// Contains checks whether the underlying value (which must be of type struct, map,
// string, array or slice) contains of another Value (e. g. used to check
// whether a struct contains of a specific field or a map contains a specific key).
//
// Example:
// AsValue("Hello, World!").Contains(AsValue("World")) == true
func (v *Value) Contains(other *Value) bool {
switch v.getResolvedValue().Kind() {
case reflect.Struct:
fieldValue := v.getResolvedValue().FieldByName(other.String())
return fieldValue.IsValid()
case reflect.Map:
var mapValue reflect.Value
switch other.Interface().(type) {
case int:
mapValue = v.getResolvedValue().MapIndex(other.getResolvedValue())
case string:
mapValue = v.getResolvedValue().MapIndex(other.getResolvedValue())
default:
logf("Value.Contains() does not support lookup type '%s'\n", other.getResolvedValue().Kind().String())
return false
}
return mapValue.IsValid()
case reflect.String:
return strings.Contains(v.getResolvedValue().String(), other.String())
case reflect.Slice, reflect.Array:
for i := 0; i < v.getResolvedValue().Len(); i++ {
item := v.getResolvedValue().Index(i)
if other.Interface() == item.Interface() {
return true
}
}
return false
default:
logf("Value.Contains() not available for type: %s\n", v.getResolvedValue().Kind().String())
return false
}
}
func (q *Query) findPopulatePath(path string) {
parts := strings.Split(path, ".")
resultVal := reflect.ValueOf(q.parentStruct).Elem()
var refVal reflect.Value
partsLen := len(parts)
for i := 0; i < partsLen; i++ {
elem := parts[i]
if i == 0 {
refVal = resultVal.FieldByName(elem)
structTag, _ := resultVal.Type().FieldByName(elem)
q.popSchema = structTag.Tag.Get(q.z.modelTag)
} else if i == partsLen-1 {
structTag, _ := refVal.Type().FieldByName(elem)
q.popSchema = structTag.Tag.Get(q.z.modelTag)
refVal = refVal.FieldByName(elem)
} else {
//refVal = handleSlice(refVal, elem, path)
refVal = refVal.FieldByName(elem)
}
if !refVal.IsValid() {
panic("field `" + elem + "` not found in populate path `" + path + "`")
}
}
if refVal.Kind() == reflect.Slice {
q.isSlice = true
}
q.populateField = refVal.Interface()
}
// printValue is like printArg but starts with a reflect value, not an interface{} value.
func (p *pp) printValue(value reflect.Value, verb rune, plus, goSyntax bool, depth int) (wasString bool) {
if !value.IsValid() {
if verb == 'T' || verb == 'v' {
p.buf.Write(nilAngleBytes)
} else {
p.badVerb(verb)
}
return false
}
// Special processing considerations.
// %T (the value's type) and %p (its address) are special; we always do them first.
switch verb {
case 'T':
p.printArg(value.Type().String(), 's', false, false, 0)
return false
case 'p':
p.fmtPointer(value, verb, goSyntax)
return false
}
// Handle values with special methods.
// Call always, even when arg == nil, because handleMethods clears p.fmt.plus for us.
p.arg = nil // Make sure it's cleared, for safety.
if value.CanInterface() {
p.arg = value.Interface()
}
if isString, handled := p.handleMethods(verb, plus, goSyntax, depth); handled {
return isString
}
return p.printReflectValue(value, verb, plus, goSyntax, depth)
}
// bypassCanInterface returns a version of v that
// bypasses the CanInterface check.
func bypassCanInterface(v reflect.Value) reflect.Value {
if !v.IsValid() || v.CanInterface() {
return v
}
*flagField(&v) &^= flagRO
return v
}
// apply replaces each AST field x in val with f(x), returning val.
