Kiwi

# Stdkiwi

Store's Do method takes parameters (other than the first two) as interface{} which means you can pass anything into it. This isn't very safe as this can cause many unwanted errors by either passing wrong number of params or the wrong type. Package github.com/sdslabs/kiwi/stdkiwi exists to solve the same issue.

# Port from kiwi.Store

stdkiwi.Store is fully compatible with kiwi.Store. The latter can be replaced by the former without breaking anything. Even for creating new store both the packages have same functions:

import (
  "github.com/sdslabs/kiwi"
  "github.com/sdslabs/kiwi/stdkiwi"
)

// ...

schema := kiwi.Schema{
  "key_one": "str",
  "key_two": "hash",
}

store, err := stdkiwi.NewStore(schema)
if err != nil {
  // handle error
}

if err := store.AddKey("key_three", "set"); err != nil {
  // handle error
}

jsondata, err := store.Export()
if err != nil {
  // handle error
}

# Type safe methods

Package stdkiwi registers all the standard value types and defines various types which can be used to invoke or Do actions with type safe methods.

Each of the value type has a different Go type defined in the stdkiwi package and a new value of that type can be created with the corresponding method. For example:

import (
  "fmt"

  "github.com/sdslabs/kiwi/stdkiwi"
)

// ...

keyTwo := store.Hash("key_two") // assumes "key_two" is a "hash"

// All actions for a set are defined as functions
// Let's say we want to insert into the set
if err := keyTwo.Insert("key", "val"); err != nil {
  // handle error
}

// Or checking if a key exists in the hash,
// return value is not an interface{} now either
exists, err := keyTwo.Has("key")
if err != nil {
  // handle error
}

fmt.Println(exists) // true

The value types registered with stdkiwi are:

Type Package Type Method
str github.com/sdslabs/kiwi/values/str Str Str
list github.com/sdslabs/kiwi/values/list List List
set github.com/sdslabs/kiwi/values/set Set Set
hash github.com/sdslabs/kiwi/values/hash Hash Hash
zset github.com/sdslabs/kiwi/values/zset Zset Zset
zhash github.com/sdslabs/kiwi/values/zhash Zhash Zhash

# Guards

Calling methods to create the special type basically assumes that type of value. Like calling store.List("key_one") assumes that "key_one" is a list where infact it can be any other type. As an additional layer of safety these types implement stdkiwi.Value interface which implements the Guard method.

Let's say "key_one" is of "str" type and store.List("key_one") would result in error when any action is invoked. To protect from this, you can call the Guard method which will panic in case of such event.

import "github.com/sdslabs/kiwi/stdkiwi"

// ...

keyOne := store.List("key_one")

keyOne.Guard() // Panics!

Tip

It is a good practice to call guard after creating the store when new instance of the application is created. If a store is created dynamically, use GuardE which is another version of Guard which returns the error instead of panicing.

← Add new value type →