type SelectCase(struct)
A SelectCase describes a single case in a select operation.
The kind of case depends on Dir, the communication direction.
If Dir is SelectDefault, the case represents a default case.
Chan and Send must be zero Values.
If Dir is SelectSend, the case represents a send operation.
Normally Chan's underlying value must be a channel, and Send's underlying value must be
assignable to the channel's element type. As a special case, if Chan is a zero Value,
then the case is ignored, and the field Send will also be ignored and may be either zero
or non-zero.
If Dir is SelectRecv, the case represents a receive operation.
Normally Chan's underlying value must be a channel and Send must be a zero Value.
If Chan is a zero Value, then the case is ignored, but Send must still be a zero Value.
When a receive operation is selected, the received Value is returned by Select.
ChanValueDirSelectDirSendValue
func Select(cases []SelectCase) (chosen int, recv Value, recvOK bool)
type SliceHeader(struct)
SliceHeader is the runtime representation of a slice.
It cannot be used safely or portably and its representation may
change in a later release.
Moreover, the Data field is not sufficient to guarantee the data
it references will not be garbage collected, so programs must keep
a separate, correctly typed pointer to the underlying data.
CapintDatauintptrLenint
type StringHeader(struct)
StringHeader is the runtime representation of a string.
It cannot be used safely or portably and its representation may
change in a later release.
Moreover, the Data field is not sufficient to guarantee the data
it references will not be garbage collected, so programs must keep
a separate, correctly typed pointer to the underlying data.
DatauintptrLenint
type StructTagstring
A StructTag is the tag string in a struct field.
By convention, tag strings are a concatenation of
optionally space-separated key:"value" pairs.
Each key is a non-empty string consisting of non-control
characters other than space (U+0020 ' '), quote (U+0022 '"'),
and colon (U+003A ':'). Each value is quoted using U+0022 '"'
characters and Go string literal syntax.
(T) Get(key string) string
(T) Lookup(key string) (value string, ok bool)
type ValueError(struct)
A ValueError occurs when a Value method is invoked on
a Value that does not support it. Such cases are documented
in the description of each method.
KindKindMethodstring
(*T) Error() string
*T : error
Exported Values
func Append(s Value, x ...Value) Value
Append appends the values x to a slice s and returns the resulting slice.
As in Go, each x's value must be assignable to the slice's element type.
func AppendSlice(s, t Value) Value
AppendSlice appends a slice t to a slice s and returns the resulting slice.
The slices s and t must have the same element type.
func ArrayOf(count int, elem Type) Type
ArrayOf returns the array type with the given count and element type.
For example, if t represents int, ArrayOf(5, t) represents [5]int.
If the resulting type would be larger than the available address space,
ArrayOf panics.
func ChanOf(dir ChanDir, t Type) Type
ChanOf returns the channel type with the given direction and element type.
For example, if t represents int, ChanOf(RecvDir, t) represents <-chan int.
The gc runtime imposes a limit of 64 kB on channel element types.
If t's size is equal to or exceeds this limit, ChanOf panics.
func Copy(dst, src Value) int
Copy copies the contents of src into dst until either
dst has been filled or src has been exhausted.
It returns the number of elements copied.
Dst and src each must have kind Slice or Array, and
dst and src must have the same element type.
As a special case, src can have kind String if the element type of dst is kind Uint8.
func DeepEqual(x, y interface{}) bool
DeepEqual reports whether x and y are ``deeply equal,'' defined as follows.
Two values of identical type are deeply equal if one of the following cases applies.
Values of distinct types are never deeply equal.
Array values are deeply equal when their corresponding elements are deeply equal.
Struct values are deeply equal if their corresponding fields,
both exported and unexported, are deeply equal.
Func values are deeply equal if both are nil; otherwise they are not deeply equal.
Interface values are deeply equal if they hold deeply equal concrete values.
Map values are deeply equal when all of the following are true:
they are both nil or both non-nil, they have the same length,
and either they are the same map object or their corresponding keys
(matched using Go equality) map to deeply equal values.
Pointer values are deeply equal if they are equal using Go's == operator
or if they point to deeply equal values.
Slice values are deeply equal when all of the following are true:
they are both nil or both non-nil, they have the same length,
and either they point to the same initial entry of the same underlying array
(that is, &x[0] == &y[0]) or their corresponding elements (up to length) are deeply equal.
Note that a non-nil empty slice and a nil slice (for example, []byte{} and []byte(nil))
are not deeply equal.
Other values - numbers, bools, strings, and channels - are deeply equal
if they are equal using Go's == operator.
In general DeepEqual is a recursive relaxation of Go's == operator.
However, this idea is impossible to implement without some inconsistency.
Specifically, it is possible for a value to be unequal to itself,
either because it is of func type (uncomparable in general)
or because it is a floating-point NaN value (not equal to itself in floating-point comparison),
or because it is an array, struct, or interface containing
such a value.