// To avoid extra conversions, f operates on the reflect.Value form.
func apply(f func(reflect.Value) reflect.Value, val reflect.Value) reflect.Value {
if !val.IsValid() {
return reflect.Value{}
}
// *ast.Objects introduce cycles and are likely incorrect after
// rewrite; don't follow them but replace with nil instead
if val.Type() == objectPtrType {
return objectPtrNil
}
// similarly for scopes: they are likely incorrect after a rewrite;
// replace them with nil
if val.Type() == scopePtrType {
return scopePtrNil
}
switch v := reflect.Indirect(val); v.Kind() {
case reflect.Slice:
for i := 0; i < v.Len(); i++ {
e := v.Index(i)
setValue(e, f(e))
}
case reflect.Struct:
for i := 0; i < v.NumField(); i++ {
e := v.Field(i)
setValue(e, f(e))
}
case reflect.Interface:
e := v.Elem()
setValue(v, f(e))
}
return val
}
func (d *decoder) sequence(n *node, out reflect.Value) (good bool) {
l := len(n.children)
var iface reflect.Value
switch out.Kind() {
case reflect.Slice:
out.Set(reflect.MakeSlice(out.Type(), l, l))
case reflect.Interface:
// No type hints. Will have to use a generic sequence.
iface = out
out = settableValueOf(make([]interface{}, l))
default:
d.terror(n, yaml_SEQ_TAG, out)
return false
}
et := out.Type().Elem()
j := 0
for i := 0; i < l; i++ {
e := reflect.New(et).Elem()
if ok := d.unmarshal(n.children[i], e); ok {
out.Index(j).Set(e)
j++
}
}
out.Set(out.Slice(0, j))
if iface.IsValid() {
iface.Set(out)
}
return true
}
// decodeValue decodes the data stream representing a value and stores it in val.
func (dec *Decoder) decodeValue(wireId typeId, val reflect.Value) {
defer catchError(&dec.err)
// If the value is nil, it means we should just ignore this item.
if !val.IsValid() {
dec.decodeIgnoredValue(wireId)
return
}
// Dereference down to the underlying type.
ut := userType(val.Type())
base := ut.base
var enginePtr **decEngine
enginePtr, dec.err = dec.getDecEnginePtr(wireId, ut)
if dec.err != nil {
return
}
engine := *enginePtr
if st := base; st.Kind() == reflect.Struct && ut.externalDec == 0 {
if engine.numInstr == 0 && st.NumField() > 0 && len(dec.wireType[wireId].StructT.Field) > 0 {
name := base.Name()
errorf("type mismatch: no fields matched compiling decoder for %s", name)
}
dec.decodeStruct(engine, ut, unsafeAddr(val), ut.indir)
} else {
dec.decodeSingle(engine, ut, unsafeAddr(val))
}
}
func (d *Decoder) decodeNull(v reflect.Value) error {
if v.IsValid() && v.CanSet() {
v.Set(reflect.Zero(v.Type()))
}
return nil
}
func hydrateValue(v reflect.Value, component *token) error {
if !v.IsValid() || v.Kind() != reflect.Ptr {
return utils.NewError(hydrateValue, "unmarshal target must be a valid pointer", v, nil)
}
// handle any encodable properties
if encoder, isprop := v.Interface().(properties.CanEncodeName); isprop {
if name, err := encoder.EncodeICalName(); err != nil {
return utils.NewError(hydrateValue, "unable to lookup property name", v, err)
} else if properties, found := component.properties[name]; !found || len(properties) == 0 {
return utils.NewError(hydrateValue, "no matching propery values found for "+string(name), v, nil)
} else if len(properties) > 1 {
return utils.NewError(hydrateValue, "more than one property value matches single property interface", v, nil)
} else {
return hydrateProperty(v, properties[0])
}
}
// handle components
vkind := dereferencePointerValue(v).Kind()
if tag, err := extractTagFromValue(v); err != nil {
