Merge pull request #371 from probcomp/alexlew-has-submap

Add `has_submap`  method for ChoiceMaps (#124)

Author: marcoct

src/choice_map.jl

@@ -30,6 +30,13 @@ no value exists. A syntactic sugar is `Base.getindex`:
 """
 function get_value end
 
+"""
+    has_submap(choices::ChoiceMap, addr)
+
+Return true if there is a non-empty sub-assignment at the given address.
+"""
+function has_submap end
+
 """
     key_submap_iterable = get_submaps_shallow(choices::ChoiceMap)
 
@@ -69,6 +76,8 @@ function Base.isempty(::ChoiceMap)
     true
 end
 
+
+@inline has_submap(choices::ChoiceMap, addr) = !has_value(choices, addr) && !isempty(get_submap(choices, addr))
 @inline get_submap(choices::ChoiceMap, addr) = EmptyChoiceMap()
 @inline has_value(choices::ChoiceMap, addr) = false
 @inline get_value(choices::ChoiceMap, addr) = throw(KeyError(addr))
@@ -323,6 +332,7 @@ end
 
 export ChoiceMap
 export get_address_schema
+export has_submap
 export get_submap
 export get_value
 export has_value

test/assignment.jl

@@ -267,23 +267,29 @@ end
     # overwrite value with a submap
     choices = choicemap()
     choices[:x] = 1
+    @test has_value(choices, :x)
+    @test !has_submap(choices, :x)
     submap = choicemap(); submap[:y] = 2
     set_submap!(choices, :x, submap)
     @test !has_value(choices, :x)
     @test !isempty(get_submap(choices, :x))
+    @test has_submap(choices, :x)
 
     # overwrite subassignment with a value
     choices = choicemap()
     choices[:x => :y] = 1
     choices[:x] = 2
     threw = false
+    @test !has_submap(choices, :x)
     try get_submap(choices, :x) catch KeyError threw = true end
     @test threw
     @test choices[:x] == 2
 
     # overwrite subassignment with a subassignment
     choices = choicemap()
     choices[:x => :y] = 1
+    @test has_submap(choices, :x)
+    @test !has_submap(choices, :x => :y)
     submap = choicemap(); submap[:z] = 2
     set_submap!(choices, :x,  submap)
     @test !isempty(get_submap(choices, :x))