Merge pull request #301 from gustaphe/nothing

Allow `nothing` as a sentinel value in recipes

src/recipes.jl

@@ -39,7 +39,11 @@ function create_kw_body(func_signature::Expr)
                 @warn("Type annotations on keyword arguments not currently supported in recipes. Type information has been discarded")
             end
             push!(kw_body.args, :($k = kwargs[$(Meta.quot(k))]))
-            kw_dict[k] = v isa QuoteNode ? v.value : v
+            if v == :nothing
+                kw_dict[k] = nothing
+            else
+                kw_dict[k] = v isa QuoteNode ? v.value : v
+            end
         end
         args = args[2:end]
     end

test/recipe_test.jl

@@ -215,3 +215,16 @@ sum1 = MyModule.MySum(3, 4)
 @test latexify(:(2 + $(sum1)^2)) == raw"$2 + \left( 3 + 4 \right)^{2}$"
 @test latexify(:(2 - $(sum1))) == raw"$2 - \left( 3 + 4 \right)$"
 
+struct NothingThing end
+@latexrecipe function f(::NothingThing; keyword=nothing)
+    if isnothing(keyword)
+        return L"a"
+    elseif keyword == :nothing
+        return L"b"
+    end
+end
+@test latexify(NothingThing()) == raw"$a$"
+@test latexify(NothingThing(); keyword=nothing) == raw"$a$"
+@test latexify(NothingThing(); keyword=:nothing) == raw"$b$"
+
+