Microsoft.R.Core.AST.Variables.Variable.Parse C# (CSharp) Method

        public override bool Parse(ParseContext context, IAstNode parent) {
            RToken currentToken = context.Tokens.CurrentToken;
            Debug.Assert(currentToken.IsVariableKind());

            // Not calling base since expression parser will decide 
            // what parent node the variable belongs to.
            this.Token = currentToken;
            context.Tokens.MoveToNextToken();

            return true;
        }

        public override bool Parse(ParseContext context, IAstNode parent) {
            TokenStream<RToken> tokens = context.Tokens;

            if (tokens.CurrentToken.IsVariableKind()) {
                var v = new Variable();
                v.Parse(context, this);

                // Variables don't set parent since during complex
                // exression parsing parent is determined by the
                // expression parser based on precedence and grouping.
                v.Parent = this; 
                this.Variable = v;

                if (tokens.CurrentToken.IsKeywordText(context.TextProvider, "in")) {
                    this.InOperator = new TokenNode();
                    this.InOperator.Parse(context, this);

                    this.Expression = new Expression(inGroup: true);
                    if (this.Expression.Parse(context, this)) {
                        return base.Parse(context, parent);
                    }
                } else {
                    context.AddError(new MissingItemParseError(ParseErrorType.InKeywordExpected, tokens.CurrentToken));
                }
            } else {
                context.AddError(new MissingItemParseError(ParseErrorType.IndentifierExpected, tokens.PreviousToken));
            }

            return false;
        }