private List <VertexTerminator> getFirst(VertexNonterminal vn)
{
if (this.first.ContainsKey(vn))
{
return(this.first[vn]);
}
List <VertexTerminator> ret = new List <VertexTerminator>();
IEnumerable <GrammerRule> rulesAboutVn = this.GrammerRuleSet.Where(x => x.Left == vn);
foreach (GrammerRule rule in rulesAboutVn)
{
var firstv = rule.Right[0];
if (firstv.GetType() == typeof(VertexNonterminal))
{
if (firstv != vn)
{
ret.AddRange(getFirst((VertexNonterminal)firstv));
}
}
else
{
if (!ret.Contains(firstv))
{
ret.Add((VertexTerminator)firstv);
}
}
}
if (!this.first.ContainsKey(vn))
{
this.first.Add(vn, ret);
}
return(ret);
}
/// <summary>
/// 计算闭包，宽搜，在this.family.Register中被调用
/// </summary>
public void CalcClosure()
{
Queue <Item> queue = new Queue <Item>();
//所有圆点后为非终结符的项目入队
foreach (Item coreItem in this.items.Where(c => c.IsCore))
{
if (coreItem.AfterDot(0) != null && coreItem.AfterDot(0).GetType() == typeof(VertexNonterminal))
{
queue.Enqueue(coreItem);
}
}
while (queue.Count > 0) //宽搜
{
Item itemjToExpand = queue.Dequeue();
VertexNonterminal vnToExpand = (VertexNonterminal)itemjToExpand.AfterDot(0);
IEnumerable <GrammerRule> rulesForExpanding = this.family.Grammer.GrammerRuleSet.Where(c => c.Left == vnToExpand);
foreach (GrammerRule r in rulesForExpanding)
{
// 生成可能添加的project
Item projExpand = new Item()
{
Rule = r,
DotPosition = 0,
FowardSearch = GetFowardSearch(itemjToExpand, this.family.Grammer),
IsCore = false
};
Boolean projExist = false;
// 检查项目是否存在
foreach (Item projCurrent in this.items)
{
if (projCurrent.IsSameItemWith(projExpand))
{
// 存在则合并向前搜索符
projCurrent.CombineFowardSearch(projExpand);
projExist = true;
break;
}
}
if (!projExist)
{
// 不存在则添加，如果是非终结符开始，还需加到队列里
this.items.Add(projExpand);
if (projExpand.AfterDot(0).GetType() == typeof(VertexNonterminal))
{
queue.Enqueue(projExpand);
}
}
}
}
}
private void btnStartAnalysis_Click(object sender, EventArgs e)
{
if (analyzer == null)
{
MessageBox.Show("请先分析文法！", "无法测试", MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
}
listViewAnalysisProcess.Items.Clear();
analyzer.CombineBySameCore();
analyzer.OnAnalysisProcess = OnAnalysisProcess;
VertexNonterminal grammerTree = null;
try
{
grammerTree = analyzer.Test(txtTest.Text);
}
catch (TestFailedException ex)
{
MessageBox.Show(ex.Message, "测试失败", MessageBoxButtons.OK, MessageBoxIcon.Information, MessageBoxDefaultButton.Button1);
return;
}
}
public ProductionManager(string grammerContext, string[] deriver = null)
{
this.VertexNonterminalSet = new List <VertexNonterminal>();
this.VertexTerminatorSet = new List <VertexTerminator>();
this.GrammerRuleSet = new List <GrammerRule>();
List <String> textLines = grammerContext.Split(new String[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries).ToList();
if (textLines.Count == 0)
{
throw new IllegalGrammerException("语法为空");
}
if (deriver == null)
{
deriver = new String[] { "->", "→" }
}
;
foreach (var textLine in textLines)
{
int iComment = textLines.IndexOf("//");
string realTextLine = iComment >= 0 ? textLine.Substring(0, iComment) : textLine;
if (string.IsNullOrWhiteSpace(realTextLine))
{
continue;
}
string[] ruleArray = realTextLine.Split(deriver, StringSplitOptions.RemoveEmptyEntries);
if (ruleArray == null)
{
throw new IllegalGrammerException("无法分析的产生式");
}
string strLeft = ruleArray[0];
string[] strRights = ruleArray[1].Split('|');
if (strLeft.Length != 1 || strLeft.ToUpper() != strLeft)
{
throw new IllegalGrammerException("推导符左边应该为一个大写字母作为非终结符");
}
VertexNonterminal ruleLeft = this.AddVertexNonterminal(strLeft[0]);
foreach (string strRight in strRights)
{
List <Vertex> ruleRight = new List <Vertex>();
foreach (char charVertex in strRight)
{
if ('A' <= charVertex && charVertex <= 'Z')
{
ruleRight.Add(this.AddVertexNonterminal(charVertex));
}
else
{
ruleRight.Add(this.AddVertexTerminator(charVertex));
}
}
GrammerRule newRule = new GrammerRule(ruleLeft, ruleRight);
newRule.IsAcceptRule = false;
this.GrammerRuleSet.Add(newRule);
}
}
if (this.GrammerRuleSet.Count == 0)
{
throw new IllegalGrammerException("语法为空");
}
this.VertexTerminatorSet.Add(VertexTerminator.End);
this.GrammerRuleSet[0].IsAcceptRule = true;
}
public VertexNonterminal Test(string input)
{
Stack <Vertex> inputStack = new Stack <Vertex>();
inputStack.Push(VertexTerminator.End);
for (int i = input.Length - 1; i >= 0; i--)
{
inputStack.Push(new VertexTerminator(input[i]));
}
Stack <ItemSet> statusStack = new Stack <ItemSet>();
Stack <Vertex> letterStack = new Stack <Vertex>();
statusStack.Push(this.ItemFamily.FirstItemSet);
letterStack.Push(VertexTerminator.End);
while (true)
{
ItemSet currentStatus = statusStack.Peek();
Vertex currentInput = inputStack.Peek().UniformBy(grammer);
if (currentInput == null)
{
throw new TestFailedException("输入'" + inputStack.Peek() + "'符号不合法", inputStack, statusStack, letterStack);
}
if (currentStatus.ActionTable.ContainsKey(currentInput) == false)
{
throw new TestFailedException("无法找到合适的规约项或者移进项", inputStack, statusStack, letterStack);
}
Action action = currentStatus.ActionTable[currentInput];
if (OnAnalysisProcess != null && currentInput.GetType() == typeof(VertexTerminator))
{
OnAnalysisProcess(statusStack, letterStack, inputStack, action);
}
if (action.GetType() == typeof(GotoAction))
{
letterStack.Push(inputStack.Pop());
statusStack.Push(((GotoAction)action).ItemSet);
}
else
{ // AC 或者 规约
GrammerRule rule;
rule = ((ConvertionAction)action).Rule;
int length = rule.Right.Count;
VertexNonterminal vn = new VertexNonterminal(rule.Left.Name);
vn.Children = new List <Vertex>();
while (length > 0)
{
Vertex child = letterStack.Pop();
child.Father = vn;
vn.Children.Add(child);
statusStack.Pop();
length--;
}
vn.Children.Reverse();
if (((ConvertionAction)action).Acceptable)
{
return(vn);
}
else
{
inputStack.Push(vn);
}
}
}
}