constructor

Constructor

A tiny tool to make data-parsing and constructing deadly easy.

Just write a few tags and no more loading code anymore. Example:

type LevelReward struct {
	MinLevel int32
	RewardId int64
}

type RewardCfg struct {
	ID      int64
	Mode    int32
	Value   int32
	Reward  int32
	Reward2 string         // 1:50001,11:50001,16:50001,21:50001,23:50001
	Rewards []*LevelReward `cvt:"from(Reward2)|split(,)|map(split(:,int32)|obj(LevelReward))|sort(MinLevel)"`
}

type RewardCfgs struct {
	Data []*RewardCfg
	Dict map[int64]*RewardCfg           `cvt:"from(Data)|dict(ID)"`
	Mode map[int32]map[int64]*RewardCfg `cvt:"from(Data)|group(Mode, dict(ID))"`
}


var tableCsv = `
ID,Mode,Value,Reward,Reward2,DESC
1,1,1,50001,"11:50002,1:50001,16:50003,21:50004,23:50005","第一档奖励"
2,1,3,50002,"1:50002,11:50002,16:50002,21:50002,23:50002","第二档奖励"
3,1,6,50003,"1:50003,11:50003,16:50003,21:50003,23:50003","第三档奖励"`


r := &RewardCfgs{}
LoadAndConstruct(r, &r.Data, tableCsv)

please check the unit tests for usage.

All supported converters:

• from(field)
  • input: none
  • output: field value
• from(field, [field]...)
  • input: struct field
  • output: slice of field values
• split(sep)
  • input: none
  • output: slice of string
• split(sep, converter)
  • input: string value
  • output: slice of value converted by converter
• select(idx)
  • input: slice
  • output: slice element at idx
• map(converter)
  • input: slice
  • output: slice of return value of converter
• dict(field)
  • input: slice of struct
  • output: dict with field as key and struct as value
• dict(key, val)
  • input: slice of slice
  • output: sub slice as input of key convertor and result as key, same to val.
• obj(type) / obj(type, [field,]...)
  • input: slice
  • output: instance of type with fields assigned from slice elements
• group(field)
  • input: slice of struct
  • output: dict fo slice of struct, with field as key
• group(field, reduce)
  • input: slice of struct
  • output: dict fo slice of struct, with field as key and slice reduced by reduce converter
• sort(field) / sort(field, desc)
  • input: slice of struct
  • output: slice sorted by field

Performance

• due to the heavy usage of reflection, it performs much worse than a hand-written loader, so it's not a good idea to use it to handle super large tables.

• Benchmark result:

Benchmark_LoadAndConstruct
Benchmark_LoadAndConstruct-8        1167          14942971 ns/op
Benchmark_LoadManually
Benchmark_LoadManually-8           47370             27035 ns/op