Golang BinaryOperationExpr.SetValue方法代码示例

func (e *Evaluator) handleComparisonOp(o *ast.BinaryOperationExpr) bool {
	a, b := types.Coerce(o.L.GetValue(), o.R.GetValue())
	if types.IsNil(a) || types.IsNil(b) {
		// for <=>, if a and b are both nil, return true.
		// if a or b is nil, return false.
		if o.Op == opcode.NullEQ {
			if types.IsNil(a) || types.IsNil(b) {
				o.SetValue(oneI64)
			} else {
				o.SetValue(zeroI64)
			}
		} else {
			o.SetValue(nil)
		}
		return true
	}

	n, err := types.Compare(a, b)
	if err != nil {
		e.err = errors.Trace(err)
		return false
	}

	r, err := getCompResult(o.Op, n)
	if err != nil {
		e.err = errors.Trace(err)
		return false
	}
	if r {
		o.SetValue(oneI64)
	} else {
		o.SetValue(zeroI64)
	}
	return true
}

func (e *Evaluator) handleOrOr(o *ast.BinaryOperationExpr) bool {
	leftVal := o.L.GetValue()
	righVal := o.R.GetValue()
	if !types.IsNil(leftVal) {
		x, err := types.ToBool(leftVal)
		if err != nil {
			e.err = errors.Trace(err)
			return false
		} else if x == 1 {
			// true || any other types is true.
			o.SetValue(x)
			return true
		}
	}
	if !types.IsNil(righVal) {
		y, err := types.ToBool(righVal)
		if err != nil {
			e.err = errors.Trace(err)
			return false
		} else if y == 1 {
			o.SetValue(y)
			return true
		}
	}
	if types.IsNil(leftVal) || types.IsNil(righVal) {
		o.SetValue(nil)
		return true
	}
	o.SetValue(int64(0))
	return true
}

func (e *Evaluator) binaryOperation(o *ast.BinaryOperationExpr) bool {
	// all operands must have same column.
	if e.err = hasSameColumnCount(o.L, o.R); e.err != nil {
		return false
	}

	// row constructor only supports comparison operation.
	switch o.Op {
	case opcode.LT, opcode.LE, opcode.GE, opcode.GT, opcode.EQ, opcode.NE, opcode.NullEQ:
	default:
		if !checkAllOneColumn(o.L) {
			e.err = errors.Errorf("Operand should contain 1 column(s)")
			return false
		}
	}

	leftVal, err := types.Convert(o.L.GetValue(), o.GetType())
	if err != nil {
		e.err = err
		return false
	}
	rightVal, err := types.Convert(o.R.GetValue(), o.GetType())
	if err != nil {
		e.err = err
		return false
	}
	if leftVal == nil || rightVal == nil {
		o.SetValue(nil)
		return true
	}

	switch o.Op {
	case opcode.AndAnd, opcode.OrOr, opcode.LogicXor:
		return e.handleLogicOperation(o)
	case opcode.LT, opcode.LE, opcode.GE, opcode.GT, opcode.EQ, opcode.NE, opcode.NullEQ:
		return e.handleComparisonOp(o)
	case opcode.RightShift, opcode.LeftShift, opcode.And, opcode.Or, opcode.Xor:
		// TODO: MySQL doesn't support and not, we should remove it later.
		return e.handleBitOp(o)
	case opcode.Plus, opcode.Minus, opcode.Mod, opcode.Div, opcode.Mul, opcode.IntDiv:
		return e.handleArithmeticOp(o)
	default:
		panic("should never happen")
	}
}

func (e *Evaluator) handleArithmeticOp(o *ast.BinaryOperationExpr) bool {
	a, err := coerceArithmetic(o.L.GetValue())
	if err != nil {
		e.err = err
		return false
	}

	b, err := coerceArithmetic(o.R.GetValue())
	if err != nil {
		e.err = err
		return false
	}
	a, b = types.Coerce(a, b)

	if a == nil || b == nil {
		// TODO: for <=>, if a and b are both nil, return true
		o.SetValue(nil)
		return true
	}

