diff options
Diffstat (limited to 'vendor/github.com/google/go-cmp/cmp/path.go')
| -rw-r--r-- | vendor/github.com/google/go-cmp/cmp/path.go | 378 |
1 files changed, 0 insertions, 378 deletions
diff --git a/vendor/github.com/google/go-cmp/cmp/path.go b/vendor/github.com/google/go-cmp/cmp/path.go deleted file mode 100644 index c71003463..000000000 --- a/vendor/github.com/google/go-cmp/cmp/path.go +++ /dev/null @@ -1,378 +0,0 @@ -// Copyright 2017, 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 cmp - -import ( - "fmt" - "reflect" - "strings" - "unicode" - "unicode/utf8" - - "github.com/google/go-cmp/cmp/internal/value" -) - -// Path is a list of PathSteps describing the sequence of operations to get -// from some root type to the current position in the value tree. -// The first Path element is always an operation-less PathStep that exists -// simply to identify the initial type. -// -// When traversing structs with embedded structs, the embedded struct will -// always be accessed as a field before traversing the fields of the -// embedded struct themselves. That is, an exported field from the -// embedded struct will never be accessed directly from the parent struct. -type Path []PathStep - -// PathStep is a union-type for specific operations to traverse -// a value's tree structure. Users of this package never need to implement -// these types as values of this type will be returned by this package. -// -// Implementations of this interface are -// StructField, SliceIndex, MapIndex, Indirect, TypeAssertion, and Transform. -type PathStep interface { - String() string - - // Type is the resulting type after performing the path step. - Type() reflect.Type - - // Values is the resulting values after performing the path step. - // The type of each valid value is guaranteed to be identical to Type. - // - // In some cases, one or both may be invalid or have restrictions: - // • For StructField, both are not interface-able if the current field - // is unexported and the struct type is not explicitly permitted by - // an Exporter to traverse unexported fields. - // • For SliceIndex, one may be invalid if an element is missing from - // either the x or y slice. - // • For MapIndex, one may be invalid if an entry is missing from - // either the x or y map. - // - // The provided values must not be mutated. - Values() (vx, vy reflect.Value) -} - -var ( - _ PathStep = StructField{} - _ PathStep = SliceIndex{} - _ PathStep = MapIndex{} - _ PathStep = Indirect{} - _ PathStep = TypeAssertion{} - _ PathStep = Transform{} -) - -func (pa *Path) push(s PathStep) { - *pa = append(*pa, s) -} - -func (pa *Path) pop() { - *pa = (*pa)[:len(*pa)-1] -} - -// Last returns the last PathStep in the Path. -// If the path is empty, this returns a non-nil PathStep that reports a nil Type. -func (pa Path) Last() PathStep { - return pa.Index(-1) -} - -// Index returns the ith step in the Path and supports negative indexing. -// A negative index starts counting from the tail of the Path such that -1 -// refers to the last step, -2 refers to the second-to-last step, and so on. -// If index is invalid, this returns a non-nil PathStep that reports a nil Type. -func (pa Path) Index(i int) PathStep { - if i < 0 { - i = len(pa) + i - } - if i < 0 || i >= len(pa) { - return pathStep{} - } - return pa[i] -} - -// String returns the simplified path to a node. -// The simplified path only contains struct field accesses. -// -// For example: -// MyMap.MySlices.MyField -func (pa Path) String() string { - var ss []string - for _, s := range pa { - if _, ok := s.(StructField); ok { - ss = append(ss, s.String()) - } - } - return strings.TrimPrefix(strings.Join(ss, ""), ".") -} - -// GoString returns the path to a specific node using Go syntax. -// -// For example: -// (*root.MyMap["key"].(*mypkg.MyStruct).MySlices)[2][3].MyField -func (pa Path) GoString() string { - var ssPre, ssPost []string - var numIndirect int - for i, s := range pa { - var nextStep PathStep - if i+1 < len(pa) { - nextStep = pa[i+1] - } - switch s := s.(type) { - case Indirect: - numIndirect++ - pPre, pPost := "(", ")" - switch nextStep.