(w io.Writer, c complex128, floatPrecision int) { + r := real(c) + w.Write(openParenBytes) + w.Write([]byte(strconv.FormatFloat(r, 'g', -1, floatPrecision))) + i := imag(c) + if i >= 0 { + w.Write(plusBytes) + } + w.Write([]byte(strconv.FormatFloat(i, 'g', -1, floatPrecision))) + w.Write(iBytes) + w.Write(closeParenBytes) +} + +// printHexPtr outputs a uintptr formatted as hexidecimal with a leading '0x' +// prefix to Writer w. +func printHexPtr(w io.Writer, p uintptr) { + // Null pointer. + num := uint64(p) + if num == 0 { + w.Write(nilAngleBytes) + return + } + + // Max uint64 is 16 bytes in hex + 2 bytes for '0x' prefix + buf := make([]byte, 18) + + // It's simpler to construct the hex string right to left. + base := uint64(16) + i := len(buf) - 1 + for num >= base { + buf[i] = hexDigits[num%base] + num /= base + i-- + } + buf[i] = hexDigits[num] + + // Add '0x' prefix. + i-- + buf[i] = 'x' + i-- + buf[i] = '0' + + // Strip unused leading bytes. + buf = buf[i:] + w.Write(buf) +} + +// valuesSorter implements sort.Interface to allow a slice of reflect.Value +// elements to be sorted. +type valuesSorter struct { + values []reflect.Value + strings []string // either nil or same len and values + cs *ConfigState +} + +// newValuesSorter initializes a valuesSorter instance, which holds a set of +// surrogate keys on which the data should be sorted. It uses flags in +// ConfigState to decide if and how to populate those surrogate keys. +func newValuesSorter(values []reflect.Value, cs *ConfigState) sort.Interface { + vs := &valuesSorter{values: values, cs: cs} + if canSortSimply(vs.values[0].Kind()) { + return vs + } + if !cs.DisableMethods { + vs.strings = make([]string, len(values)) + for i := range vs.values { + b := bytes.Buffer{} + if !handleMethods(cs, &b, vs.values[i]) { + vs.strings = nil + break + } + vs.strings[i] = b.String() + } + } + if vs.strings == nil && cs.SpewKeys { + vs.strings = make([]string, len(values)) + for i := range vs.values { + vs.strings[i] = Sprintf("%#v", vs.values[i].Interface()) + } + } + return vs +} + +// canSortSimply tests whether a reflect.Kind is a primitive that can be sorted +// directly, or whether it should be considered for sorting by surrogate keys +// (if the ConfigState allows it). +func canSortSimply(kind reflect.Kind) bool { + // This switch parallels valueSortLess, except for the default case. + switch kind { + case reflect.Bool: + return true + case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int: + return true + case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint: + return true + case reflect.Float32, reflect.Float64: + return true + case reflect.String: + return true + case reflect.Uintptr: + return true + case reflect.Array: + return true + } + return false +} + +// Len returns the number of values in the slice. It is part of the +// sort.Interface implementation. +func (s *valuesSorter) Len() int { + return len(s.values) +} + +// Swap swaps the values at the passed indices. It is part of the +// sort.Interface implementation. +func (s *valuesSorter) Swap(i, j int) { + s.values[i], s.values[j] = s.values[j], s.values[i] + if s.strings != nil { + s.strings[i], s.strings[j] = s.strings[j], s.strings[i] + } +} + +// valueSortLess returns whether the first value should sort before the second +// value. It is used by valueSorter.Less as part of the sort.Interface +// implementation. +func valueSortLess(a, b reflect.Value) bool { + switch a.Kind() { + case reflect.Bool: + return !a.Bool() && b.Bool() + case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int: + return a.Int() < b.Int() + case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint: + return a.Uint() < b.Uint() + case reflect.Float32, reflect.Float64: + return a.Float() < b.Float() + case reflect.String: + return a.String() < b.String() + case reflect.Uintptr: + return a.Uint() < b.Uint() + case reflect.Array: + // Compare the contents of both arrays. + l := a.Len() + for i := 0; i < l; i++ { + av := a.Index(i) + bv := b.Index(i) + if av.Interface() == bv.Interface() { + continue + } + return valueSortLess(av, bv) + } + } + return a.String() < b.String() +} + +// Less returns whether the value at index i should sort before the +// value at index j. It is part of the sort.Interface implementation. +func (s *valuesSorter) Less(i, j int) bool { + if s.strings == nil { + return valueSortLess(s.values[i], s.values[j]) + } + return s.strings[i] < s.strings[j] +} + +// sortValues is a sort function that handles both native types and any type that +// can be converted to error or Stringer. Other inputs are sorted according to +// their Value.String() value to ensure display stability. +func sortValues(values []reflect.Value, cs *ConfigState) { + if len(values) == 0 { + return + } + sort.Sort(newValuesSorter(values, cs)) +} |