	// TODO: support logic division DIV
	var result interface{}
	switch o.Op {
	case opcode.Plus:
		result, e.err = computePlus(a, b)
	case opcode.Minus:
		result, e.err = computeMinus(a, b)
	case opcode.Mul:
		result, e.err = computeMul(a, b)
	case opcode.Div:
		result, e.err = computeDiv(a, b)
	case opcode.Mod:
		result, e.err = computeMod(a, b)
	case opcode.IntDiv:
		result, e.err = computeIntDiv(a, b)
	default:
		e.err = errors.Errorf("invalid op %v in arithmetic operation", o.Op)
		return false
	}
	o.SetValue(result)
	return e.err == nil
}

func (e *Evaluator) handleArithmeticOp(o *ast.BinaryOperationExpr) bool {
	a, err := coerceArithmetic(types.RawData(o.L.GetValue()))
	if err != nil {
		e.err = errors.Trace(err)
		return false
	}

	b, err := coerceArithmetic(types.RawData(o.R.GetValue()))
	if err != nil {
		e.err = errors.Trace(err)
		return false
	}

	a, b = types.Coerce(a, b)
	if a == nil || b == nil {
		o.SetValue(nil)
		return true
	}

	var result interface{}
	switch o.Op {
	case opcode.Plus:
		result, e.err = computePlus(a, b)
	case opcode.Minus:
		result, e.err = computeMinus(a, b)
	case opcode.Mul:
		result, e.err = computeMul(a, b)
	case opcode.Div:
		result, e.err = computeDiv(a, b)
	case opcode.Mod:
		result, e.err = computeMod(a, b)
	case opcode.IntDiv:
		result, e.err = computeIntDiv(a, b)
	default:
		e.err = ErrInvalidOperation.Gen("invalid op %v in arithmetic operation", o.Op)
		return false
	}
	o.SetValue(result)
	return e.err == nil
}

func (e *Evaluator) handleXor(o *ast.BinaryOperationExpr) bool {
	leftVal := o.L.GetValue()
	righVal := o.R.GetValue()
	if types.IsNil(leftVal) || types.IsNil(righVal) {
		o.SetValue(nil)
		return true
	}
	x, err := types.ToBool(leftVal)
	if err != nil {
		e.err = errors.Trace(err)
		return false
	}

	y, err := types.ToBool(righVal)
	if err != nil {
		e.err = errors.Trace(err)
		return false
	}
	if x == y {
		o.SetValue(int64(0))
	} else {
		o.SetValue(int64(1))
	}
	return true
}

func (e *Evaluator) handleLogicOperation(o *ast.BinaryOperationExpr) bool {
	leftVal, err := types.Convert(o.L.GetValue(), o.GetType())
	if err != nil {
		e.err = err
		return false
	}
	rightVal, err := types.Convert(o.R.GetValue(), o.GetType())
	if err != nil {
		e.err = err
		return false
	}
	if leftVal == nil || rightVal == nil {
		o.SetValue(nil)
		return true
	}
	var boolVal bool
	switch o.Op {
	case opcode.AndAnd:
		boolVal = leftVal != zeroI64 && rightVal != zeroI64
	case opcode.OrOr:
		boolVal = leftVal != zeroI64 || rightVal != zeroI64
	case opcode.LogicXor:
		boolVal = (leftVal == zeroI64 && rightVal != zeroI64) || (leftVal != zeroI64 && rightVal == zeroI64)
	default:
		panic("should never happen")
	}
	if boolVal {
		o.SetValue(oneI64)
	} else {
		o.SetValue(zeroI64)
	}
	return true
}

func (e *Evaluator) handleBitOp(o *ast.BinaryOperationExpr) bool {
	a, b := types.Coerce(o.L.GetValue(), o.R.GetValue())

	if types.IsNil(a) || types.IsNil(b) {
		o.SetValue(nil)
		return true
	}

	x, err := types.ToInt64(a)
	if err != nil {
		e.err = errors.Trace(err)
		return false
	}

	y, err := types.ToInt64(b)
	if err != nil {
		e.err = errors.Trace(err)
		return false
	}

	// use a int64 for bit operator, return uint64
	switch o.Op {
	case opcode.And:
		o.SetValue(uint64(x & y))
	case opcode.Or:
		o.SetValue(uint64(x | y))
	case opcode.Xor:
		o.SetValue(uint64(x ^ y))
	case opcode.RightShift:
		o.SetValue(uint64(x) >> uint64(y))
	case opcode.LeftShift:
		o.SetValue(uint64(x) << uint64(y))
	default:
		e.err = ErrInvalidOperation.Gen("invalid op %v in bit operation", o.Op)
		return false
	}
	return true
}