plugeth/Godeps/_workspace/src/github.com/obscuren/otto/value.go

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2015-02-16 13:28:33 +00:00
package otto
import (
"fmt"
"math"
"reflect"
"strconv"
"unicode/utf16"
)
type _valueType int
const (
valueEmpty _valueType = iota
valueNull
valueUndefined
valueNumber
valueString
valueBoolean
valueObject
valueResult
valueReference
)
// Value is the representation of a JavaScript value.
type Value struct {
_valueType
value interface{}
}
// ToValue will convert an interface{} value to a value digestible by otto/JavaScript
// This function will not work for advanced types (struct, map, slice/array, etc.) and
// you probably should not use it.
//
// ToValue may be deprecated and removed in the near future.
//
// Try Otto.ToValue for a replacement.
func ToValue(value interface{}) (Value, error) {
result := UndefinedValue()
err := catchPanic(func() {
result = toValue(value)
})
return result, err
}
// Empty
func emptyValue() Value {
return Value{_valueType: valueEmpty}
}
func (value Value) isEmpty() bool {
return value._valueType == valueEmpty
}
// Undefined
// UndefinedValue will return a Value representing undefined.
func UndefinedValue() Value {
return Value{_valueType: valueUndefined}
}
// IsDefined will return false if the value is undefined, and true otherwise.
func (value Value) IsDefined() bool {
return value._valueType != valueUndefined
}
// IsUndefined will return true if the value is undefined, and false otherwise.
func (value Value) IsUndefined() bool {
return value._valueType == valueUndefined
}
// NullValue will return a Value representing null.
func NullValue() Value {
return Value{_valueType: valueNull}
}
// IsNull will return true if the value is null, and false otherwise.
func (value Value) IsNull() bool {
return value._valueType == valueNull
}
// ---
func (value Value) isCallable() bool {
switch value := value.value.(type) {
case *_object:
return value.functionValue().call != nil
}
return false
}
func (value Value) isResult() bool {
return value._valueType == valueResult
}
func (value Value) isReference() bool {
return value._valueType == valueReference
}
// Call the value as a function with the given this value and argument list and
// return the result of invocation. It is essentially equivalent to:
//
// value.apply(thisValue, argumentList)
//
// An undefined value and an error will result if:
//
// 1. There is an error during conversion of the argument list
// 2. The value is not actually a function
// 3. An (uncaught) exception is thrown
//
func (value Value) Call(this Value, argumentList ...interface{}) (Value, error) {
result := UndefinedValue()
err := catchPanic(func() {
result = value.call(this, argumentList...)
})
return result, err
}
func (value Value) call(this Value, argumentList ...interface{}) Value {
switch function := value.value.(type) {
case *_object:
return function.Call(this, argumentList...)
}
panic(newTypeError())
}
func (value Value) constructSafe(this Value, argumentList ...interface{}) (Value, error) {
result := UndefinedValue()
err := catchPanic(func() {
result = value.construct(this, argumentList...)
})
return result, err
}
func (value Value) construct(this Value, argumentList ...interface{}) Value {
switch function := value.value.(type) {
case *_object:
return function.Construct(this, argumentList...)
}
panic(newTypeError())
}
// IsPrimitive will return true if value is a primitive (any kind of primitive).
func (value Value) IsPrimitive() bool {
return !value.IsObject()
}
// IsBoolean will return true if value is a boolean (primitive).
func (value Value) IsBoolean() bool {
return value._valueType == valueBoolean
}
// IsNumber will return true if value is a number (primitive).
func (value Value) IsNumber() bool {
return value._valueType == valueNumber
}
// IsNaN will return true if value is NaN (or would convert to NaN).
func (value Value) IsNaN() bool {
switch value := value.value.(type) {
case float64:
return math.IsNaN(value)
case float32:
return math.IsNaN(float64(value))
case int, int8, int32, int64:
return false
case uint, uint8, uint32, uint64:
return false
}
return math.IsNaN(toFloat(value))
}
// IsString will return true if value is a string (primitive).
func (value Value) IsString() bool {
return value._valueType == valueString
}
// IsObject will return true if value is an object.
func (value Value) IsObject() bool {
return value._valueType == valueObject
}
// IsFunction will return true if value is a function.
func (value Value) IsFunction() bool {
if value._valueType != valueObject {
return false
}
return value.value.(*_object).class == "Function"
}
// Class will return the class string of the value or the empty string if value is not an object.
