Create a foodweb

A foodweb object describes the relationship of functions in an environment. It has two components: funmat (function matrix) which encodes the caller/callee relationships (i.e. which functions call which) and graphviz_spec which is a text representation of the graph and is used for the default plotting behaviour.

foodweb(
  FUN = NULL,
  env = parent.frame(),
  filter = !is.null(FUN),
  as.text = FALSE
)

Arguments

FUN

A function.

env

An environment, parent.frame() by default. Ignored if FUN is not NULL.

filter

Boolean. If TRUE, only functions that are direct descendants or antecedents of FUN will be shown.

as.text

Boolean. If TRUE, rather than rendering the graph the intermediate graphviz specification is returned.

Value

If as.text is TRUE, a character vector. Otherwise, a foodweb object as described above.

Details

foodweb() looks at the global environment by default. If you want to look at another environment you can either pass a function to the FUN argument of foodweb() or pass an environment to the env argument. If FUN is provided then the value of env is ignored, and the environment of FUN will be used.

Examples

# Create some functions to look at
f <- function() 1
g <- function() f()
h <- function() {
  f()
  g()
}
i <- function() {
  f()
  g()
  h()
}
j <- function() j()

x <- foodweb()
x
#> # A `foodweb`: 5 vertices and 7 edges 
#> digraph 'foodweb' {
#>   f()
#>   g() -> { f() }
#>   h() -> { f(), g() }
#>   i() -> { f(), g(), h() }
#>   j() -> { j() }
#> }

# You can access the components directly or via getter functions
x$funmat
#> # A foodweb matrix: 5 functions and 7 links
#>       CALLEE
#> CALLER f g h i j
#>      f 0 0 0 0 0
#>      g 1 0 0 0 0
#>      h 1 1 0 0 0
#>      i 1 1 1 0 0
#>      j 0 0 0 0 1
get_graphviz_spec(x)
#> digraph 'foodweb' {
#>   "f()"
#>   "g()" -> { "f()" }
#>   "h()" -> { "f()", "g()" }
#>   "i()" -> { "f()", "g()", "h()" }
#>   "j()" -> { "j()" }
#> }

# Calculate the foodweb of a function in another package
foodweb(glue::glue)
#> # A `foodweb`: 14 vertices and 13 edges 
#> digraph 'foodweb' {
#>   glue() -> { glue_data() }
#>   color_transformer() -> { glue() }
#>   glue_col() -> { glue() }
#>   glue_safe() -> { glue() }
#>   glue_sql() -> { glue() }
#>   glue_data() -> { %||%(), as_glue(), bind_args(), drop_null(), has_names(), recycle_columns(), trim() }
#>   %||%()
#>   as_glue()
#>   bind_args() -> { delayed_assign() }
#>   drop_null()
#>   has_names()
#>   recycle_columns()
#>   trim()
#>   delayed_assign()
#> }