On the other hand, pointer values are always equal to themselves,
even if they point at or contain such problematic values,
because they compare equal using Go's == operator, and that
is a sufficient condition to be deeply equal, regardless of content.
DeepEqual has been defined so that the same short-cut applies
to slices and maps: if x and y are the same slice or the same map,
they are deeply equal regardless of content.
As DeepEqual traverses the data values it may find a cycle. The
second and subsequent times that DeepEqual compares two pointer
values that have been compared before, it treats the values as
equal rather than examining the values to which they point.
This ensures that DeepEqual terminates.
func FuncOf(in, out []Type, variadic bool) Type
FuncOf returns the function type with the given argument and result types.
For example if k represents int and e represents string,
FuncOf([]Type{k}, []Type{e}, false) represents func(int) string.
The variadic argument controls whether the function is variadic. FuncOf
panics if the in[len(in)-1] does not represent a slice and variadic is
true.
func Indirect(v Value) Value
Indirect returns the value that v points to.
If v is a nil pointer, Indirect returns a zero Value.
If v is not a pointer, Indirect returns v.
func MakeChan(typ Type, buffer int) Value
MakeChan creates a new channel with the specified type and buffer size.
func MakeFunc(typ Type, fn func(args []Value) (results []Value)) Value
MakeFunc returns a new function of the given Type
that wraps the function fn. When called, that new function
does the following:
- converts its arguments to a slice of Values.
- runs results := fn(args).
- returns the results as a slice of Values, one per formal result.
The implementation fn can assume that the argument Value slice
has the number and type of arguments given by typ.
If typ describes a variadic function, the final Value is itself
a slice representing the variadic arguments, as in the
body of a variadic function. The result Value slice returned by fn
must have the number and type of results given by typ.
The Value.Call method allows the caller to invoke a typed function
in terms of Values; in contrast, MakeFunc allows the caller to implement
a typed function in terms of Values.
The Examples section of the documentation includes an illustration
of how to use MakeFunc to build a swap function for different types.
func MakeMap(typ Type) Value
MakeMap creates a new map with the specified type.
func MakeMapWithSize(typ Type, n int) Value
MakeMapWithSize creates a new map with the specified type
and initial space for approximately n elements.
func MakeSlice(typ Type, len, cap int) Value
MakeSlice creates a new zero-initialized slice value
for the specified slice type, length, and capacity.
func MapOf(key, elem Type) Type
MapOf returns the map type with the given key and element types.
For example, if k represents int and e represents string,
MapOf(k, e) represents map[int]string.
If the key type is not a valid map key type (that is, if it does
not implement Go's == operator), MapOf panics.
func New(typ Type) Value
New returns a Value representing a pointer to a new zero value
for the specified type. That is, the returned Value's Type is PtrTo(typ).
func NewAt(typ Type, p unsafe.Pointer) Value
NewAt returns a Value representing a pointer to a value of the
specified type, using p as that pointer.
func Select(cases []SelectCase) (chosen int, recv Value, recvOK bool)
Select executes a select operation described by the list of cases.
Like the Go select statement, it blocks until at least one of the cases
can proceed, makes a uniform pseudo-random choice,
and then executes that case. It returns the index of the chosen case
and, if that case was a receive operation, the value received and a
boolean indicating whether the value corresponds to a send on the channel
(as opposed to a zero value received because the channel is closed).
Select supports a maximum of 65536 cases.
func StructOf(fields []StructField) Type
StructOf returns the struct type containing fields.
The Offset and Index fields are ignored and computed as they would be
by the compiler.
StructOf currently does not generate wrapper methods for embedded
fields and panics if passed unexported StructFields.
These limitations may be lifted in a future version.
func Swapper(slice interface{}) func(i, j int)
Swapper returns a function that swaps the elements in the provided
slice.
Swapper panics if the provided interface is not a slice.
func TypeOf(i interface{}) Type
TypeOf returns the reflection Type that represents the dynamic type of i.
If i is a nil interface value, TypeOf returns nil.
func ValueOf(i interface{}) Value
ValueOf returns a new Value initialized to the concrete value
stored in the interface i. ValueOf(nil) returns the zero Value.
func Zero(typ Type) Value
Zero returns a Value representing the zero value for the specified type.
The result is different from the zero value of the Value struct,
which represents no value at all.
For example, Zero(TypeOf(42)) returns a Value with Kind Int and value 0.
The returned value is neither addressable nor settable.
The pages are generated with Goldsv0.1.6. (GOOS=darwin GOARCH=amd64)
Golds is a Go 101 project and developed by Tapir Liu.
PR and bug reports are welcome and can be submitted to the issue list.
Please follow @Go100and1 (reachable from the left QR code) to get the latest news of Golds.
