decoder2: decode array

[enghitalo]

35% faster than older decode in arrays

Starting benchmark...
max_iterations: 1000000

***Structure and maps***
 SPENT   362.428 ms in old_json.decode(Stru, json_data)!

 SPENT   136.917 ms in decoder2.decode[StructType[string]](json_data1)!
 SPENT    97.051 ms in old_json.decode(StructType[string], json_data1)!

 SPENT   176.960 ms in decoder2.decode[StructTypeOption[string]](json_data1)!
 SPENT   108.812 ms in old_json.decode(StructTypeOption[string], json_data1)!

 SPENT   152.319 ms in decoder2.decode[StructType[int]](json_data2)!
 SPENT    99.679 ms in old_json.decode(StructType[int], json_data2)!

 SPENT   127.676 ms in decoder2.decode[map[string]string](json_data1)!
 SPENT   208.413 ms in old_json.decode(map[string]string, json_data1)!


***arrays***
 SPENT   381.573 ms in decoder2.decode[[]int]('[1, 2, 3, 4, 5, 6, 7, 8, 9, 0]')!
 SPENT   589.276 ms in old_json.decode([]int, '[1, 2, 3, 4, 5, 6, 7, 8, 9, 0]')!


***simple types***
 SPENT    33.200 ms in decoder2.decode[int]('2')!
 SPENT    31.594 ms in decoder2.decode[bool]('true')!

[spytheman]

Excellent work.