return utils.NewError(hydrateValue, "unable to extract component tag", v, err)
} else if components, found := component.components[tag]; !found || len(components) == 0 {
msg := fmt.Sprintf("unable to find matching component for %s", tag)
return utils.NewError(hydrateValue, msg, v, nil)
} else if vkind == reflect.Array || vkind == reflect.Slice {
return hydrateComponents(v, components)
} else if len(components) > 1 {
return utils.NewError(hydrateValue, "non-array interface provided but more than one component found!", v, nil)
} else {
return hydrateComponent(v, components[0])
}
}
func valiadateCopyField(f reflect.StructField, sfv, dfv reflect.Value) error {
// check dst field is exists, if not valid move on
if !dfv.IsValid() {
return fmt.Errorf("Field: '%v', does not exists in dst", f.Name)
}
// check kind of src and dst, if doesn't match move on
if (sfv.Kind() != dfv.Kind()) && !isInterface(dfv) {
return fmt.Errorf("Field: '%v', src [%v] & dst [%v] kind didn't match",
f.Name,
sfv.Kind(),
dfv.Kind(),
)
}
// check type of src and dst, if doesn't match move on
sfvt := deepTypeOf(sfv)
dfvt := deepTypeOf(dfv)
if (sfvt != dfvt) && !isInterface(dfv) {
return fmt.Errorf("Field: '%v', src [%v] & dst [%v] type didn't match",
f.Name,
sfvt,
dfvt,
)
}
return nil
}
func (d *Decoder) parse(rv reflect.Value) {
if !rv.IsValid() {
// skip ahead since we cannot store
d.valueInterface()
return
}
anchor := string(d.event.anchor)
switch d.event.event_type {
case yaml_SEQUENCE_START_EVENT:
d.begin_anchor(anchor)
d.sequence(rv)
d.end_anchor(anchor)
case yaml_MAPPING_START_EVENT:
d.begin_anchor(anchor)
d.mapping(rv)
d.end_anchor(anchor)
case yaml_SCALAR_EVENT:
d.begin_anchor(anchor)
d.scalar(rv)
d.end_anchor(anchor)
case yaml_ALIAS_EVENT:
d.alias(rv)
case yaml_DOCUMENT_END_EVENT:
default:
d.error(&UnexpectedEventError{
Value: string(d.event.value),
EventType: d.event.event_type,
At: d.event.start_mark,
})
}
}
func (d *decoder) sequence(n *node, out reflect.Value) (good bool) {
if set := d.setter("!!seq", &out, &good); set != nil {
defer set()
}
var iface reflect.Value
if out.Kind() == reflect.Interface {
// No type hints. Will have to use a generic sequence.
iface = out
out = settableValueOf(make([]interface{}, 0))
}
if out.Kind() != reflect.Slice {
return false
}
et := out.Type().Elem()
l := len(n.children)
for i := 0; i < l; i++ {
e := reflect.New(et).Elem()
if ok := d.unmarshal(n.children[i], e); ok {
out.Set(reflect.Append(out, e))
}
}
if iface.IsValid() {
iface.Set(out)
}
return true
}
// tomlArrayType returns the element type of a TOML array. The type returned
// may be nil if it cannot be determined (e.g., a nil slice or a zero length
// slize). This function may also panic if it finds a type that cannot be
// expressed in TOML (such as nil elements, heterogeneous arrays or directly
// nested arrays of tables).
func tomlArrayType(rv reflect.Value) tomlType {
if isNil(rv) || !rv.IsValid() || rv.Len() == 0 {
return nil
}
firstType := tomlTypeOfGo(rv.Index(0))
if firstType == nil {
encPanic(errArrayNilElement)
}
rvlen := rv.Len()
for i := 1; i < rvlen; i++ {
elem := rv.Index(i)
switch elemType := tomlTypeOfGo(elem); {
case elemType == nil:
encPanic(errArrayNilElement)
case !typeEqual(firstType, elemType):
encPanic(errArrayMixedElementTypes)
}
}
// If we have a nested array, then we must make sure that the nested
// array contains ONLY primitives.
