/// <summary> /// Evaluates the expression by appending all the sub-expressions. /// </summary> /// <returns></returns> public static object EvalInterpolated(InterpolatedExpr expr) { if (expr.Expressions == null || expr.Expressions.Count == 0) return string.Empty; string total = ""; foreach (var exp in expr.Expressions) { if (exp != null) { var val = exp.Evaluate(); var text = ""; var lobj = (LObject)val; text = lobj.GetValue().ToString(); total += text; } } return new LString(total); }
/// <summary> /// Visits the function call expression tree /// </summary> /// <param name="exp"></param> public object VisitInterpolated(InterpolatedExpr exp) { return null; }
/// <summary> /// Parses an interpolated token into a set of tokens making up an interpolated expression. /// </summary> /// <param name="t"></param> /// <returns></returns> public Expr ParseInterpolatedExpression(Token t) { var iexp = new InterpolatedExpr(); // Convert each token in the interpolated string, need to convert it into // it's own expression. var tokens = t.Value as List<TokenData>; foreach (var tokenData in tokens) { var token = tokenData.Token; Expr exp = null; // 1. true / false / "name" / 123 / null; if (token.IsLiteralAny()) { exp = token == Tokens.Null ? new ConstantExpr(LObjects.Null) : new ConstantExpr(TokenHelper.ConvertToLangLiteral(token)); this.SetupContext(exp, tokenData); _state.ExpressionCount++; } // 2. ${first + 'abc'} or ${ result / 2 + max } else if (token.Kind == TokenKind.Multi) { var tokenIterator = new TokenIterator(); var tokens2 = token.Value as List<TokenData>; tokenIterator.Init(tokens2, 1, 100); tokenIterator.Advance(); var exisiting = _tokenIt; // a. Temporarily set the token iterator for the parser to the one for the interpolation. _tokenIt = tokenIterator; // b. Now parse only the tokens supplied. exp = ParseExpression(null); // c. Reset the token iterator to the global one for the entire script. _tokenIt = exisiting; } iexp.Add(exp); } _tokenIt.Advance(); return iexp; }