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public static Parse ( List |
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| tokenList | List |
Token list. |
| curIndex | int | Current index. When this function exits, will be incremented to the past any tokens consumed by this method |
| owner | the equation that this node is part of. required to pull function delegates out of the dictionary | |
| Résultat | ||
/// <summary>
/// Parse the specified equationText.
/// </summary>
/// <param name="equationText">Equation text.</param>
public void Parse(string equationText)
{
//grab the equation text
TextEquation = equationText;
//straight up tokenize the equation: operators, numbers, parens, functions, params
List <Token> tokenList = Tokenize(equationText);
//sort out those tokens into a linked list of equation nodes
int index = 0;
BaseNode listRootNode = BaseNode.Parse(tokenList, ref index, this);
//take that linked list and bend it into a binary tree. Grab the root node
RootNode = listRootNode.Treeify();
}
/// <summary>
/// Parse a list of tokens into a linked list of equation nodes.
/// This will sort it out into a flat equation
/// </summary>
/// <param name="tokenList">Token list.</param>
/// <param name="curIndex">Current index. When this function exits, will be incremented to the past any tokens consumed by this method</param>
/// <param name="owner">the equation that this node is part of. required to pull function delegates out of the dictionary</param>
/// <returns>A basenode pointing at the head of a linked list parsed by this method</returns>
static public BaseNode Parse(List <Token> tokenList, ref int curIndex, Equation owner)
{
Debug.Assert(null != tokenList);
Debug.Assert(null != owner);
Debug.Assert(curIndex < tokenList.Count);
//first get a value, which will be a number, function, param, or equation node
BaseNode myNumNode = BaseNode.ParseValueNode(tokenList, ref curIndex, owner);
Debug.Assert(null != myNumNode);
//if there are any tokens left, get an operator
if (curIndex < tokenList.Count)
{
BaseNode myOperNode = BaseNode.ParseOperNode(tokenList, ref curIndex, owner);
if (null != myOperNode)
{
//add that node to the end of the list
myNumNode.AppendNextNode(myOperNode);
//If it was able to pull an operator out, there has to be a number after it.
if (curIndex >= tokenList.Count)
{
throw new FormatException("Can't end an equation with an operator.");
}
//Recurse into the parse function and sort out the rest of the tokens
BaseNode nextNode = BaseNode.Parse(tokenList, ref curIndex, owner);
Debug.Assert(null != nextNode);
//add that node to the end of the list
myOperNode.AppendNextNode(nextNode);
}
}
//return the head node that I found
return(myNumNode);
}
/// <summary>
/// Parse the specified tokenList and curIndex.
/// overloaded by child types to do there own specific parsing.
/// </summary>
/// <param name="tokenList">Token list.</param>
/// <param name="curIndex">Current index.</param>
/// <param name="owner">the equation that this node is part of. required to pull function delegates out of the dictionary</param>
protected override void ParseToken(List <Token> tokenList, ref int curIndex, Equation owner)
{
Debug.Assert(null != tokenList);
Debug.Assert(null != owner);
Debug.Assert(curIndex < tokenList.Count);
//parse the equation into our subnode
SubEquation = BaseNode.Parse(tokenList, ref curIndex, owner);
//if some smart ass types in () the parse method wouldve returned null.
//it should evaluate to 0 in that case, so create a number node and set the value.
if (null == SubEquation)
{
NumberNode fakeNode = new NumberNode();
fakeNode.NumberValue = 0.0f;
SubEquation = fakeNode;
}
Debug.Assert(null != SubEquation);
//treeify the subequation so we can solve it
SubEquation = SubEquation.Treeify();
Debug.Assert(null != SubEquation);
}
