Remove old faulty Tane code

The Tane code never corrently implemented Tane, and keeping it has meant
having to add arguments to it whenever they're added to DFD equivalents,
so it's a deteriment to keep. When I do add Tane properly, it'll be from
scratch.

R/discover.r

@@ -563,82 +563,6 @@ find_LHSs_dfd <- function(
     )
 }
 
-find_LHSs_tane <- function(
-  rhs,
-  lhs_nonfixed_indices,
-  nodes,
-  simple_nodes,
-  partitions,
-  compute_partitions,
-  bijection_candidate_nonfixed_indices,
-  detset_limit,
-  store_cache = FALSE
-) {
-  # See find_LHSs_dfd for node categories, etc.
-  # Tane is a breadth-first search, going one powerset layer at a time. This
-  # greatly simplifies generating seeds, picking which node to check next, etc.,
-  # compared to DFD.
-
-  # change requires two steps to change at once:
-  # - change seed generation to move up one layer only, checking for no
-  #   supersets of min_deps;
-  # - iterate through all seeds instead of randomly picking just one, and
-  #   picking nodes for depth-first traversal from there;
-  # this forbids a node from being revisited, and from being inferrable
-  # everything after this is cleanup
-  seeds <- simple_nodes
-  min_deps <- integer()
-  bijection_nodes <- to_nodes(
-    match(
-      bijection_candidate_nonfixed_indices,
-      lhs_nonfixed_indices
-    ),
-    nodes
-  )
-
-  while (length(seeds) != 0) {
-    for (node in seeds) {
-      lhs_set <- lhs_nonfixed_indices[nodes$bits[[node]]]
-      cp <- compute_partitions(
-        rhs,
-        lhs_set,
-        partitions
-      )
-      result <- cp[[1]]
-      partitions <- cp[[2]]
-      if (result) {
-        min_deps <- c(min_deps, node)
-        nodes$category[node] <- 2L
-        if (is.element(node, bijection_nodes)) {
-          lhs_index <- lhs_nonfixed_indices[nodes$bits[[node]]]
-          stopifnot(is.element(
-            lhs_index,
-            bijection_candidate_nonfixed_indices
-          ))
-          if (store_cache)
-            return(list(lhs_index, partitions, TRUE))
-          else
-            return(list(lhs_index, TRUE))
-        }
-      }else{
-        nodes$category[[node]] <- -3L
-      }
-    }
-    seeds <- generate_next_seeds_tane(seeds, nodes, min_deps)
-  }
-  if (store_cache)
-    list(
-      lapply(min_deps, \(md) lhs_nonfixed_indices[nodes$bits[[md]]]),
-      partitions,
-      FALSE
-    )
-  else
-    list(
-      lapply(min_deps, \(md) lhs_nonfixed_indices[nodes$bits[[md]]]),
-      FALSE
-    )
-}
-
 pick_next_node <- function(node, nodes, trace, min_deps, max_non_deps) {
   if (nodes$category[node] == 3) { # candidate dependency
     s <- nonvisited_children(node, nodes)
@@ -721,24 +645,6 @@ generate_next_seeds <- function(max_non_deps, min_deps, lhs_attr_nodes, nodes, d
   remove_pruned_supersets(seeds, min_deps, nodes$bits)
 }
 
-generate_next_seeds_tane <- function(seeds, nodes, min_deps) {
-  nondep_seeds <- seeds[nodes$category[seeds] < 0L]
-  if (length(nondep_seeds) <= 1L)
-    return(integer())
-  old_level <- sum(nodes$bits[[nondep_seeds[[1L]]]])
-  all_bits <- which(Reduce(`|`, nodes$bits[nondep_seeds]))
-  unions <- apply(utils::combn(all_bits, old_level + 1L), 2, to_node, nodes)
-  uniq <- unique(unions)
-  Filter(
-    \(u) !any(vapply(
-      nodes$bits[min_deps],
-      \(sub) is_superset(nodes$bits[[u]], sub),
-      logical(1)
-    )),
-    uniq
-  )
-}
-
 cross_intersection <- function(seeds, max_non_dep, powerset, detset_limit) {
   new_seed_full_indices <- integer()
   for (dep in seeds) {

tests/testthat/test-discover.r

@@ -736,18 +736,6 @@ describe("discover", {
       terminates_then(is_valid_minimal_functional_dependency, 1)
     )
   })
-  # it("gives the same results with each method under full accuracy", {
-  #   forall(
-  #     gen_df(4, 6),
-  #     \(df) {
-  #       res1 <- withTimeout(discover(df, 1, method = "dfd"), timeout = 5, onTimeout = "silent")
-  #       expect_true(!is.null(res1))
-  #       res2 <- withTimeout(discover(df, 1, method = "tane"), timeout = 5, onTimeout = "silent")
-  #       expect_true(!is.null(res2))
-  #       expect_equiv_deps(res1, res2)
-  #     }
-  #   )
-  # })
 })
 
 describe("generate_next_seeds", {