Block dependencies are represented by DAGs and graph utility functions
topo_sort() and is_acyclic() are used to create a topological ordering
(implemented as DFS) of blocks and to check for cycles. An adjacency matrix
corresponding to a board is available as as.matrix().
Usage
# S3 method for class 'board'
is_acyclic(x)
# S3 method for class 'links'
is_acyclic(x)
topo_sort(x)
is_acyclic(x)
# S3 method for class 'matrix'
is_acyclic(x)Value
Topological ordering via topo_sort() returns a character vector
with sorted node IDs and the generic function is_acyclic() is expected to
return a scalar logical value.
Examples
brd <- new_board(
c(
a = new_dataset_block(),
b = new_dataset_block(),
c = new_scatter_block(),
d = new_subset_block()
),
list(from = c("a", "d"), to = c("d", "c"))
)
as.matrix(brd)
#> a b c d
#> a 0 0 0 1
#> b 0 0 0 0
#> c 0 0 0 0
#> d 0 0 1 0
topo_sort(brd)
#> [1] "b" "a" "d" "c"
is_acyclic(brd)
#> [1] TRUE