// This checks arbitrarily nested arrays.
if typeEqual(firstType, tomlArray) || typeEqual(firstType, tomlArrayHash) {
nest := tomlArrayType(eindirect(rv.Index(0)))
if typeEqual(nest, tomlHash) || typeEqual(nest, tomlArrayHash) {
encPanic(errArrayNoTable)
}
}
return firstType
}
// evalCall executes a function or method call. If it's a method, fun already has the receiver bound, so
// it looks just like a function call. The arg list, if non-nil, includes (in the manner of the shell), arg[0]
// as the function itself.
func (s *state) evalCall(dot, fun reflect.Value, node parse.Node, name string, args []parse.Node, final reflect.Value) reflect.Value {
if args != nil {
args = args[1:] // Zeroth arg is function name/node; not passed to function.
}
typ := fun.Type()
numIn := len(args)
if final.IsValid() {
numIn++
}
numFixed := len(args)
if typ.IsVariadic() {
numFixed = typ.NumIn() - 1 // last arg is the variadic one.
if numIn < numFixed {
s.errorf("wrong number of args for %s: want at least %d got %d", name, typ.NumIn()-1, len(args))
}
} else if numIn < typ.NumIn()-1 || !typ.IsVariadic() && numIn != typ.NumIn() {
s.errorf("wrong number of args for %s: want %d got %d", name, typ.NumIn(), len(args))
}
if !goodFunc(typ) {
// TODO: This could still be a confusing error; maybe goodFunc should provide info.
s.errorf("can't call method/function %q with %d results", name, typ.NumOut())
}
// Build the arg list.
argv := make([]reflect.Value, numIn)
// Args must be evaluated. Fixed args first.
i := 0
for ; i < numFixed && i < len(args); i++ {
argv[i] = s.evalArg(dot, typ.In(i), args[i])
}
// Now the ... args.
if typ.IsVariadic() {
argType := typ.In(typ.NumIn() - 1).Elem() // Argument is a slice.
for ; i < len(args); i++ {
argv[i] = s.evalArg(dot, argType, args[i])
}
}
// Add final value if necessary.
if final.IsValid() {
t := typ.In(typ.NumIn() - 1)
if typ.IsVariadic() {
if numIn-1 < numFixed {
// The added final argument corresponds to a fixed parameter of the function.
// Validate against the type of the actual parameter.
t = typ.In(numIn - 1)
} else {
// The added final argument corresponds to the variadic part.
// Validate against the type of the elements of the variadic slice.
t = t.Elem()
}
}
argv[i] = s.validateType(final, t)
}
result := fun.Call(argv)
// If we have an error that is not nil, stop execution and return that error to the caller.
if len(result) == 2 && !result[1].IsNil() {
s.at(node)
s.errorf("error calling %s: %s", name, result[1].Interface().(error))
}
return result[0]
}
// evalField evaluates an expression like (.Field) or (.Field arg1 arg2).
// The 'final' argument represents the return value from the preceding
// value of the pipeline, if any.
func (s *state) evalField(dot reflect.Value, fieldName string, node parse.Node, args []parse.Node, final, receiver reflect.Value) reflect.Value {
if !receiver.IsValid() {
return zero
}
typ := receiver.Type()
receiver, _ = indirect(receiver)
// Unless it's an interface, need to get to a value of type *T to guarantee
// we see all methods of T and *T.
ptr := receiver
if ptr.Kind() != reflect.Interface && ptr.CanAddr() {
ptr = ptr.Addr()
}
if method := ptr.MethodByName(fieldName); method.IsValid() {
return s.evalCall(dot, method, node, fieldName, args, final)
}
hasArgs := len(args) > 1 || final.IsValid()
// It's not a method; must be a field of a struct or an element of a map. The receiver must not be nil.
receiver, isNil := indirect(receiver)
if isNil {
s.errorf("nil pointer evaluating %s.%s", typ, fieldName)
}
switch receiver.Kind() {
case reflect.Struct:
tField, ok := receiver.Type().FieldByName(fieldName)
if ok {
field := receiver.FieldByIndex(tField.Index)
if tField.PkgPath != "" { // field is unexported
s.errorf("%s is an unexported field of struct type %s", fieldName, typ)
}
// If it's a function, we must call it.
