Function calculate

calc.go:1337–1391

calculate evaluate basic arithmetic operations.

(opdStack *Stack, opt efp.Token)

// calculate evaluate basic arithmetic operations.
func calculate(opdStack *Stack, opt efp.Token) error {
	if opt.TValue == "-" && opt.TType == efp.TokenTypeOperatorPrefix {
		if opdStack.Len() < 1 {
			return ErrInvalidFormula
		}
		opd := opdStack.Pop().(formulaArg)
		opdStack.Push(newNumberFormulaArg(0 - opd.ToNumber().Number))
	}
	if opt.TValue == "-" && opt.TType == efp.TokenTypeOperatorInfix {
		if opdStack.Len() < 2 {
			return ErrInvalidFormula
		}
		rOpd := opdStack.Pop().(formulaArg)
		lOpd := opdStack.Pop().(formulaArg)
		if err := calcSubtract(rOpd, lOpd, opdStack); err != nil {
			return err
		}
	}
	tokenCalcFunc := map[string]func(rOpd, lOpd formulaArg, opdStack *Stack) error{
		"^":  calcPow,
		"*":  calcMultiply,
		"/":  calcDiv,
		"+":  calcAdd,
		"=":  calcEq,
		"<>": calcNEq,
		"<":  calcL,
		"<=": calcLe,
		">":  calcG,
		">=": calcGe,
		"&":  calcSplice,
	}
	if fn, ok := tokenCalcFunc[opt.TValue]; ok {
		if opdStack.Len() < 2 {
			return ErrInvalidFormula
		}
		rOpd := opdStack.Pop().(formulaArg)
		lOpd := opdStack.Pop().(formulaArg)
		if opt.TValue != "&" {
			if rOpd.Value() == "" {
				rOpd = newNumberFormulaArg(0)
			}
			if lOpd.Value() == "" {
				lOpd = newNumberFormulaArg(0)
			}
		}
		if rOpd.Type == ArgError {
			return errors.New(rOpd.Value())
		}
		if lOpd.Type == ArgError {
			return errors.New(lOpd.Value())
		}
		return fn(rOpd, lOpd, opdStack)
	}
	return nil
}

// parseOperatorPrefixToken parse operator prefix token.
func (f *File) parseOperatorPrefixToken(optStack, opdStack *Stack, token efp.Token) (err error) {