Optional helpers for converting Longbridge wire-format strings to numeric values.
Longbridge returns monetary and quantitative fields as strings
(e.g. "0.0723", "3241500000000"). This module provides
helpers to convert those strings to a numeric type without
pulling in the :decimal package as a hard dependency.
Most callers will want to use Decimal from the :decimal
package for exact arithmetic on monetary values. If you don't
depend on :decimal, parse_number/1 returns either an
integer or a float depending on whether the string contains
a decimal point.
Usage with :decimal
{:ok, config} = Longbridge.OAuth.load_token(client_id)
{:ok, %{price_close: p}} = Longbridge.FundamentalContext.valuation_comparison(config, "AAPL.US", "USD")
dec = Longbridge.Decimal.to_bigdecimal(p)
Float.round(Decimal.to_float(dec), 2)Usage without :decimal
price = Longbridge.Decimal.parse_number("0.0723")
# => 0.0723To use the :decimal-backed helpers, add {:decimal, "~> 2.0 or ~> 3.0"}
to your mix.exs dependencies.
Summary
Functions
Parses a wire-format numeric string.
Returns an integer if the string contains no decimal point, or
a float otherwise. Returns nil for empty strings or nil.
Examples
iex> Longbridge.Decimal.parse_number("100")
100
iex> Longbridge.Decimal.parse_number("3.14")
3.14
iex> Longbridge.Decimal.parse_number("")
nilSums a list of wire-format numeric strings into a single
Decimal. nil and empty strings are treated as zero.
Requires the :decimal package in your app.
Parses a wire-format numeric string as a Decimal.
Requires the :decimal package as a dependency in your app.
Returns nil for empty/nil inputs.
If :decimal is not loaded, raises ArgumentError at call time
with a hint to add the dependency.
Examples
iex> Longbridge.Decimal.to_bigdecimal("3.14") |> Decimal.to_string()
"3.14"