/// <summary>
/// 解析一个Block
/// </summary>
/// <param name="Lex">词法分析器</param>
/// <returns>解析结果</returns>
private static ASTNode_StatementList ParseBlock(Lexer Lex)
{
ASTNode_StatementList tRet;
if (TryMatchToken(Lex, Lexer.Token.LeftBrace)) // {
{
tRet = ParseStatementList(Lex);
MatchToken(Lex, Lexer.Token.RightBrace); // }
return(tRet);
}
else // 单条语句
{
ASTNode_Statement tStatement;
if (ParseStatement(Lex, out tStatement))
{
tRet = new ASTNode_StatementList();
tRet.Statements.Add(tStatement);
return(tRet);
}
else
{
throw new SyntaxException(Lex.Position, Lex.Line, Lex.Row,
String.Format("unexpected token {0}.", Lex.FormatCurrentToken()));
}
}
}
/// <summary>
/// 解析一个块中的StatementList
/// </summary>
/// <param name="Lex">词法分析器</param>
/// <returns>解析结果</returns>
private static ASTNode_StatementList ParseStatementList(Lexer Lex)
{
ASTNode_StatementList tRet = new ASTNode_StatementList();
ASTNode_Statement tStatement;
while (ParseStatement(Lex, out tStatement))
{
tRet.Statements.Add(tStatement);
}
return(tRet);
}
/// <summary>
/// 执行一个区块
/// </summary>
/// <param name="StatementList">语句列表语法树</param>
public void ExecBlock(ASTNode_StatementList StatementList)
{
foreach (ASTNode_Statement s in StatementList.Statements)
{
switch (s.Type)
{
case ASTNode.ASTType.Assignment:
{
ASTNode_Assignment tAssignment = (ASTNode_Assignment)s;
object tResult = ExecExpression(tAssignment.Expression);
if (!_Environment.ContainsKey(tAssignment.IdentifierLower))
{
_Environment.Add(tAssignment.IdentifierLower, tResult);
}
else
{
_Environment[tAssignment.IdentifierLower] = tResult;
}
}
break;
case ASTNode.ASTType.Call:
{
ASTNode_Call tCall = (ASTNode_Call)s;
applyCallOperator(tCall.Identifier, tCall.IdentifierLower, tCall.ArgList, s.LineNumber);
}
break;
case ASTNode.ASTType.ForStatement:
{
ASTNode_ForStatement tForStatement = (ASTNode_ForStatement)s;
object tFromResult = ExecExpression(tForStatement.FromExpression);
object tToResult = ExecExpression(tForStatement.ToExpression);
object tStepResult = tForStatement.StepExpression == null ? null : ExecExpression(tForStatement.StepExpression);
doForLoop(
tForStatement.Identifier,
tForStatement.IdentifierLower,
tFromResult,
tToResult,
tStepResult,
tForStatement.ExecBlock,
s.LineNumber
);
}
break;
default:
throw new RuntimeException(s.LineNumber, "internal error.");
}
}
}
/// <summary>
/// 解析语法树
/// </summary>
/// <param name="Lex">词法分析器</param>
/// <returns>语法树</returns>
public static ASTNode_StatementList Parse(Lexer Lex)
{
Lex.Next(); // 预读取第一个词法单元
ASTNode_StatementList tRet = ParseStatementList(Lex);
if (Lex.CurrentToken != Lexer.Token.EOF)
{
throw new SyntaxException(Lex.Position, Lex.Line, Lex.Row,
String.Format("unexpected token {0}.", Lex.FormatCurrentToken()));
}
return(tRet);
}
/// <summary>
/// 提交源代码
/// </summary>
/// <param name="SourceCode">源代码</param>
public void SubmitSourceCode(string SourceCode)
{
if (_WorkThread != null && _WorkThread.IsAlive)
{
MessageBox.Show(this, "请先结束当前任务然后继续。", "正忙", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
if (SourceCode != _SourceCode)
{
_SourceCode = SourceCode;
_AST = null;
}
