/// <summary>
/// Take each token string from the list of postfixedtokens and build a parse tree
/// with each node evaluated when possible.
/// </summary>
internal void AppendFunction(IToken token)
{
int numberOfChildLeafs =0;
FunctionToken functToken= null;
switch (token.Type) {
case TokenType.function:
functToken = (FunctionToken)token;
numberOfChildLeafs = functToken.numberOfChildren;
break;
case TokenType.infixOperator:
numberOfChildLeafs = 2;
break;
case TokenType.suffixOperator:
numberOfChildLeafs = 1;
break;
}
//TODO: In the parser you must keep count of the amount of children and pass that number here
//also have restrictions in certain cases
string tokenString = token.TokenString;
TreeNode child = new TreeNode();
child.type = nodeType.operation;
child.name = tokenString;
TreeNode[] childLeafNodes = new TreeNode[numberOfChildLeafs];
for (int i = 0; i < numberOfChildLeafs; i++) {
if (children.Count() == 0)
throw new Exception("Post fixed token notation error.");
childLeafNodes[i] = children[0];
children.RemoveAt(0);
child.children.Insert(0, childLeafNodes[i]);
}
if (childLeafNodes.All(i => i.numericalEvaluation)) {
child.numericalEvaluation = true;
List<Complex> paramaters = childLeafNodes.Select(i => i.val).ToList();
if (token.Type == TokenType.suffixOperator || token.Type == TokenType.infixOperator)
child.val = postFixedOperatorEvaluator(paramaters, tokenString);
else if (token.Type == TokenType.function) {
//TODO: You should be evaluating parse trees not Complex values
child.val = functToken.Function.Compute(paramaters);
} else
throw new Exception("Not operator or function can't evaluate");
}
flattenTieredAddOrMult(child);
children.Insert(0, child);
}
/// <summary>
/// For commutative operations its possible to have one operation node with many children
/// instead of tiered iterations of the operation. This method is to change from the
/// latter to the former.</summary>
private void flattenTieredAddOrMult(TreeNode node)
{
TreeNode adjustedNode = new TreeNode();
switch (node.name) {
case "+":
for (int i = 0; i < node.children.Count(); i++) {
if (node.children[i].name == "+") {
adjustedNode = node.children[i];
node.children.RemoveAt(i);
foreach (TreeNode t in adjustedNode.children) {
node.children.Add(t);
}
}
}
break;
case "*":
List<int> commonFactors = new List<int>();
for(int i=0; i < node.children.Count(); i++){
if (node.children[i].name == "*") {
adjustedNode = node.children[i];
node.children.RemoveAt(i);
foreach (TreeNode t in adjustedNode.children) {
node.children.Add(t);
}
}
}
if (this.numericalEvaluation) {
//this means that all the children are numbers and we have evaluated
//TODO: take out the common factors from val.factors
//Make it work by using exponents
}
break;
}
}
internal bool AppendVariable(string variableName)
{
TreeNode child = new TreeNode();
child.type = nodeType.number;
switch (variableName) {
case "PI":
child.val = PI.value;
child.name = child.val.ToString();
break;
default:
ErrorLog.Add(new ErrorMessage("Unknown variable can't be appendend"));
return false;
}
child.numericalEvaluation = true;
children.Insert(0, child);
//clear the static visualization output string:
output = string.Empty;
return true;
}
internal void AppendNumber(NumberToken token)
{
Complex tokenVal = token.TokenNumValue;
TreeNode child = new TreeNode();
child.type = nodeType.number;
child.val = tokenVal;
child.name = tokenVal.ToString();
child.numericalEvaluation = true;
children.Insert(0, child);
//clear the static visualization output string:
output = string.Empty;
}
internal bool AppendKeyword(string keyword)
{
TreeNode child = new TreeNode();
child.type = nodeType.number;
switch (keyword) {
case "ANS":
Complex tokenVal = (Complex)OutputLog.returnValues.Last();
child.val = tokenVal;
child.name = tokenVal.ToString();
break;
default:
ErrorLog.Add(new ErrorMessage("Unknown variable can't be appendend"));
return false;
}
child.numericalEvaluation = true;
children.Insert(0, child);
//clear the static visualization output string:
output = string.Empty;
return true;
}
public TreeNode BuildParseTree() {
TreeNode parseTree = new TreeNode();
foreach (IToken token in InAList) {
switch (token.Type) {
case TokenType.keyword:
if (!parseTree.AppendKeyword(token.TokenString))
return null;
break;
case TokenType.number:
parseTree.AppendNumber((NumberToken)token);
break;
case TokenType.infixOperator:
parseTree.AppendFunction(token);
break;
case TokenType.suffixOperator:
parseTree.AppendFunction(token);
break;
case TokenType.variable:
if (!parseTree.AppendVariable(token.TokenString.ToUpper())) {
return null;
}
break;
case TokenType.function:
parseTree.AppendFunction((FunctionToken)token);
break;
default:
ErrorLog.Add(new ErrorMessage("Fatal parsing error: this token type is unknown cannot be appended to the parse tree"));
return null;
}
}
if (parseTree.children.Count() > 0)
//The root node is always redundant by construction
return parseTree.children.First();
else return null;
}
