a b(c d), "x" do end

a b(c d), /x/ do end

a b(c d), /x/m do end

a b(c(d)), "x" do end

a b(c(d)), /x/ do end

a b(c(d)), /x/m do end

a b{c d}, "x" do end

a b{c d}, /x/ do end

a b{c d}, /x/m do end

a b{c(d)}, "x" do end

a b{c(d)}, /x/ do end

a b{c(d)}, /x/m do end