(type) { - case Indirect: - continue // Next step is indirection, so let them batch up - case StructField: - numIndirect-- // Automatic indirection on struct fields - case nil: - pPre, pPost = "", "" // Last step; no need for parenthesis - } - if numIndirect > 0 { - ssPre = append(ssPre, pPre+strings.Repeat("*", numIndirect)) - ssPost = append(ssPost, pPost) - } - numIndirect = 0 - continue - case Transform: - ssPre = append(ssPre, s.trans.name+"(") - ssPost = append(ssPost, ")") - continue - } - ssPost = append(ssPost, s.String()) - } - for i, j := 0, len(ssPre)-1; i < j; i, j = i+1, j-1 { - ssPre[i], ssPre[j] = ssPre[j], ssPre[i] - } - return strings.Join(ssPre, "") + strings.Join(ssPost, "") -} - -type pathStep struct { - typ reflect.Type - vx, vy reflect.Value -} - -func (ps pathStep) Type() reflect.Type { return ps.typ } -func (ps pathStep) Values() (vx, vy reflect.Value) { return ps.vx, ps.vy } -func (ps pathStep) String() string { - if ps.typ == nil { - return "<nil>" - } - s := ps.typ.String() - if s == "" || strings.ContainsAny(s, "{}\n") { - return "root" // Type too simple or complex to print - } - return fmt.Sprintf("{%s}", s) -} - -// StructField represents a struct field access on a field called Name. -type StructField struct{ *structField } -type structField struct { - pathStep - name string - idx int - - // These fields are used for forcibly accessing an unexported field. - // pvx, pvy, and field are only valid if unexported is true. - unexported bool - mayForce bool // Forcibly allow visibility - paddr bool // Was parent addressable? - pvx, pvy reflect.Value // Parent values (always addressable) - field reflect.StructField // Field information -} - -func (sf StructField) Type() reflect.Type { return sf.typ } -func (sf StructField) Values() (vx, vy reflect.Value) { - if !sf.unexported { - return sf.vx, sf.vy // CanInterface reports true - } - - // Forcibly obtain read-write access to an unexported struct field. - if sf.mayForce { - vx = retrieveUnexportedField(sf.pvx, sf.field, sf.paddr) - vy = retrieveUnexportedField(sf.pvy, sf.field, sf.paddr) - return vx, vy // CanInterface reports true - } - return sf.vx, sf.vy // CanInterface reports false -} -func (sf StructField) String() string { return fmt.Sprintf(".%s", sf.name) } - -// Name is the field name. -func (sf StructField) Name() string { return sf.name } - -// Index is the index of the field in the parent struct type. -// See reflect.Type.Field. -func (sf StructField) Index() int { return sf.idx } - -// SliceIndex is an index operation on a slice or array at some index Key. -type SliceIndex struct{ *sliceIndex } -type sliceIndex struct { - pathStep - xkey, ykey int - isSlice bool // False for reflect.Array -} - -func (si SliceIndex) Type() reflect.Type { return si.typ } -func (si SliceIndex) Values() (vx, vy reflect.Value) { return si.vx, si.vy } -func (si SliceIndex) String() string { - switch { - case si.xkey == si.ykey: - return fmt.Sprintf("[%d]", si.xkey) - case si.ykey == -1: - // [5->?] means "I don't know where X[5] went" - return fmt.Sprintf("[%d->?]", si.xkey) - case si.xkey == -1: - // [?->3] means "I don't know where Y[3] came from" - return fmt.Sprintf("[?->%d]", si.ykey) - default: - // [5->3] means "X[5] moved to Y[3]" - return fmt.Sprintf("[%d->%d]", si.xkey, si.ykey) - } -} - -// Key is the index key; it may return -1 if in a split state -func (si SliceIndex) Key() int { - if si.xkey != si.ykey { - return -1 - } - return si.xkey -} - -// SplitKeys are the indexes for indexing into slices in the -// x and y values, respectively. These indexes may differ due to the -// insertion or removal of an element in one of the slices, causing -// all of the indexes to be shifted. If an index is -1, then that -// indicates that the element does not exist in the associated slice. -// -// Key is guaranteed to return -1 if and only if the indexes returned -// by SplitKeys are not the same. SplitKeys will never return -1 for -// both indexes. -func (si SliceIndex) SplitKeys() (ix, iy int) { return si.xkey, si.ykey } - -// MapIndex is an index operation on a map at some index Key. -type MapIndex struct{ *mapIndex } -type mapIndex struct { - pathStep - key reflect.Value -} - -func (mi MapIndex) Type() reflect.Type { return mi.typ } -func (mi MapIndex) Values() (vx, vy reflect.Value) { return mi.vx, mi.vy } -func (mi MapIndex) String() string { return fmt.Sprintf("[%#v]", mi.key) } - -// Key is the value of the map key. -func (mi MapIndex) Key() reflect.Value { return mi.key } - -// Indirect represents pointer indirection on the parent type. -type Indirect struct{ *indirect } -type indirect struct { - pathStep -} - -func (in Indirect) Type() reflect.Type { return in.typ } -func (in Indirect) Values() (vx, vy reflect.Value) { return in.vx, in.vy } -func (in Indirect) String() string { return "*" } - -// TypeAssertion represents a type assertion on an interface. -type TypeAssertion struct{ *typeAssertion } -type typeAssertion struct { - pathStep -} - -func (ta TypeAssertion) Type() reflect.Type { return ta.typ } -func (ta TypeAssertion) Values() (vx, vy reflect.Value) { return ta.vx, ta.vy } -func (ta TypeAssertion) String() string { return fmt.Sprintf(".