fixed #from_json in TransitionTable and TransitionMatrix

spec/TransitionMatrix_spec.cr

@@ -7,7 +7,7 @@ describe Markov::TransitionMatrix do
     true.should eq true
   end
 
-  it "#to_json, #from_json" do  
+  it "#to_json, #from_json with String" do  
     t = Markov::TransitionMatrix(String).new
     t.add "I"
     t.add "just"
@@ -18,6 +18,18 @@ describe Markov::TransitionMatrix do
     t["I"].should eq t_j["I"]
   end
 
+  it "#to_json, #from_json with Int32" do  
+    t = Markov::TransitionMatrix(Int32).new
+    t.add 1
+    t.add 2
+    t.add 3
+    t.add 4
+    j_t = t.to_json
+    puts j_t
+    t_j = Markov::TransitionMatrix(Int32).from_json j_t
+    t[2].should eq t_j[2]
+  end
+
   it "#add" do
     t = Markov::TransitionMatrix(String).new
     t.add "hey"

spec/TransitionTable_spec.cr

@@ -63,7 +63,7 @@ describe Markov::TransitionTable do
     is_transition_matrix.should eq(true)
   end
 
-  it "#to_json, #from_json" do 
+  it "#to_json, #from_json with strings" do 
     string_array = %w(some say the world will end in fire)
     normal_init_table = Markov::TransitionTable(String).new
     normal_init_table.fill string_array
@@ -73,6 +73,16 @@ describe Markov::TransitionTable do
     from_json_init_table["some"].should eq normal_init_table["some"]
   end
 
+  it "#to_json, #from_json with integers" do 
+    int_array = [0,1,2,3,4,5]
+    normal_init_table = Markov::TransitionTable(Int32).new
+    normal_init_table.fill int_array
+
+    normal_init_table_json = normal_init_table.to_json
+    from_json_init_table = Markov::TransitionTable(Int32).from_json normal_init_table_json
+    from_json_init_table[1].should eq normal_init_table[1]
+  end
+
   it "#reset" do   
     movie_one = %w(the great gatsby)
     movie_two = %w(great expectations)

src/markov/TransitionMatrix.cr

@@ -22,7 +22,9 @@ module Markov
         if pull.kind == :null
           pull.read_next
         else
-          hash[key] = V.new(pull) # V is the value type, as in `Hash(K, V)`
+          key = LinkType == String ? %("#{key}") : key # makes String compatible for json parsing
+          key_of_type = LinkType.from_json key
+          hash[key_of_type] = V.new(pull) # V is the value type, as in `Hash(K, V)`
         end
       end
       hash

src/markov/TransitionTable.cr

@@ -21,7 +21,9 @@ module Markov
         if pull.kind == :null
           pull.read_next
         else
-          hash[key] = TransitionMatrix(LinkType).new(pull)
+          key = LinkType == String ? %("#{key}") : key # makes String compatible for json parsing
+          key_of_type = LinkType.from_json key
+          hash[key_of_type] = TransitionMatrix(LinkType).new(pull) # V is the value type, as in `Hash(K, V)`
         end
       end
       hash