private AstItem ReadIfStatement(TokenIterator tokens)
{
tokens.PopExpected(TokenKind.If);
var expression = ReadExpression(tokens, TokenKind.CurlyBracketOpen);
tokens.PopExpected(TokenKind.CurlyBracketOpen);
var statements = ReadStatements(tokens);
tokens.PopExpected(TokenKind.CurlyBracketClose);
List <AstItem> elseStatements = null;
var current = tokens.Current();
if (current.Kind == TokenKind.Else)
{
tokens.PopExpected(TokenKind.Else);
tokens.PopExpected(TokenKind.CurlyBracketOpen);
elseStatements = ReadStatements(tokens);
tokens.PopExpected(TokenKind.CurlyBracketClose);
}
return(AstItem.IfStatement(expression, statements, elseStatements));
}