automat.cs

automat.cs

static private bool IsValidFormula(string formula) {
            // Ja bych byl pouzil Regexpy a mel to na tri radky, jenze to neprojde na cas, takze automat :///
            ValidatorState state = ValidatorState.START;
            if (formula[0] != '=')
            {
                return false;
            }

            for (int i = 1; i < formula.Length; i++)
            {
                if (Char.IsUpper(formula[i]))
                {
                    if (state == ValidatorState.START || state == ValidatorState.FIRSTCOORDCOL)
                    {
                        state = ValidatorState.FIRSTCOORDCOL;
                    }
                    else if (state == ValidatorState.OPERATOR)
                    {
                        state = ValidatorState.SECONDCOORDCOL;
                    }
                    else if (state != ValidatorState.SECONDCOORDCOL)
                    {
                        return false;
                    }
                }
                else if (Char.IsDigit(formula[i]))
                {
                    if (state == ValidatorState.OPERATOR || state == ValidatorState.START)
                    {
                        return false;
                    }
                    else if (state == ValidatorState.FIRSTCOORDCOL)
                    {
                        state = ValidatorState.FIRSTCOORDROW;
                    }
                    else if (state == ValidatorState.SECONDCOORDCOL)
                    {
                        state = ValidatorState.SECONDCOORDROW;
                    }
                }
                else if (formula[i] == '+' || formula[i] == '-' || formula[i] == '*' || formula[i] == '/')
                {
                    if (state == ValidatorState.FIRSTCOORDROW)
                    {
                        state = ValidatorState.OPERATOR;
                    }
                    else
                    {
                        return false;
                    }
                }
                else
                {
                    return false;
                }
            }

            if (state != ValidatorState.SECONDCOORDROW)
            {
                return false;
            }

            return true;
        }

        enum ValidatorState
        {
            START,
            FIRSTCOORDCOL,
            FIRSTCOORDROW,
            OPERATOR,
            SECONDCOORDCOL,
            SECONDCOORDROW,
        }