/// <summary>
/// Converts the input equation string into a SIL_Equation recursive datastructure
/// </summary>
/// <param name="equation">basic input eqaution, must NOT contain any brackets!</param>
/// <returns>Converted equation class which can be calculated</returns>
static ISILObject ProcessEquation(string functionspace, string equationString, List <ISILObject> equations)
{
//always returns equation
if (!SIL_Math.IsEquation(equationString))
{
return(Retrieve_SIL_Object(functionspace, equationString, equations));
}
char[] separators = { '/', '*', '+', '-', '&', '|', '<', '>', '=' };
string leftVar = "",
rightVar = "",
equationSubstring = "";
int leftIndex = 0,
rightIndex = 0;
SILEquation equation = new SILEquation();
equationString = equationString.Trim();
//multiplication and division needs to be taken care of first!
List <OperatorPosition> firstPos = new List <OperatorPosition>();
for (int i = 0; i < separators.Length; i++)
{
int pos = equationString.IndexOf(separators[i]);
if (pos >= 0)
{
OperatorPosition op = new OperatorPosition();
op.position = pos;
op.c = separators[i];
firstPos.Add(op);
}
if (i == 1 && firstPos.Count > 0)
{
break;
}
}
firstPos.Sort(SortFirstOperators);
equation.Operation = ConvertToOperator(firstPos[0].c);
//now find the two terms this operation applies to and build new SIL_Equation class
//find left variable
for (int i = firstPos[0].position - 1; i >= 0; i--)
{
leftIndex = i;
if (SIL_Math.IsOperator(equationString[i]))
{
if (i == 1)
{
leftIndex--; //allow negative numbers
}
break;
}
leftVar += equationString[i];
}
leftVar = leftVar.Trim();
if (leftVar.Length == 0)
{
leftVar = "0";
}
else
{
leftVar = Reverse(leftVar); //reverse the string b/c I read it from right to left
}
equation.Argument1 = Retrieve_SIL_Object(functionspace, leftVar, equations);
//find right variable
for (int i = firstPos[0].position + 1; i < equationString.Length; i++)
{
if (SIL_Math.IsOperator(equationString[i]))
{
break;
}
rightIndex = i;
rightVar += equationString[i];
}
rightIndex++;
rightVar = rightVar.Trim();
if (rightVar.Length == 0)
{
rightVar = "0";
}
equation.Argument2 = Retrieve_SIL_Object(functionspace, rightVar, equations);
equationSubstring = equationString.Substring(leftIndex, rightIndex - leftIndex);
string leftPart = leftIndex > 0 ? equationString.Substring(0, leftIndex + 1) : "";
int rightLength = equationString.Length - rightIndex;
string rightPart = rightLength > 0 ? equationString.Substring(rightIndex, rightLength) : "";
equationString = leftPart +
"{" + equations.Count.ToString() + "}" +
rightPart;
equations.Add(equation);
return(ProcessEquation(functionspace, equationString, equations));
}
/// <summary>
/// FOR is basically 2 actions: LET and WHILE combined with incrementing equation
/// </summary>
/// <param name="unparsedArgs"></param>
/// <param name="parsedArgs"></param>
/// <param name="lineNumber"></param>
/// <returns></returns>
static ActionType FOR_Parse(string functionspace, string unparsedArgs, ref object[] parsedArgs, ref int lineNumber)
{
//FOR i = 3, i < 10, i = i + 1
//remove the FOR word
string parameters = unparsedArgs.Substring(4, unparsedArgs.Length - 4);
//validate and decompose the string
string[] split = parameters.Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries);
if (split.Length < 3)
{
throw new Exception("Incorrect syntax! Use \"FOR variable, condition, increment\"");
}
parsedArgs = new object[3];
Queue <SIL_Action> actions_ = new Queue <SIL_Action>();
//Create LET statement
object[] parsedArgsLET = null;
parserSymbols_["LET"](
functionspace,
"LET " + split[0], //we have to add "LET " string in front for parser to recognize this command as LET
ref parsedArgsLET,
ref lineNumber);
SIL_Action LETaction = new SIL_Action(ActionType.LET, parsedArgsLET, lineNumber, functionspace);
LETaction.OnAction += new SIL_Action.Action(exeAction_);
parsedArgs[0] = LETaction;
//Parse condition
try
{
SILEquation condition = (SILEquation)ExpressionParse(functionspace, split[1], new List <ISILObject>());
parsedArgs[1] = condition;
}
catch (Exception conidtionEx)
{
throw conidtionEx;
throw new Exception("Condition must be an equation");
}
//Parse increment
object[] parsedArgsINCREMENT = null;
parserSymbols_["LET"](
functionspace,
"LET " + split[2],
ref parsedArgsINCREMENT,
ref lineNumber);
SIL_Action INCREMENTaction = new SIL_Action(ActionType.LET, parsedArgsINCREMENT, lineNumber, functionspace);
INCREMENTaction.OnAction += new SIL_Action.Action(exeAction_);
//Parse everythig inside FOR block
SIL_Action action;
do
{
lineNumber++;
if (lineNumber >= sourceLines_.Length)
{
throw new Exception("NEXT expected!");
}
action = ParseNext(functionspace, ref lineNumber);
if (action != null)
{
actions_.Enqueue(action);
}
} while (action.ActionType != ActionType.NEXT);
//Add increment action last
actions_.Enqueue(INCREMENTaction);
parsedArgs[2] = actions_;
return(ActionType.FOR);
}