(%v)", ta.typ) } - -// Transform is a transformation from the parent type to the current type. -type Transform struct{ *transform } -type transform struct { - pathStep - trans *transformer -} - -func (tf Transform) Type() reflect.Type { return tf.typ } -func (tf Transform) Values() (vx, vy reflect.Value) { return tf.vx, tf.vy } -func (tf Transform) String() string { return fmt.Sprintf("%s()", tf.trans.name) } - -// Name is the name of the Transformer. -func (tf Transform) Name() string { return tf.trans.name } - -// Func is the function pointer to the transformer function. -func (tf Transform) Func() reflect.Value { return tf.trans.fnc } - -// Option returns the originally constructed Transformer option. -// The == operator can be used to detect the exact option used. -func (tf Transform) Option() Option { return tf.trans } - -// pointerPath represents a dual-stack of pointers encountered when -// recursively traversing the x and y values. This data structure supports -// detection of cycles and determining whether the cycles are equal. -// In Go, cycles can occur via pointers, slices, and maps. -// -// The pointerPath uses a map to represent a stack; where descension into a -// pointer pushes the address onto the stack, and ascension from a pointer -// pops the address from the stack. Thus, when traversing into a pointer from -// reflect.Ptr, reflect.Slice element, or reflect.Map, we can detect cycles -// by checking whether the pointer has already been visited. The cycle detection -// uses a separate stack for the x and y values. -// -// If a cycle is detected we need to determine whether the two pointers -// should be considered equal. The definition of equality chosen by Equal -// requires two graphs to have the same structure. To determine this, both the -// x and y values must have a cycle where the previous pointers were also -// encountered together as a pair. -// -// Semantically, this is equivalent to augmenting Indirect, SliceIndex, and -// MapIndex with pointer information for the x and y values. -// Suppose px and py are two pointers to compare, we then search the -// Path for whether px was ever encountered in the Path history of x, and -// similarly so with py. If either side has a cycle, the comparison is only -// equal if both px and py have a cycle resulting from the same PathStep. -// -// Using a map as a stack is more performant as we can perform cycle detection -// in O(1) instead of O(N) where N is len(Path). -type pointerPath struct { - // mx is keyed by x pointers, where the value is the associated y pointer. - mx map[value.Pointer]value.Pointer - // my is keyed by y pointers, where the value is the associated x pointer. - my map[value.Pointer]value.Pointer -} - -func (p *pointerPath) Init() { - p.mx = make(map[value.Pointer]value.Pointer) - p.my = make(map[value.Pointer]value.Pointer) -} - -// Push indicates intent to descend into pointers vx and vy where -// visited reports whether either has been seen before. If visited before, -// equal reports whether both pointers were encountered together. -// Pop must be called if and only if the pointers were never visited. -// -// The pointers vx and vy must be a reflect.Ptr, reflect.Slice, or reflect.Map -// and be non-nil. -func (p pointerPath) Push(vx, vy reflect.Value) (equal, visited bool) { - px := value.PointerOf(vx) - py := value.PointerOf(vy) - _, ok1 := p.mx[px] - _, ok2 := p.my[py] - if ok1 || ok2 { - equal = p.mx[px] == py && p.my[py] == px // Pointers paired together - return equal, true - } - p.mx[px] = py - p.my[py] = px - return false, false -} - -// Pop ascends from pointers vx and vy. -func (p pointerPath) Pop(vx, vy reflect.Value) { - delete(p.mx, value.PointerOf(vx)) - delete(p.my, value.PointerOf(vy)) -} - -// isExported reports whether the identifier is exported. -func isExported(id string) bool { - r, _ := utf8.DecodeRuneInString(id) - return unicode.IsUpper(r) -} |