//
// The return value will (generally) be one of:
//
// Object
// Function
// Array
// String
// Number
// Boolean
// Date
// RegExp
//
func (value Value) Class() string {
if value._valueType != valueObject {
return ""
}
return value.value.(*_object).class
}
func (value Value) isArray() bool {
if value._valueType != valueObject {
return false
}
return isArray(value.value.(*_object))
}
func (value Value) isStringObject() bool {
if value._valueType != valueObject {
return false
}
return value.value.(*_object).class == "String"
}
func (value Value) isBooleanObject() bool {
if value._valueType != valueObject {
return false
}
return value.value.(*_object).class == "Boolean"
}
func (value Value) isNumberObject() bool {
if value._valueType != valueObject {
return false
}
return value.value.(*_object).class == "Number"
}
func (value Value) isDate() bool {
if value._valueType != valueObject {
return false
}
return value.value.(*_object).class == "Date"
}
func (value Value) isRegExp() bool {
if value._valueType != valueObject {
return false
}
return value.value.(*_object).class == "RegExp"
}
func (value Value) isError() bool {
if value._valueType != valueObject {
return false
}
return value.value.(*_object).class == "Error"
}
// ---
func toValue_reflectValuePanic(value interface{}, kind reflect.Kind) {
switch kind {
case reflect.Struct:
panic(newTypeError("Invalid value (struct): Missing runtime: %v (%T)", value, value))
case reflect.Map:
panic(newTypeError("Invalid value (map): Missing runtime: %v (%T)", value, value))
case reflect.Slice:
panic(newTypeError("Invalid value (slice): Missing runtime: %v (%T)", value, value))
}
}
func toValue(value interface{}) Value {
switch value := value.(type) {
case Value:
return value
case bool:
return Value{valueBoolean, value}
case int:
return Value{valueNumber, value}
case int8:
return Value{valueNumber, value}
case int16:
return Value{valueNumber, value}
case int32:
return Value{valueNumber, value}
case int64:
return Value{valueNumber, value}
case uint:
return Value{valueNumber, value}
case uint8:
return Value{valueNumber, value}
case uint16:
return Value{valueNumber, value}
case uint32:
return Value{valueNumber, value}
case uint64:
return Value{valueNumber, value}
case float32:
return Value{valueNumber, float64(value)}
case float64:
return Value{valueNumber, value}
case []uint16:
return Value{valueString, value}
case string:
return Value{valueString, value}
// A rune is actually an int32, which is handled above
case *_object:
return Value{valueObject, value}
case *Object:
return Value{valueObject, value.object}
case Object:
return Value{valueObject, value.object}
case _reference: // reference is an interface (already a pointer)
return Value{valueReference, value}
case _result:
return Value{valueResult, value}
case nil:
// TODO Ugh.
