Localize Floating Glycan Parts

localize_floating_parts() attaches selected floating parts to caller-supplied parent nodes. The assignments are interpreted against the floating-part rows and canonical node identifiers returned by structure_floating_candidates().

Each selected parent must belong to the floating part's declared candidate domain. For an unrestricted {<floating>} part, that domain contains every feasible node outside its own component, including nodes in other floating components. Assignments must also be simultaneously compatible with occupied and potential acceptor linkage positions, acyclic, and ultimately connected to the main tree.

Selected virtual attachments become ordinary graph edges. Unassigned floating parts remain floating. The resulting structures are canonicalized, and candidate-parent indices for remaining parts are remapped to the new canonical complete-sequence order. Attaching one floating component to another merges their component metadata and can iteratively resolve newly singleton domains.

Missing values, vector positions, and names in structure-vector input are preserved. For graph input, glycan_id must be 1L, and selected edges are appended without canonicalizing or renumbering vertices.

Usage

localize_floating_parts(x, assignments)

Arguments

x

A glycan structure vector or a glycan igraph.

assignments

A data frame with integer columns glycan_id, part_id, and parent_node. Each (glycan_id, part_id) pair may occur at most once.

Value

An object of the same representation as x. Structure-vector output has the same length and names as x; graph output retains its vertex IDs and order.

Examples

glycan <- as_glycan_structure(
  "{Neu5Ac(a2-6)|2,3}Gal(b1-3)GalNAc(a1-"
)
assignments <- tibble::tibble(
  glycan_id = 1L,
  part_id = 1L,
  parent_node = 2L
)
localize_floating_parts(glycan, assignments)
#> <glycan_structure[1]>
#> [1] Neu5Ac(a2-6)Gal(b1-3)GalNAc(a1-
#> # Unique structures: 1