Forex.Support (Forex v1.1.2)

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The Forex.Support module provides helper functions, for example, for formatting the exchange rates values.

Summary

Functions

atomize_code(code)

Conver the binary currency code to an existing atom representation.

format_value(value, format)

Format the rate value based on the format option

map_date(date)

Map the date to a Date struct or nil if the date cannot be parsed.

parse_date(string)

Attempt to parse a date from a binary string in ISO 8601 format

round_value(value, precision)

Round the rate value based on the round option

stringify_code(code)

Convert the currency code to a default string representation (uppercase string).

Functions

atomize_code(code)

@spec atomize_code(atom() | String.t()) :: atom()

Conver the binary currency code to an existing atom representation.

Examples

  iex> Forex.Support.atomize_code("usd")
  :usd

  iex> Forex.Support.atomize_code(:usd)
  :usd

  iex> Forex.Support.atomize_code("USD")
  :usd

  iex> Forex.Support.atomize_code(:USD)
  :usd

  iex> Forex.Support.atomize_code("uSD")
  :usd

  iex> Forex.Support.atomize_code(1)
  ** (FunctionClauseError) no function clause matching in Forex.Support.atomize_code/1

format_value(value, format)

@spec format_value(number() | binary() | Decimal.t(), :string | :decimal) ::
  formatted_value :: binary() | Decimal.t()

Format the rate value based on the format option

Examples

iex> Forex.Support.format_value("1.2345", :string)
"1.2345"

iex> Forex.Support.format_value("1.2345", :decimal)
Decimal.new("1.2345")

iex> Forex.Support.format_value("1.2345", :decimal)
Decimal.new("1.2345")

iex> Forex.Support.format_value("1.2345", :string)
"1.2345"

iex> Forex.Support.format_value(1.2345, :decimal)
Decimal.new("1.2345")

iex> Forex.Support.format_value(1.2345, :string)
"1.2345"

iex> Forex.Support.format_value(Decimal.new("1.2345"), :decimal)
Decimal.new("1.2345")

iex> Forex.Support.format_value(Decimal.new("1.2345"), :string)
"1.2345"

iex> Forex.Support.format_value(1.2345, :number)
** (Forex.FormatError) Invalid format value: number

map_date(date)

@spec map_date(parsable_date()) :: Date.t() | nil

Map the date to a Date struct or nil if the date cannot be parsed.

Examples

iex> Forex.Support.map_date("2020-01-01")
~D[2020-01-01]

iex> Forex.Support.map_date("2020-01-01T00:00:00Z")
~D[2020-01-01]

iex> Forex.Support.map_date({1982, 2, 25})
~D[1982-02-25]

iex> Forex.Support.map_date(~D[2020-01-01])
~D[2020-01-01]

iex> Forex.Support.map_date(~U[2020-01-01T00:00:00Z])
~D[2020-01-01]

iex> Forex.Support.map_date("2020-01-01T00:00:00")
nil

iex> Forex.Support.map_date("1982-02-31T00:00:00Z")
nil

iex> Forex.Support.map_date(1982)
nil

parse_date(string)

@spec parse_date(parsable_date()) :: {:ok, Date.t()} | {:error, :invalid_date}

Attempt to parse a date from a binary string in ISO 8601 format

Examples

iex> Forex.Support.parse_date("2020-01-01")
{:ok, ~D[2020-01-01]}

iex> Forex.Support.parse_date("2020-01-01T00:00:00Z")
{:ok, ~D[2020-01-01]}

iex> Forex.Support.parse_date({1982, 2, 25})
{:ok, ~D[1982-02-25]}

iex> Forex.Support.parse_date(~D[2020-01-01])
{:ok, ~D[2020-01-01]}

iex> Forex.Support.parse_date(~U[2020-01-01T00:00:00Z])
{:ok, ~D[2020-01-01]}

iex> Forex.Support.parse_date("2020-01-01T00:00:00")
{:error, :invalid_date}

iex> Forex.Support.parse_date("1982-02-31T00:00:00Z")
{:error, :invalid_date}

iex> Forex.Support.parse_date(1982)
{:error, :invalid_date}

round_value(value, precision)

@spec round_value(any(), integer() | nil) :: any()

Round the rate value based on the round option

Examples

  iex> Forex.Support.round_value(1.2345, 2)
  1.23

  iex> Forex.Support.round_value(1.2345, 4)
  1.2345

  iex> Forex.Support.round_value(1.2345, 0)
  1.0

  iex> Forex.Support.round_value(1.2345, 15)
  1.2345

  iex> Forex.Support.round_value(Decimal.new("1.2345"), 2)
  Decimal.new("1.23")

  iex> Forex.Support.round_value(Decimal.new("1.2345"), 4)
  Decimal.new("1.2345")

  iex> Forex.Support.round_value(Decimal.new("1.2345"), 0)
  Decimal.new("1")

  iex> Forex.Support.round_value("1.2345", 2)
  "1.23"

  iex> Forex.Support.round_value("1.2345", 4)
  "1.2345"

  iex> Forex.Support.round_value("1.2345", nil)
  "1.2345"

  iex> Forex.Support.round_value(nil, 2)
  nil

  iex> Forex.Support.round_value(1.2345, 16)
  ** (FunctionClauseError) no function clause matching in Forex.Support.round_value/2

stringify_code(code)

@spec stringify_code(atom() | String.t()) :: String.t()

Convert the currency code to a default string representation (uppercase string).

Examples

iex> Forex.Support.stringify_code(:usd)
"USD"

iex> Forex.Support.stringify_code("usd")
"USD"

iex> Forex.Support.stringify_code("USD")
"USD"

iex> Forex.Support.stringify_code(:USD)
"USD"

iex> Forex.Support.stringify_code(:usd)
"USD"

iex> Forex.Support.stringify_code("usd")
"USD"

iex> Forex.Support.stringify_code("USD")
"USD"

iex> Forex.Support.stringify_code(:USD)
"USD"

iex> Forex.Support.stringify_code(1)
** (FunctionClauseError) no function clause matching in Forex.Support.stringify_code/1