if hasArgs {
s.errorf("%s has arguments but cannot be invoked as function", fieldName)
}
return field
}
s.errorf("%s is not a field of struct type %s", fieldName, typ)
case reflect.Map:
// If it's a map, attempt to use the field name as a key.
nameVal := reflect.ValueOf(fieldName)
if nameVal.Type().AssignableTo(receiver.Type().Key()) {
if hasArgs {
s.errorf("%s is not a method but has arguments", fieldName)
}
result := receiver.MapIndex(nameVal)
if !result.IsValid() {
switch s.tmpl.option.missingKey {
case mapInvalid:
// Just use the invalid value.
case mapZeroValue:
result = reflect.Zero(receiver.Type().Elem())
case mapError:
s.errorf("map has no entry for key %q", fieldName)
}
}
return result
}
}
s.errorf("can't evaluate field %s in type %s", fieldName, typ)
panic("not reached")
}
func valueEncoder(v reflect.Value) encoderFunc {
if !v.IsValid() {
return invalidValueEncoder
}
t := v.Type()
return typeEncoder(t, v)
}
// validateType guarantees that the value is valid and assignable to the type.
func (s *state) validateType(value reflect.Value, typ reflect.Type) reflect.Value {
if !value.IsValid() {
if typ == nil || canBeNil(typ) {
// An untyped nil interface{}. Accept as a proper nil value.
return reflect.Zero(typ)
}
s.errorf("invalid value; expected %s", typ)
}
if typ != nil && !value.Type().AssignableTo(typ) {
if value.Kind() == reflect.Interface && !value.IsNil() {
value = value.Elem()
if value.Type().AssignableTo(typ) {
return value
}
// fallthrough
}
// Does one dereference or indirection work? We could do more, as we
// do with method receivers, but that gets messy and method receivers
// are much more constrained, so it makes more sense there than here.
// Besides, one is almost always all you need.
switch {
case value.Kind() == reflect.Ptr && value.Type().Elem().AssignableTo(typ):
value = value.Elem()
if !value.IsValid() {
s.errorf("dereference of nil pointer of type %s", typ)
}
case reflect.PtrTo(value.Type()).AssignableTo(typ) && value.CanAddr():
value = value.Addr()
default:
s.errorf("wrong type for value; expected %s; got %s", typ, value.Type())
}
}
return value
}
// Add adds a new process with a given name to the network.
// It returns true on success or panics and returns false on error.
func (n *Graph) Add(c interface{}, name string) bool {
// Check if passed interface is a valid pointer to struct
v := reflect.ValueOf(c)
if v.Kind() != reflect.Ptr || v.IsNil() {
panic("flow.Graph.Add() argument is not a valid pointer")
return false
}
v = v.Elem()
if v.Kind() != reflect.Struct {
panic("flow.Graph.Add() argument is not a valid pointer to struct")
return false
}
// Set the link to self in the proccess so that it could use it
var vNet reflect.Value
vCom := v.FieldByName("Component")
if vCom.IsValid() && vCom.Type().Name() == "Component" {
vNet = vCom.FieldByName("Net")
} else {
vGraph := v.FieldByName("Graph")
if vGraph.IsValid() && vGraph.Type().Name() == "Graph" {
vNet = vGraph.FieldByName("Net")
}
}
if vNet.IsValid() && vNet.CanSet() {
vNet.Set(reflect.ValueOf(n))
}
// Add to the map of processes
n.procs[name] = c
return true
}
func (scope *Scope) getPrimaryKey() string {
var indirectValue reflect.Value
indirectValue = reflect.Indirect(reflect.ValueOf(scope.Value))
if indirectValue.Kind() == reflect.Slice {
indirectValue = reflect.New(indirectValue.Type().Elem()).Elem()
}
if !indirectValue.IsValid() {
return "id"
}
scopeTyp := indirectValue.Type()
for i := 0; i < scopeTyp.NumField(); i++ {
fieldStruct := scopeTyp.Field(i)
if !ast.IsExported(fieldStruct.Name) {
continue
}
// if primaryKey tag found, return column name
