| 이름 | 설명 |
|---|---|
| EnumerableExpression | Represents inner part of 'for' operator which looks like 'for ( name in vector )'. http://cran.r-project.org/doc/manuals/r-release/R-lang.html#for |
| Expression | Implements shunting yard algorithm of expression parsing. https://en.wikipedia.org/wiki/Shunting-yard_algorithm |
| NullExpression |