Display a call (or expression) as a tree.

Source: R/draw-tree.r

call_tree takes a quoted expression. ast does the quoting for you.

call_tree(x, width = getOption("width"))

ast(x)

Arguments

x

quoted call, list of calls, or expression to display

width

displays width, defaults to current width as reported by getOption("width")

Examples

call_tree(quote(f(x, 1, g(), h(i()))))
#> \- ()
#>   \- `f
#>   \- `x
#>   \-  1
#>   \- ()
#>     \- `g
#>   \- ()
#>     \- `h
#>     \- ()
#>       \- `i 
call_tree(quote(if (TRUE) 3 else 4))
#> \- ()
#>   \- `if
#>   \-  TRUE
#>   \-  3
#>   \-  4 
call_tree(expression(1, 2, 3))
#> \-  1
#> 
#> \-  2
#> 
#> \-  3 

ast(f(x, 1, g(), h(i())))
#> \- ()
#>   \- `f
#>   \- `x
#>   \-  1
#>   \- ()
#>     \- `g
#>   \- ()
#>     \- `h
#>     \- ()
#>       \- `i 
ast(if (TRUE) 3 else 4)
#> \- ()
#>   \- `if
#>   \-  TRUE
#>   \-  3
#>   \-  4 
ast(function(a = 1, b = 2) {a + b})
#> \- ()
#>   \- `function
#>   \- []
#>     \ a = 1
#>     \ b = 2
#>   \- ()
#>     \- `{
#>     \- ()
#>       \- `+
#>       \- `a
#>       \- `b
#>   \- []
#>  
ast(f()()())
#> \- ()
#>   \- ()
#>     \- ()
#>       \- `f