[Port] fix induced_subgraph indexing with vector of Bools (#22)

* fix induced_subgraph indexing with vector of Bools

Currently both `getindex` and `induced_subgraph` handle `AbstractVector{Bool}` argument in a way inconsistent with Julia Base rules.

* add tests

Co-authored-by: Bogumił Kamiński <bkamins@sgh.waw.pl>

src/operators.jl

@@ -659,6 +659,10 @@ function induced_subgraph(g::T, vlist::AbstractVector{U}) where T <: AbstractGra
     return h, vmap
 end
 
+function induced_subgraph(g::AbstractGraph, vlist::AbstractVector{Bool})
+    length(vlist) == length(g) || throw(BoundsError(g, vlist))
+    return induced_subgraph(g, findall(vlist))
+end
 
 function induced_subgraph(g::AG, elist::AbstractVector{U}) where AG <: AbstractGraph{T} where T where U <: AbstractEdge
     h = zero(g)

test/operators.jl

@@ -273,6 +273,14 @@
         @test h2 == h
         @test vm == collect(r)
         @test h2 == g[r]
+
+        r2 = falses(length(g))
+        r2[r] .= true
+        h2, vm = @inferred(induced_subgraph(g, r2))
+        @test h2 == h
+        @test vm == findall(r2)
+        @test h2 == g[r2]
+
     end
 
     g10 = complete_graph(10)
@@ -285,6 +293,12 @@
         @test sg2 == sg
         @test vm[4] == 8
 
+        bv = falses(length(g))
+        bv[5:8] .= true
+        sg2, vm = @inferred(induced_subgraph(g, bv))
+        @test sg2 == sg
+        @test vm[4] == 8
+
         elist = [
           SimpleEdge(1, 2), SimpleEdge(2, 3), SimpleEdge(3, 4),
           SimpleEdge(4, 5), SimpleEdge(5, 1)