Official Go implementation of the Ethereum protocol
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go-ethereum/vendor/github.com/robertkrimen/otto/evaluate.go

319 lines
8.1 KiB

package otto
import (
"fmt"
"math"
"strings"
"github.com/robertkrimen/otto/token"
)
func (self *_runtime) evaluateMultiply(left float64, right float64) Value {
// TODO 11.5.1
return Value{}
}
func (self *_runtime) evaluateDivide(left float64, right float64) Value {
if math.IsNaN(left) || math.IsNaN(right) {
return NaNValue()
}
if math.IsInf(left, 0) && math.IsInf(right, 0) {
return NaNValue()
}
if left == 0 && right == 0 {
return NaNValue()
}
if math.IsInf(left, 0) {
if math.Signbit(left) == math.Signbit(right) {
return positiveInfinityValue()
} else {
return negativeInfinityValue()
}
}
if math.IsInf(right, 0) {
if math.Signbit(left) == math.Signbit(right) {
return positiveZeroValue()
} else {
return negativeZeroValue()
}
}
if right == 0 {
if math.Signbit(left) == math.Signbit(right) {
return positiveInfinityValue()
} else {
return negativeInfinityValue()
}
}
return toValue_float64(left / right)
}
func (self *_runtime) evaluateModulo(left float64, right float64) Value {
// TODO 11.5.3
return Value{}
}
func (self *_runtime) calculateBinaryExpression(operator token.Token, left Value, right Value) Value {
leftValue := left.resolve()
switch operator {
// Additive
case token.PLUS:
leftValue = toPrimitive(leftValue)
rightValue := right.resolve()
rightValue = toPrimitive(rightValue)
if leftValue.IsString() || rightValue.IsString() {
return toValue_string(strings.Join([]string{leftValue.string(), rightValue.string()}, ""))
} else {
return toValue_float64(leftValue.float64() + rightValue.float64())
}
case token.MINUS:
rightValue := right.resolve()
return toValue_float64(leftValue.float64() - rightValue.float64())
// Multiplicative
case token.MULTIPLY:
rightValue := right.resolve()
return toValue_float64(leftValue.float64() * rightValue.float64())
case token.SLASH:
rightValue := right.resolve()
return self.evaluateDivide(leftValue.float64(), rightValue.float64())
case token.REMAINDER:
rightValue := right.resolve()
return toValue_float64(math.Mod(leftValue.float64(), rightValue.float64()))
// Logical
case token.LOGICAL_AND:
left := leftValue.bool()
if !left {
return falseValue
}
return toValue_bool(right.resolve().bool())
case token.LOGICAL_OR:
left := leftValue.bool()
if left {
return trueValue
}
return toValue_bool(right.resolve().bool())
// Bitwise
case token.AND:
rightValue := right.resolve()
return toValue_int32(toInt32(leftValue) & toInt32(rightValue))
case token.OR:
rightValue := right.resolve()
return toValue_int32(toInt32(leftValue) | toInt32(rightValue))
case token.EXCLUSIVE_OR:
rightValue := right.resolve()
return toValue_int32(toInt32(leftValue) ^ toInt32(rightValue))
// Shift
// (Masking of 0x1f is to restrict the shift to a maximum of 31 places)
case token.SHIFT_LEFT:
rightValue := right.resolve()
return toValue_int32(toInt32(leftValue) << (toUint32(rightValue) & 0x1f))
case token.SHIFT_RIGHT:
rightValue := right.resolve()
return toValue_int32(toInt32(leftValue) >> (toUint32(rightValue) & 0x1f))
case token.UNSIGNED_SHIFT_RIGHT:
rightValue := right.resolve()
// Shifting an unsigned integer is a logical shift
return toValue_uint32(toUint32(leftValue) >> (toUint32(rightValue) & 0x1f))
case token.INSTANCEOF:
rightValue := right.resolve()
if !rightValue.IsObject() {
panic(self.panicTypeError("Expecting a function in instanceof check, but got: %v", rightValue))
}
return toValue_bool(rightValue._object().hasInstance(leftValue))
case token.IN:
rightValue := right.resolve()
if !rightValue.IsObject() {
panic(self.panicTypeError())
}
return toValue_bool(rightValue._object().hasProperty(leftValue.string()))
}
panic(hereBeDragons(operator))
}
func valueKindDispatchKey(left _valueKind, right _valueKind) int {
return (int(left) << 2) + int(right)
}
var equalDispatch map[int](func(Value, Value) bool) = makeEqualDispatch()