return UndefinedValue()
case reflect.Value:
for value.Kind() == reflect.Ptr {
// We were given a pointer, so we'll drill down until we get a non-pointer
//
// These semantics might change if we want to start supporting pointers to values transparently
// (It would be best not to depend on this behavior)
// FIXME: UNDEFINED
if value.IsNil() {
return UndefinedValue()
}
value = value.Elem()
}
switch value.Kind() {
case reflect.Bool:
return Value{valueBoolean, bool(value.Bool())}
case reflect.Int:
return Value{valueNumber, int(value.Int())}
case reflect.Int8:
return Value{valueNumber, int8(value.Int())}
case reflect.Int16:
return Value{valueNumber, int16(value.Int())}
case reflect.Int32:
return Value{valueNumber, int32(value.Int())}
case reflect.Int64:
return Value{valueNumber, int64(value.Int())}
case reflect.Uint:
return Value{valueNumber, uint(value.Uint())}
case reflect.Uint8:
return Value{valueNumber, uint8(value.Uint())}
case reflect.Uint16:
return Value{valueNumber, uint16(value.Uint())}
case reflect.Uint32:
return Value{valueNumber, uint32(value.Uint())}
case reflect.Uint64:
return Value{valueNumber, uint64(value.Uint())}
case reflect.Float32:
return Value{valueNumber, float32(value.Float())}
case reflect.Float64:
return Value{valueNumber, float64(value.Float())}
case reflect.String:
return Value{valueString, string(value.String())}
default:
toValue_reflectValuePanic(value.Interface(), value.Kind())
}
default:
return toValue(reflect.ValueOf(value))
}
panic(newTypeError("Invalid value: Unsupported: %v (%T)", value, value))
}
// String will return the value as a string.
//
// This method will make return the empty string if there is an error.
func (value Value) String() string {
result := ""
catchPanic(func() {
result = value.toString()
})
return result
}
func (value Value) toBoolean() bool {
return toBoolean(value)
}
func (value Value) isTrue() bool {
return toBoolean(value)
}
// ToBoolean will convert the value to a boolean (bool).
//
// ToValue(0).ToBoolean() => false
// ToValue("").ToBoolean() => false
// ToValue(true).ToBoolean() => true
// ToValue(1).ToBoolean() => true
// ToValue("Nothing happens").ToBoolean() => true
//
// If there is an error during the conversion process (like an uncaught exception), then the result will be false and an error.
func (value Value) ToBoolean() (bool, error) {
result := false
err := catchPanic(func() {
result = toBoolean(value)
})
return result, err
}
func (value Value) toNumber() Value {
return toNumber(value)
}
func (value Value) toFloat() float64 {
return toFloat(value)
}
// ToFloat will convert the value to a number (float64).
//
// ToValue(0).ToFloat() => 0.
// ToValue(1.1).ToFloat() => 1.1
// ToValue("11").ToFloat() => 11.
//
// If there is an error during the conversion process (like an uncaught exception), then the result will be 0 and an error.
func (value Value) ToFloat() (float64, error) {
result := float64(0)
err := catchPanic(func() {
result = toFloat(value)
})
return result, err
}
// ToInteger will convert the value to a number (int64).
//
// ToValue(0).ToInteger() => 0
// ToValue(1.1).ToInteger() => 1
// ToValue("11").ToInteger() => 11
//
// If there is an error during the conversion process (like an uncaught exception), then the result will be 0 and an error.
func (value Value) ToInteger() (int64, error) {
result := int64(0)
err := catchPanic(func() {
result = toInteger(value).value
})
return result, err
}
func (value Value) toString() string {
return toString(value)
}
// ToString will convert the value to a string (string).
//
// ToValue(0).ToString() => "0"
// ToValue(false).ToString() => "false"
// ToValue(1.1).ToString() => "1.1"
// ToValue("11").ToString() => "11"
// ToValue('Nothing happens.').ToString() => "Nothing happens."
//
// If there is an error during the conversion process (like an uncaught exception), then the result will be the empty string ("") and an error.
func (value Value) ToString() (string, error) {
result := ""
err := catchPanic(func() {
result = toString(value)
})
return result, err
}
func (value Value) _object() *_object {
switch value := value.value.(type) {
case *_object:
return value
}
return nil
}
// Object will return the object of the value, or nil if value is not an object.