_WorkThread = new Thread(new ThreadStart(workThreadJob));
_WorkThread.IsBackground = true;
_WorkThread.Start();
}
// 执行for循环
private void doForLoop(string Identifier, string IdentifierLower, object From, object To, object Step, ASTNode_StatementList Block, int LineNumber)
{
if (!(From is double))
{
throw new RuntimeException(LineNumber, "from expression must return a digit.");
}
if (!(To is double))
{
throw new RuntimeException(LineNumber, "to expression must return a digit.");
}
double tFrom = (double)From;
double tTo = (double)To;
// 设置默认步长
if (Step == null)
{
if (tFrom <= tTo)
{
Step = 1.0;
}
else if (tFrom >= tTo)
{
Step = -1.0;
}
}
if (!(Step is double))
{
throw new RuntimeException(LineNumber, "step expression must return a digit.");
}
double tStep = (double)Step;
// 赋予初值
if (!_Environment.ContainsKey(IdentifierLower))
{
_Environment.Add(IdentifierLower, tFrom);
}
else
{
_Environment[IdentifierLower] = tFrom;
}
// 执行for循环
while (true)
{
// ！ 当前的值可能在循环体中被用户代码改变。
object tCurrentObject = fetchValueOfIdentifier(Identifier, IdentifierLower, LineNumber);
if (!(tCurrentObject is double))
{
throw new RuntimeException(LineNumber, "for iterator must be a digit.");
}
double tCurrent = (double)tCurrentObject;
// 检查循环是否结束
if (tFrom <= tTo && tCurrent > tTo)
{
break;
}
else if (tFrom > tTo && tCurrent < tTo)
{
break;
}
// 执行函数体
ExecBlock(Block);
// Step计数
// ！ 重新获取值
tCurrentObject = fetchValueOfIdentifier(Identifier, IdentifierLower, LineNumber);
if (!(tCurrentObject is double))
{
throw new RuntimeException(LineNumber, "for iterator must be a digit.");
}
tCurrent = (double)tCurrentObject + tStep;
// 设置值
if (!_Environment.ContainsKey(IdentifierLower))
{
_Environment.Add(IdentifierLower, tCurrent);
}
else
{
_Environment[IdentifierLower] = tCurrent;
}
}
}
// 工作线程
private void workThreadJob()
{
Stopwatch tWatch = new Stopwatch();
// 初始化状态
this.Invoke((Action)initState);
// 检查AST树是否已生成
if (_AST != null)
{
writeLog("忽略解析过程");
}
else
{
writeLog("正在执行解析过程...");
// 解析代码
bool bCompileSucceed = false;
using (StringReader tReader = new StringReader(_SourceCode))
{
tWatch.Start();
try
{
lang.Lexer tLexer = new lang.Lexer(tReader); // 初始化Lexer
_AST = lang.Syntax.Parse(tLexer); // 解析
bCompileSucceed = true;
}
catch (lang.LexcialException e)
{
writeLog("词法错误");
}
catch (lang.SyntaxException e)
{
writeLog("语法错误");
}
catch (Exception e)
{
writeLog("一般性错误");
}
tWatch.Stop();
if (bCompileSucceed)
{
writeLog("解析成功，耗时：{0} 秒");
}
else
{
writeLog("解析失败，耗时：{0} 秒");
}
}
}
if (_AST != null)
{
// 执行语法树
PaintRuntime tRT = new PaintRuntime();
tRT.OnOutputText += delegate(PaintRuntime sender, string Content)
{
//writeOutputText(Content + "\r\n");
};
tRT.OnRuntimeException += delegate(PaintRuntime sender, lang.RuntimeException e)
{
writeLog("运行时错误");
};
// 执行
writeLog("正在执行...");
tWatch.Start();
tRT.RunAST(_AST);
tWatch.Stop();
writeLog("执行完毕，耗时秒");
// 设置图片
this.Invoke((Action) delegate() {
pictureBox_result.BackgroundImage = Resource.Icon_Busy;//tRT.TargetBuffer;
pictureBox_result.Width = pictureBox_result.BackgroundImage.Width;
pictureBox_result.Height = pictureBox_result.BackgroundImage.Height;
});
}
}