Merge pull request #380 from JuliaRobotics/feature/20Q2/ls2

Feature ls2 close #332

Author: dehann

src/DistributedFactorGraphs.jl

@@ -191,7 +191,7 @@ export mergeVariableData!, mergeGraphVariableData!
 export natural_lt, sortDFG
 
 ## List
-export ls, lsf
+export ls, lsf, ls2
 export lsTypes, lsfTypes
 export lsWho, lsfWho
 export isPrior, lsfPriors
@@ -224,7 +224,7 @@ export
     compareFactorGraphs
 
 
-## Deprecated exports should be listed in Deprecated.jl if possible, otherwise here 
+## Deprecated exports should be listed in Deprecated.jl if possible, otherwise here
 
 
 ## needsahome.jl

src/services/AbstractDFG.jl

@@ -538,6 +538,15 @@ function lsf(dfg::G, ::Type{T}) where {G <: AbstractDFG, T <: FunctorInferenceTy
     ls(dfg, T)
 end
 
+"""
+    $(SIGNATURES)
+Helper to return neighbors at distance 2 around a given node label.
+"""
+function ls2(dfg::AbstractDFG, label::Symbol)
+    l2 = getNeighborhood(dfg, label, 2)
+    l1 = getNeighborhood(dfg, label, 1)
+    return setdiff(l2, l1)
+end
 
 """
     $SIGNATURES

test/testBlocks.jl

@@ -30,8 +30,8 @@ end
 Base.:(==)(a::TestCCW, b::TestCCW) = a.usrfnc! == b.usrfnc!
 
 
-global testDFGAPI = LightDFG
 global testDFGAPI = GraphsDFG
+global testDFGAPI = LightDFG
 
 #test Specific definitions
 # struct TestInferenceVariable1 <: InferenceVariable end
@@ -731,6 +731,7 @@ function testGroup!(fg, v1, v2, f0, f1)
         @test getVariableType(v1) == TestSofttype1()
         @test getVariableType(fg,:a) == TestSofttype1()
 
+        @test ls2(fg, :a) == [:b]
 
         #TODO what is lsTypes supposed to return?
         @test_broken lsTypes(fg)