//
// This method will not do any implicit conversion. For example, calling this method on a string primitive value will not return a String object.
func (value Value) Object() *Object {
switch object := value.value.(type) {
case *_object:
return _newObject(object, value)
}
return nil
}
func (value Value) reference() _reference {
switch value := value.value.(type) {
case _reference:
return value
}
return nil
}
var (
__NaN__ float64 = math.NaN()
__PositiveInfinity__ float64 = math.Inf(+1)
__NegativeInfinity__ float64 = math.Inf(-1)
__PositiveZero__ float64 = 0
__NegativeZero__ float64 = math.Float64frombits(0 | (1 << 63))
)
func positiveInfinity() float64 {
return __PositiveInfinity__
}
func negativeInfinity() float64 {
return __NegativeInfinity__
}
func positiveZero() float64 {
return __PositiveZero__
}
func negativeZero() float64 {
return __NegativeZero__
}
// NaNValue will return a value representing NaN.
//
// It is equivalent to:
//
// ToValue(math.NaN())
//
func NaNValue() Value {
return Value{valueNumber, __NaN__}
}
func positiveInfinityValue() Value {
return Value{valueNumber, __PositiveInfinity__}
}
func negativeInfinityValue() Value {
return Value{valueNumber, __NegativeInfinity__}
}
func positiveZeroValue() Value {
return Value{valueNumber, __PositiveZero__}
}
func negativeZeroValue() Value {
return Value{valueNumber, __NegativeZero__}
}
// TrueValue will return a value representing true.
//
// It is equivalent to:
//
// ToValue(true)
//
func TrueValue() Value {
return Value{valueBoolean, true}
}
// FalseValue will return a value representing false.
//
// It is equivalent to:
//
// ToValue(false)
//
func FalseValue() Value {
return Value{valueBoolean, false}
}
func sameValue(x Value, y Value) bool {
if x._valueType != y._valueType {
return false
}
result := false
switch x._valueType {
case valueUndefined, valueNull:
result = true
case valueNumber:
x := x.toFloat()
y := y.toFloat()
if math.IsNaN(x) && math.IsNaN(y) {
result = true
} else {
result = x == y
if result && x == 0 {
// Since +0 != -0
result = math.Signbit(x) == math.Signbit(y)
}
}
case valueString:
result = x.toString() == y.toString()
case valueBoolean:
result = x.toBoolean() == y.toBoolean()
case valueObject:
result = x._object() == y._object()
default:
panic(hereBeDragons())
}
return result
}
func strictEqualityComparison(x Value, y Value) bool {
if x._valueType != y._valueType {
return false
}
result := false
switch x._valueType {
case valueUndefined, valueNull:
result = true
case valueNumber:
x := x.toFloat()
y := y.toFloat()
if math.IsNaN(x) && math.IsNaN(y) {
result = false
} else {
result = x == y
}
case valueString:
result = x.toString() == y.toString()
case valueBoolean:
result = x.toBoolean() == y.toBoolean()
case valueObject:
result = x._object() == y._object()
default:
panic(hereBeDragons())
}
return result
}
// Export will attempt to convert the value to a Go representation
// and return it via an interface{} kind.
//
// WARNING: The interface function will be changing soon to:
//
// Export() interface{}
//
// If a reasonable conversion is not possible, then the original
// result is returned.
//
// undefined -> otto.Value (UndefinedValue())
// null -> interface{}(nil)
// boolean -> bool
// number -> A number type (int, float32, uint64, ...)
// string -> string
// Array -> []interface{}
// Object -> map[string]interface{}
//
func (self Value) Export() (interface{}, error) {
return self.export(), nil
}
func (self Value) export() interface{} {
switch self._valueType {
case valueUndefined:
return nil
case valueNull:
return nil
case valueNumber, valueBoolean:
return self.value
case valueString:
switch value := self.value.(type) {
case string:
return value
case []uint16:
return string(utf16.Decode(value))
}
case valueObject:
object := self._object()
switch value := object.value.(type) {
case *_goStructObject:
return value.value.Interface()
case *_goMapObject:
return value.value.Interface()
case *_goArrayObject:
return value.value.Interface()
case *_goSliceObject:
return value.value.Interface()
}
if object.class == "Array" {
result := make([]interface{}, 0)
lengthValue := object.get("length")
length := lengthValue.value.(uint32)
for index := uint32(0); index < length; index += 1 {
name := strconv.FormatInt(int64(index), 10)
if !object.hasProperty(name) {
continue
}
value := object.get(name)
result = append(result, value.export())
}
return result
} else {
result := make(map[string]interface{})
// TODO Should we export everything? Or just what is enumerable?
