| combo | Combobox to manipulate a string variable by offering a list of alternative expressions |
| entry | Text entry field to manipulate a string variable |
| filer | File selection dialog to manipulate a string variable denoting a filename |
| knob | Knob to manipulate a real valued variable |
| print.twiddlerControl | Display information about a twiddler control |
| shortenString | Shorten a string if it is longer than a limit |
| toggle | Checkbox to manipulate a logical variable |
| twiddle | Interactive manipulation of R expressions |
| twiddle_print | Print, then directly flush the output buffer |
| unboundVariables | Find the unbound variables of an R expression |