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List Move Selectors

Route and sequence selectors for list planning variables.

List selectors operate on ordered list planning variables. They are the normal surface for vehicle routing, machine sequences, visit ordering, task queues, and other domains where position matters.

Baseline Route Selectors

For most route or sequence models, start with nearby relocation, nearby swap, and reverse:

[phases.move_selector]
type = "union_move_selector"
selection_order = "round_robin"

[[phases.move_selector.selectors]]
type = "nearby_list_change_move_selector"
variable_name = "visits"
max_nearby = 16

[[phases.move_selector.selectors]]
type = "nearby_list_swap_move_selector"
variable_name = "visits"
max_nearby = 16

[[phases.move_selector.selectors]]
type = "list_reverse_move_selector"
variable_name = "visits"

Relocation And Swap

Selector Move type Use
list_change_move_selector ListChangeMove move one list element to another position
nearby_list_change_move_selector ListChangeMove distance-pruned relocation
list_swap_move_selector ListSwapMove swap two list elements
nearby_list_swap_move_selector ListSwapMove distance-pruned swaps 
[phases.move_selector]
type = "nearby_list_change_move_selector"
variable_name = "visits"
max_nearby = 20

Nearby list selectors use list distance meters and stable tie ordering so seeded local search remains reproducible.

Sublist Selectors

Sublist selectors move or swap contiguous list segments. They are useful when a run of adjacent visits or tasks should stay together while moving elsewhere.

Selector Move type
sublist_change_move_selector SublistChangeMove
sublist_swap_move_selector SublistSwapMove 
[phases.move_selector]
type = "sublist_change_move_selector"
variable_name = "visits"
max_sublist_size = 4

Route Improvement

list_reverse_move_selector

Reverses a contiguous segment. Use it as the basic 2-opt style improvement for routes and ordered sequences.

[phases.move_selector]
type = "list_reverse_move_selector"
variable_name = "visits"

k_opt_move_selector

Performs K-opt route reconnection for routing-style list variables.

[phases.move_selector]
type = "k_opt_move_selector"
variable_name = "visits"
k = 3

List Ruin

list_ruin_move_selector removes a bounded number of list elements and reinserts them. Use it for large-neighborhood search when small route edits are not enough.

[phases.move_selector]
type = "list_ruin_move_selector"
variable_name = "visits"
ruin_size = 8

The current runtime skips empty owners during list-ruin sampling, so empty routes or sequences do not consume ruin attempts.

Move Types

Move type Selector family
ListChangeMove list change and nearby list change
ListSwapMove list swap and nearby list swap
SublistChangeMove sublist change
SublistSwapMove sublist swap
ListReverseMove list reverse
KOptMove K-opt
ListRuinMove list ruin

See Also