func makeEqualDispatch() map[int](func(Value, Value) bool) {
key := valueKindDispatchKey
return map[int](func(Value, Value) bool){
key(valueNumber, valueObject): func(x Value, y Value) bool { return x.float64() == y.float64() },
key(valueString, valueObject): func(x Value, y Value) bool { return x.float64() == y.float64() },
key(valueObject, valueNumber): func(x Value, y Value) bool { return x.float64() == y.float64() },
key(valueObject, valueString): func(x Value, y Value) bool { return x.float64() == y.float64() },
}
}
type _lessThanResult int
const (
lessThanFalse _lessThanResult = iota
lessThanTrue
lessThanUndefined
)
func calculateLessThan(left Value, right Value, leftFirst bool) _lessThanResult {
x := Value{}
y := x
if leftFirst {
x = toNumberPrimitive(left)
y = toNumberPrimitive(right)
} else {
y = toNumberPrimitive(right)
x = toNumberPrimitive(left)
}
result := false
if x.kind != valueString || y.kind != valueString {
x, y := x.float64(), y.float64()
if math.IsNaN(x) || math.IsNaN(y) {
return lessThanUndefined
}
result = x < y
} else {
x, y := x.string(), y.string()
result = x < y
}
if result {
return lessThanTrue
}
return lessThanFalse
}
// FIXME Probably a map is not the most efficient way to do this
var lessThanTable [4](map[_lessThanResult]bool) = [4](map[_lessThanResult]bool){
// <
map[_lessThanResult]bool{
lessThanFalse: false,
lessThanTrue: true,
lessThanUndefined: false,
},
// >
map[_lessThanResult]bool{
lessThanFalse: false,
lessThanTrue: true,
lessThanUndefined: false,
},
// <=
map[_lessThanResult]bool{
lessThanFalse: true,
lessThanTrue: false,
lessThanUndefined: false,
},
// >=
map[_lessThanResult]bool{
lessThanFalse: true,
lessThanTrue: false,
lessThanUndefined: false,
},
}
func (self *_runtime) calculateComparison(comparator token.Token, left Value, right Value) bool {
// FIXME Use strictEqualityComparison?
// TODO This might be redundant now (with regards to evaluateComparison)
x := left.resolve()
y := right.resolve()
kindEqualKind := false
result := true
negate := false
switch comparator {
case token.LESS:
result = lessThanTable[0][calculateLessThan(x, y, true)]
case token.GREATER:
result = lessThanTable[1][calculateLessThan(y, x, false)]
case token.LESS_OR_EQUAL:
result = lessThanTable[2][calculateLessThan(y, x, false)]
case token.GREATER_OR_EQUAL:
result = lessThanTable[3][calculateLessThan(x, y, true)]
case token.STRICT_NOT_EQUAL:
negate = true
fallthrough
case token.STRICT_EQUAL:
if x.kind != y.kind {
result = false
} else {
kindEqualKind = true
}
case token.NOT_EQUAL:
negate = true
fallthrough
case token.EQUAL:
if x.kind == y.kind {
kindEqualKind = true
} else if x.kind <= valueNull && y.kind <= valueNull {
result = true
} else if x.kind <= valueNull || y.kind <= valueNull {
result = false
} else if x.kind <= valueString && y.kind <= valueString {
result = x.float64() == y.float64()
} else if x.kind == valueBoolean {
result = self.calculateComparison(token.EQUAL, toValue_float64(x.float64()), y)
} else if y.kind == valueBoolean {
result = self.calculateComparison(token.EQUAL, x, toValue_float64(y.float64()))
} else if x.kind == valueObject {
result = self.calculateComparison(token.EQUAL, toPrimitive(x), y)
} else if y.kind == valueObject {
result = self.calculateComparison(token.EQUAL, x, toPrimitive(y))
} else {
panic(hereBeDragons("Unable to test for equality: %v ==? %v", x, y))
}
default:
panic(fmt.Errorf("Unknown comparator %s", comparator.String()))
}
if kindEqualKind {
switch x.kind {
case valueUndefined, valueNull:
result = true
case valueNumber:
x := x.float64()
y := y.float64()
if math.IsNaN(x) || math.IsNaN(y) {
result = false
} else {
result = x == y
}
case valueString:
result = x.string() == y.string()
case valueBoolean:
result = x.bool() == y.bool()
case valueObject:
result = x._object() == y._object()
default:
goto ERROR
}
}
if negate {
result = !result
}
return result
ERROR:
panic(hereBeDragons("%v (%v) %s %v (%v)", x, x.kind, comparator, y, y.kind))
}