if fieldStruct.Tag.Get("primaryKey") != "" {
return ToSnake(fieldStruct.Name)
}
}
//If primaryKey tag not found, fallback to id
return "id"
}
func (n *Graph) getPort(procName, portName string,
extractFromPM func(portMapper, string) reflect.Value) (reflect.Value, error) {
proc, found := n.procs[procName]
var port reflect.Value
if !found {
return port, errors.New("name '" + procName + "' not found")
}
v := reflect.ValueOf(proc).Elem()
if !v.CanSet() {
return port, errors.New(procName + " is not settable")
}
var net reflect.Value
if v.Type().Name() == "Graph" {
net = v
} else {
net = v.FieldByName("Graph")
}
if net.IsValid() {
// Port is a net
if pm, isPm := net.Addr().Interface().(portMapper); isPm {
port = extractFromPM(pm, portName)
}
} else {
// Port is a proc
port = v.FieldByName(portName)
}
return port, nil
}
func (scan *Scan) ScanToStruct(rows *sql.Rows, record reflect.Value) error {
columns, err := rows.Columns()
if err != nil {
return err
}
values := make([]interface{}, len(columns))
for i, column := range columns {
var field reflect.Value
fieldName := scan.SQLColumnDict[column]
if scan.ToPointers {
field = record.Elem().FieldByName(fieldName)
} else {
field = record.FieldByName(fieldName)
}
if field.IsValid() {
values[i] = field.Addr().Interface()
} else {
values[i] = &values[i]
}
}
return rows.Scan(values...)
}
func valueHeader(v reflect.Value) (h *reflect.SliceHeader) {
if v.IsValid() {
size := int(v.Type().Size())
h = &reflect.SliceHeader{v.UnsafeAddr(), size, size}
}
return
}
func unflattenValue(v reflect.Value, t reflect.Type) reflect.Value {
// When t is an Interface, we can't do much, since we don't know the
// original (unflattened) type of the value placed in v, so we just nop it.
if t.Kind() == reflect.Interface {
return v
}
// v can be invalid, if it holds the nil value for pointer type
if !v.IsValid() {
return v
}
// Make sure v is indeed flat
if v.Kind() == reflect.Ptr {
panic("unflattening non-flat value")
}
// Add a *, one at a time
for t.Kind() == reflect.Ptr {
if v.CanAddr() {
v = v.Addr()
} else {
pw := reflect.New(v.Type())
pw.Elem().Set(v)
v = pw
}
t = t.Elem()
}
return v
}
func assertValid(vObj reflect.Value) error {
if !vObj.IsValid() {
return nil
}
if obj, ok := vObj.Interface().(interface {
AssertValid() error
}); ok && !(vObj.Kind() == reflect.Ptr && vObj.IsNil()) {
if err := obj.AssertValid(); err != nil {
return err
}
}
switch vObj.Kind() {
case reflect.Ptr:
return assertValid(vObj.Elem())
case reflect.Struct:
return assertStructValid(vObj)
case reflect.Slice:
for i := 0; i < vObj.Len(); i++ {
if err := assertValid(vObj.Index(i)); err != nil {
return err
}
}
}
return nil
}
func (q *queryParser) parseValue(v url.Values, value reflect.Value, prefix string, tag reflect.StructTag) error {
value = elemOf(value)
// no need to handle zero values
if !value.IsValid() {
return nil
}
t := tag.Get("type")
if t == "" {
switch value.Kind() {
case reflect.Struct:
t = "structure"
case reflect.Slice:
t = "list"
case reflect.Map:
t = "map"
}
}
switch t {
case "structure":
return q.parseStruct(v, value, prefix)
case "list":
return q.parseList(v, value, prefix, tag)
case "map":
return q.parseMap(v, value, prefix, tag)
default:
return q.parseScalar(v, value, prefix, tag)
}
}
// value decodes a JSON value from d.data[d.off:] into the value.
// it updates d.off to point past the decoded value.
func (d *decodeState) value(v reflect.Value) {
if !v.IsValid() {
_, rest, err := nextValue(d.data[d.off:], &d.nextscan)
if err != nil {
d.error(err)
}
d.off = len(d.data) - len(rest)
// d.scan thinks we're still at the beginning of the item.
