Perform delta (pullback) migration

Given a functor F: C → D (as a FinFunctor) and a D-set (ACSet on schema D), produce a C-set by pulling back along F.

Usage

delta_migrate(functor, source, result_type)

Arguments

functor

A FinFunctor from source schema to target schema

source

An ACSet on the target (codomain) schema

result_type

An acset_constructor for the result (source domain schema)

Value

An ACSet on the source (domain) schema

Examples

# Identity functor: delta migration copies the ACSet unchanged
cat_g <- FinCat(schema = SchGraph)
F_id <- FinFunctor(
  ob_map = list(V = "V", E = "E"),
  hom_map = list(src = "src", tgt = "tgt"),
  dom = cat_g, codom = cat_g
)
g <- path_graph(3)
g2 <- delta_migrate(F_id, g, Graph)
nv(g2) # 3
#> [1] 3
ne(g2) # 2
#> [1] 2