コード例 #1
0
ファイル: ExprParser.cs プロジェクト: GHLabs/SambaPOS-3
		public Expr OnParseIf()
        {
            var tokenIt = this._parser.TokenIt;
            var initiatorToken = tokenIt.NextToken;
            var expr = new IfExpr();
            // <codeIf>
            tokenIt.Expect(Tokens.If);

            // Parse the if
            this.ParseConditionalBlock(expr);
            tokenIt.AdvancePastNewLines();

            // Handle "else if" and/or else
            if (tokenIt.NextToken.Token == Tokens.Else)
            {
                // tokenIt.NextToken = "else"
                tokenIt.Advance();
                tokenIt.AdvancePastNewLines();

                // What's after else? 
                // 1. "if"      = else if statement
                // 2. "{"       = multi  line else
                // 3. "nothing" = single line else
                // Peek 2nd token for else if.
                var token = tokenIt.NextToken;
                if (tokenIt.NextToken.Token == Tokens.If)
                {
                    expr.Else = OnParseIf() as BlockExpr;
                }
                else // Multi-line or single line else
                {
                    var elseStmt = new BlockExpr();
                    this._parser.ParseBlock(elseStmt);
                    this._parser.SetupContext(elseStmt, token);
                    expr.Else = elseStmt;
                }
            }
            // </codeIf>
			this._parser.SetupContext(expr, initiatorToken);
			return expr;
		}
コード例 #2
0
ファイル: Execution.cs プロジェクト: GHLabs/SambaPOS-3
 /// <summary>
 /// Execute
 /// </summary>
 public object VisitIf(IfExpr expr)
 {
     // Case 1: If is true
     var result = expr.Condition.Evaluate(this) as LObject;
     bool execIf = EvalHelper.IsTrue(result);
     object returnVal = LObjects.Null;
     if (execIf)
     {
         
         if (expr.Statements != null && expr.Statements.Count > 0)
         {
             foreach (var stmt in expr.Statements)
             {
                 returnVal = stmt.Evaluate(this);
             }
         }
     }
     // Case 2: Else available to execute
     else if (expr.Else != null)
     {
         returnVal = expr.Else.Evaluate(this);
     }
     return returnVal;
 }
コード例 #3
0
ファイル: Visitor.cs プロジェクト: GHLabs/SambaPOS-3
 /// <summary>
 /// Visits the if statement tree.
 /// </summary>
 /// <param name="ifExpr"></param>
 public object VisitIf(IfExpr expr)
 {
     _callBackOnNodeStart(expr);
     expr.Condition.Visit(this);
     foreach (var stmt in expr.Statements)
     {
         stmt.Visit(this);
     }
     if (expr.Else != null)
         expr.Else.Visit(this);
     return null;
 }