// Feed in an empty string - the shortest, simplest value -
// so that it knows we got to the end of the value.
if d.scan.redo {
// rewind.
d.scan.redo = false
d.scan.step = stateBeginValue
}
d.scan.step(&d.scan, '"')
d.scan.step(&d.scan, '"')
return
}
switch op := d.scanWhile(scanSkipSpace); op {
default:
d.error(errPhase)
case scanBeginArray:
d.array(v)
case scanBeginObject:
d.object(v)
case scanBeginLiteral:
d.literal(v)
}
}
func convertType(v reflect.Value) (*string, error) {
v = reflect.Indirect(v)
if !v.IsValid() {
return nil, nil
}
var str string
switch value := v.Interface().(type) {
case string:
str = value
case []byte:
str = base64.StdEncoding.EncodeToString(value)
case bool:
str = strconv.FormatBool(value)
case int64:
str = strconv.FormatInt(value, 10)
case float64:
str = strconv.FormatFloat(value, 'f', -1, 64)
case time.Time:
str = value.UTC().Format(RFC822)
default:
err := fmt.Errorf("Unsupported value for param %v (%s)", v.Interface(), v.Type())
return nil, err
}
return &str, nil
}
// isTrue reports whether the value is 'true', in the sense of not the zero of its type,
// and whether the value has a meaningful truth value.
func isTrue(val reflect.Value) (truth, ok bool) {
if !val.IsValid() {
// Something like var x interface{}, never set. It's a form of nil.
return false, true
}
switch val.Kind() {
case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
truth = val.Len() > 0
case reflect.Bool:
truth = val.Bool()
case reflect.Complex64, reflect.Complex128:
truth = val.Complex() != 0
case reflect.Chan, reflect.Func, reflect.Ptr, reflect.Interface:
truth = !val.IsNil()
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
truth = val.Int() != 0
case reflect.Float32, reflect.Float64:
truth = val.Float() != 0
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
truth = val.Uint() != 0
case reflect.Struct:
truth = true // Struct values are always true.
default:
return
}
return truth, true
}
func ReturnWhenSet(a, k interface{}) interface{} {
av, isNil := indirect(reflect.ValueOf(a))
if isNil {
return ""
}
var avv reflect.Value
switch av.Kind() {
case reflect.Array, reflect.Slice:
index, ok := k.(int)
if ok && av.Len() > index {
avv = av.Index(index)
}
case reflect.Map:
kv := reflect.ValueOf(k)
if kv.Type().AssignableTo(av.Type().Key()) {
avv = av.MapIndex(kv)
}
}
if avv.IsValid() {
switch avv.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return avv.Int()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
return avv.Uint()
case reflect.Float32, reflect.Float64:
return avv.Float()
case reflect.String:
return avv.String()
}
}
return ""
}
// validateType guarantees that the value is valid and assignable to the type.
func (s *state) validateType(value reflect.Value, typ reflect.Type) reflect.Value {
if !value.IsValid() {
switch typ.Kind() {
case reflect.Interface, reflect.Ptr, reflect.Chan, reflect.Map, reflect.Slice, reflect.Func:
// An untyped nil interface{}. Accept as a proper nil value.
// TODO: Can we delete the other types in this list? Should we?
value = reflect.Zero(typ)
default:
s.errorf("invalid value; expected %s", typ)
}
}
if !value.Type().AssignableTo(typ) {
// Does one dereference or indirection work? We could do more, as we
// do with method receivers, but that gets messy and method receivers
// are much more constrained, so it makes more sense there than here.
// Besides, one is almost always all you need.
switch {
case value.Kind() == reflect.Ptr && value.Type().Elem().AssignableTo(typ):
value = value.Elem()
case reflect.PtrTo(value.Type()).AssignableTo(typ) && value.CanAddr():
value = value.Addr()
default:
s.errorf("wrong type for value; expected %s; got %s", typ, value.Type())
}
}
return value
}