diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/robertkrimen/otto/evaluate.go')
-rw-r--r-- | Godeps/_workspace/src/github.com/robertkrimen/otto/evaluate.go | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/robertkrimen/otto/evaluate.go b/Godeps/_workspace/src/github.com/robertkrimen/otto/evaluate.go new file mode 100644 index 000000000..093054cc3 --- /dev/null +++ b/Godeps/_workspace/src/github.com/robertkrimen/otto/evaluate.go @@ -0,0 +1,318 @@ +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)) +} |