object.enumerate(false, func(name string) bool {
value := object.get(name)
if value.IsDefined() {
result[name] = value.export()
}
return true
})
return result
}
}
return self
}
func (self Value) evaluateBreakContinue(labels []string) _resultKind {
result := self.value.(_result)
if result.kind == resultBreak || result.kind == resultContinue {
for _, label := range labels {
if label == result.target {
return result.kind
}
}
}
return resultReturn
}
func (self Value) evaluateBreak(labels []string) _resultKind {
result := self.value.(_result)
if result.kind == resultBreak {
for _, label := range labels {
if label == result.target {
return result.kind
}
}
}
return resultReturn
}
func (self Value) exportNative() interface{} {
switch self._valueType {
case valueUndefined:
return self
case valueNull:
return nil
case valueNumber, valueBoolean:
return self.value
case valueString:
switch value := self.value.(type) {
case string:
return value
case []uint16:
return string(utf16.Decode(value))
}
case valueObject:
object := self._object()
switch value := object.value.(type) {
case *_goStructObject:
return value.value.Interface()
case *_goMapObject:
return value.value.Interface()
case *_goArrayObject:
return value.value.Interface()
case *_goSliceObject:
return value.value.Interface()
}
}
return self
}
func (value Value) toReflectValue(kind reflect.Kind) (reflect.Value, error) {
switch kind {
case reflect.Bool:
return reflect.ValueOf(value.toBoolean()), nil
case reflect.Int:
// We convert to float64 here because converting to int64 will not tell us
// if a value is outside the range of int64
tmp := toIntegerFloat(value)
if tmp < float_minInt || tmp > float_maxInt {
return reflect.Value{}, fmt.Errorf("RangeError: %d (%v) to int", tmp, value)
} else {
return reflect.ValueOf(int(tmp)), nil
}
case reflect.Int8:
tmp := toInteger(value).value
if tmp < int64_minInt8 || tmp > int64_maxInt8 {
return reflect.Value{}, fmt.Errorf("RangeError: %d (%v) to int8", tmp, value)
} else {
return reflect.ValueOf(int8(tmp)), nil
}
case reflect.Int16:
tmp := toInteger(value).value
if tmp < int64_minInt16 || tmp > int64_maxInt16 {
return reflect.Value{}, fmt.Errorf("RangeError: %d (%v) to int16", tmp, value)
} else {
return reflect.ValueOf(int16(tmp)), nil
}
case reflect.Int32:
tmp := toInteger(value).value
if tmp < int64_minInt32 || tmp > int64_maxInt32 {
return reflect.Value{}, fmt.Errorf("RangeError: %d (%v) to int32", tmp, value)
} else {
return reflect.ValueOf(int32(tmp)), nil
}
case reflect.Int64:
// We convert to float64 here because converting to int64 will not tell us
// if a value is outside the range of int64
tmp := toIntegerFloat(value)
if tmp < float_minInt64 || tmp > float_maxInt64 {
return reflect.Value{}, fmt.Errorf("RangeError: %d (%v) to int", tmp, value)
} else {
return reflect.ValueOf(int64(tmp)), nil
}
case reflect.Uint:
// We convert to float64 here because converting to int64 will not tell us
// if a value is outside the range of uint
tmp := toIntegerFloat(value)
if tmp < 0 || tmp > float_maxUint {
return reflect.Value{}, fmt.Errorf("RangeError: %d (%v) to uint", tmp, value)
} else {
return reflect.ValueOf(uint(tmp)), nil
}
case reflect.Uint8:
tmp := toInteger(value).value
if tmp < 0 || tmp > int64_maxUint8 {
return reflect.Value{}, fmt.Errorf("RangeError: %d (%v) to uint8", tmp, value)
} else {
return reflect.ValueOf(uint8(tmp)), nil
}
case reflect.Uint16:
tmp := toInteger(value).value
if tmp < 0 || tmp > int64_maxUint16 {
return reflect.Value{}, fmt.Errorf("RangeError: %d (%v) to uint16", tmp, value)
} else {
return reflect.ValueOf(uint16(tmp)), nil
}
case reflect.Uint32:
tmp := toInteger(value).value
if tmp < 0 || tmp > int64_maxUint32 {
return reflect.Value{}, fmt.Errorf("RangeError: %d (%v) to uint32", tmp, value)
} else {
return reflect.ValueOf(uint32(tmp)), nil
}
case reflect.Uint64:
// We convert to float64 here because converting to int64 will not tell us
// if a value is outside the range of uint64
tmp := toIntegerFloat(value)
if tmp < 0 || tmp > float_maxUint64 {
return reflect.Value{}, fmt.Errorf("RangeError: %f (%v) to uint64", tmp, value)
} else {
return reflect.ValueOf(uint64(tmp)), nil
}
case reflect.Float32:
tmp := toFloat(value)
tmp1 := tmp
if 0 > tmp1 {
tmp1 = -tmp1
}
if tmp1 < math.SmallestNonzeroFloat32 || tmp1 > math.MaxFloat32 {
return reflect.Value{}, fmt.Errorf("RangeError: %f (%v) to float32", tmp, value)
} else {
return reflect.ValueOf(float32(tmp)), nil
}
case reflect.Float64:
value := toFloat(value)
return reflect.ValueOf(float64(value)), nil
case reflect.String:
return reflect.ValueOf(value.toString()), nil
case reflect.Interface:
return reflect.ValueOf(value.exportNative()), nil
}
dbgf("%/panic//%@: Invalid: (%v) to reflect.Kind: %v", value, kind)
panic("")
}
func stringToReflectValue(value string, kind reflect.Kind) (reflect.Value, error) {
switch kind {
case reflect.Bool:
value, err := strconv.ParseBool(value)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(value), nil
case reflect.Int:
value, err := strconv.ParseInt(value, 0, 0)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(int(value)), nil
case reflect.Int8:
value, err := strconv.ParseInt(value, 0, 8)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(int8(value)), nil
case reflect.Int16:
value, err := strconv.ParseInt(value, 0, 16)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(int16(value)), nil
case reflect.Int32:
value, err := strconv.ParseInt(value, 0, 32)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(int32(value)), nil
case reflect.Int64:
value, err := strconv.ParseInt(value, 0, 64)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(int64(value)), nil
case reflect.Uint:
value, err := strconv.ParseUint(value, 0, 0)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(uint(value)), nil
case reflect.Uint8:
value, err := strconv.ParseUint(value, 0, 8)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(uint8(value)), nil
case reflect.Uint16:
value, err := strconv.ParseUint(value, 0, 16)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(uint16(value)), nil
case reflect.Uint32:
value, err := strconv.ParseUint(value, 0, 32)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(uint32(value)), nil
case reflect.Uint64:
value, err := strconv.ParseUint(value, 0, 64)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(uint64(value)), nil
case reflect.Float32:
value, err := strconv.ParseFloat(value, 32)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(float32(value)), nil
case reflect.Float64:
value, err := strconv.ParseFloat(value, 64)
if err != nil {
return reflect.Value{}, err
}
return reflect.ValueOf(float64(value)), nil
case reflect.String:
return reflect.ValueOf(value), nil
}
dbgf("%/panic//%@: Invalid: \"%s\" to reflect.Kind: %v", value, kind)
panic("")
}