Mnemonix

v0.10.0

Mnemonix v0.10.0 Mnemonix.Features.Bump View Source

Functions to increment/decrement integer values within a store.

All of these functions are available on the main Mnemonix module.

Link to this section Summary

Types

bump_op()

The return value of a bump operation

Functions

bump(store, key, amount)

Adds amount to the value of the integer entry under key in store

bump!(store, key, amount)

Adds amount to the value of the integer entry under key in store

decrement(store, key)

Decrements the value of the integer entry under key in store by 1

decrement(store, key, amount)

Decrements the value of the integer entry under key in store by amount

increment(store, key)

Increments the value of the integer entry under key in store by 1

increment(store, key, amount)

Increments the value of the integer entry under key in store by amount

Link to this section Types

Link to this type bump_op() View Source 
bump_op() :: :ok | {:error, :no_integer}

The return value of a bump operation.

Link to this section Functions

Link to this function bump(store, key, amount) View Source 
bump(Mnemonix.store(), Mnemonix.key(), amount :: term()) ::
  bump_op() |
  no_return()

Adds amount to the value of the integer entry under key in store.

If the key does not exist, it is set to 0 before performing the operation.

If the amount or the value under key is not an integer, returns {:error, :no_integer}, otherwise returns :ok, and the value will remain unchanged.

Examples 

iex> store = Mnemonix.new(%{a: 1})
iex> Mnemonix.bump(store, :a, 1)
:ok
iex> Mnemonix.get(store, :a)
2

iex> store = Mnemonix.new
iex> Mnemonix.bump(store, :b, 2)
:ok
iex> Mnemonix.get(store, :b)
2

iex> store = Mnemonix.new(%{c: "foo"})
iex> Mnemonix.bump(store, :c, 3)
{:error, :no_integer}

iex> store = Mnemonix.new
iex> Mnemonix.bump(store, :c, "foo")
{:error, :no_integer}
Link to this function bump!(store, key, amount) View Source 
bump!(Mnemonix.store(), Mnemonix.key(), amount :: term()) ::
  :ok |
  no_return()

Adds amount to the value of the integer entry under key in store.

If the key does not exist, it is set to 0 before performing the operation.

If the amount or the value under key is not an integer, raises an ArithmeticError, and the value will remain unchanged.

Examples 

iex> store = Mnemonix.new(%{a: 1})
iex> Mnemonix.bump!(store, :a, 2)
:ok
iex> Mnemonix.get(store, :a)
3

iex> store = Mnemonix.new
iex> Mnemonix.bump!(store, :b, 2)
:ok
iex> Mnemonix.get(store, :b)
2

iex> store = Mnemonix.new(%{c: "foo"})
iex> Mnemonix.bump!(store, :c, 2)
** (ArithmeticError) value at key :c is not an integer

iex> store = Mnemonix.new
iex> Mnemonix.bump!(store, :d, "foo")
** (ArithmeticError) value provided to operation is not an integer
Link to this function decrement(store, key) View Source 
decrement(Mnemonix.store(), Mnemonix.key()) ::
  Mnemonix.store() |
  no_return()

Decrements the value of the integer entry under key in store by 1.

If the key does not exist, it is set to 0 before performing the operation.

If the value under key is not an integer, returns store unchanged.

Examples 

iex> store = Mnemonix.new(%{a: 1})
iex> Mnemonix.decrement(store, :a)
iex> Mnemonix.get(store, :a)
0

iex> store = Mnemonix.new
iex> Mnemonix.decrement(store, :b)
iex> Mnemonix.get(store, :b)
-1

iex> store = Mnemonix.new(%{c: "foo"})
iex> Mnemonix.decrement(store, :c)
iex> Mnemonix.get(store, :c)
"foo"
Link to this function decrement(store, key, amount) View Source 
decrement(Mnemonix.store(), Mnemonix.key(), amount :: term()) ::
  Mnemonix.store() |
  no_return()

Decrements the value of the integer entry under key in store by amount.

If the key does not exist, it is set to 0 before performing the operation.

If amount or the value under key is not an integer, returns store unchanged.

Examples 

iex> store = Mnemonix.new(%{a: 2})
iex> Mnemonix.decrement(store, :a, 2)
iex> Mnemonix.get(store, :a)
0

iex> store = Mnemonix.new
iex> Mnemonix.decrement(store, :b, 2)
iex> Mnemonix.get(store, :b)
-2

iex> store = Mnemonix.new(%{c: "foo"})
iex> Mnemonix.decrement(store, :c, 2)
iex> Mnemonix.get(store, :c)
"foo"

iex> store = Mnemonix.new
iex> Mnemonix.decrement(store, :d, "foo")
iex> Mnemonix.get(store, :d)
0
Link to this function increment(store, key) View Source 
increment(Mnemonix.store(), Mnemonix.key()) ::
  Mnemonix.store() |
  no_return()

Increments the value of the integer entry under key in store by 1.

If the key does not exist, it is set to 0 before performing the operation.

If the value under key is not an integer, returns store unchanged.

Examples 

iex> store = Mnemonix.new(%{a: 1})
iex> Mnemonix.increment(store, :a)
iex> Mnemonix.get(store, :a)
2

iex> store = Mnemonix.new
iex> Mnemonix.increment(store, :b)
iex> Mnemonix.get(store, :b)
1

iex> store = Mnemonix.new(%{c: "foo"})
iex> Mnemonix.increment(store, :c)
iex> Mnemonix.get(store, :c)
"foo"
Link to this function increment(store, key, amount) View Source 
increment(Mnemonix.store(), Mnemonix.key(), amount :: term()) ::
  Mnemonix.store() |
  no_return()

Increments the value of the integer entry under key in store by amount.

If the key does not exist, it is set to 0 before performing the operation.

If the amount or the value under key is not an integer, returns store unchanged.

Examples 

iex> store = Mnemonix.new(%{a: 1})
iex> Mnemonix.increment(store, :a, 2)
iex> Mnemonix.get(store, :a)
3

iex> store = Mnemonix.new
iex> Mnemonix.increment(store, :b, 2)
iex> Mnemonix.get(store, :b)
2

iex> store = Mnemonix.new(%{c: "foo"})
iex> Mnemonix.increment(store, :c, 2)
iex> Mnemonix.get(store, :c)
"foo"

iex> store = Mnemonix.new
iex> Mnemonix.increment(store, :d, "foo")
iex> Mnemonix.get(store, :d)
0