# View Source Cldr.Number.Parser(Cldr Numbers v2.27.0)

Functions for parsing numbers and currencies from a string.

# Link to this section Summary

## Functions

Find a substring at the beginning and/or end of a string, and replace it.

Parse a string in a locale-aware manner and return a number.

Removes any whitespace strings from between tokens in a list.

Maps a list of terms (usually strings and atoms) calling a resolver function that operates on each binary term.

Resolve curencies from strings within a list.

Resolve a currency from the beginning and/or the end of a string

Resolve and tokenize percent or permille from the beginning and/or the end of a string

Resolve and tokenize percent and permille sybols from strings within a list.

Scans a string in a locale-aware manner and returns a list of strings and numbers.

# per()

View Source

## Specs

`per() :: :percent | :permille`

# find_and_replace(string_map, string, fuzzy \\ nil)

View Source (since 2.22.0)

## Specs

```find_and_replace(%{required(binary()) => term()}, binary(), float() | nil) ::
{:ok, list()} | {:error, {module(), binary()}}```

Find a substring at the beginning and/or end of a string, and replace it.

Ignore any whitespace found at the start or end of the string when looking for a match. A match is considered only if there is no alphabetic character adjacent to the match.

When multiple matches are found, the longest match is replaced.

## arguments Arguments

• `string_map` is a map where the keys are the strings to be matched and the values are the replacement.

• `string` is the string in which the find and replace operation takes place.

• `fuzzy` is floating point number between 0.0 and 1.0 that is used to implement a fuzzy match using `String.jaro_distance/2`. The default is `nil` which means the match is exact at the beginning and/or the end of the `string`.

## returns Returns

• `{:ok, list}` where list is `string` broken into the replacement(s) and the remainder after find and replace. Or

• `{:error, {exception, reason}}` will be returned if the `fuzzy` parameter is invalid or if no search was found and no replacement made. In the later case, `exception` will be `Cldr.Number.ParseError`.

## examples Examples

``````iex> Cldr.Number.Parser.find_and_replace(%{"this" => "that"}, "This is a string")
{:ok, ["that", " is a string"]}

iex> Cldr.Number.Parser.find_and_replace(%{"string" => "term"}, "This is a string")
{:ok, ["This is a ", "term"]}

iex> Cldr.Number.Parser.find_and_replace(%{"string" => "term", "this" => "that"}, "This is a string")
{:ok, ["that", " is a ", "term"]}

iex> Cldr.Number.Parser.find_and_replace(%{"unknown" => "term"}, "This is a string")
{:error, {Cldr.Number.ParseError, "No match was found"}}``````

# parse(string, options \\ [])

View Source

## Specs

```parse(String.t(), Keyword.t()) ::
{:ok, integer() | float() | Decimal.t()} | {:error, {module(), String.t()}}```

Parse a string in a locale-aware manner and return a number.

## arguments Arguments

• `string` is any `t:String`

• `options` is a keyword list of options

## options Options

• `:number` is one of `:integer`, `:float`, `:decimal` or `nil`. The default is `nil` meaning that the type auto-detected as either an `integer` or a `float`.

• `:backend` is any module that includes `use Cldr` and is therefore a CLDR backend module. The default is `Cldr.default_backend/0`.

• `:locale` is any locale returned by `Cldr.known_locale_names/1` or a `Cldr.LanguageTag.t`. The default is `options[:backend].get_locale/1`.

## returns Returns

• A number of the requested or default type or

• `{:error, {exception, message}}` if no number could be determined

## notes Notes

This function parses a string to return a number but in a locale-aware manner. It will normalise digits, grouping characters and decimal separators.

It will transliterate digits that are in the number system of the specific locale. For example, if the locale is `th` (Thailand), then Thai digits are transliterated to the Latin script before parsing.

Some number systems do not have decimal digits and in this case an error will be returned, rather than continue parsing and return misleading results.

It also caters for different forms of the `+` and `-` symbols that appear in Unicode and strips any `_` characters that might be used for formatting in a string.

It then parses the number using the Elixir standard library functions.

If the option `:number` is used and the parsed number cannot be coerced to this type without losing precision then an error is returned.

## examples Examples

``````iex> Cldr.Number.Parser.parse("＋1.000,34", locale: "de")
{:ok, 1000.34}

iex> Cldr.Number.Parser.parse("-1_000_000.34")
{:ok, -1000000.34}

iex> Cldr.Number.Parser.parse("1.000", locale: "de", number: :integer)
{:ok, 1000}

iex> Cldr.Number.Parser.parse "١٢٣٤٥", locale: "ar"
{:ok, 12345}

# 1_000.34 cannot be coerced into an integer
# without precision loss so an error is returned.
iex> Cldr.Number.Parser.parse("＋1.000,34", locale: "de", number: :integer)
{:error,
{Cldr.Number.ParseError,
"The string \"＋1.000,34\" could not be parsed as a number"}}

iex> Cldr.Number.Parser.parse "一万二千三百四十五", locale: "ja-u-nu-jpan"
{:error,
{Cldr.UnknownNumberSystemError,
"The number system :jpan is not known or does not have digits"}}``````

# remove_whitespace_between_tokens(first)

View Source

Removes any whitespace strings from between tokens in a list.

Tokens are numbers or atoms.

# resolve(list, resolver, options)

View Source

## Specs

`resolve([any()], (... -> any()), Keyword.t()) :: list()`

Maps a list of terms (usually strings and atoms) calling a resolver function that operates on each binary term.

If the resolver function returns `{:error, term}` then no change is made to the term, otherwise the return value of the resolver replaces the original term.

## arguments Arguments

• `list` is a list of terms. Typically this is the result of calling `Cldr.Number.Parser.scan/1`.

• `resolver` is a function that takes two arguments. The first is one of the terms in the `list`. The second is `options`.

• `options` is a keyword list of options that is passed to the resolver function.

## note Note

• The resolver is called only on binary elements of the list.

## returns Returns

• `list` as modified through the application of the resolver function on each binary term.

## examples Examples

See `Cldr.Number.Parser.resolve_currencies/2` and `Cldr.Number.Parser.resolve_pers/2` which both use this function.

# resolve_currencies(list, options \\ [])

View Source

## Specs

```resolve_currencies([String.t(), ...], Keyword.t()) :: [
Cldr.Currency.code() | String.t()
]```

Resolve curencies from strings within a list.

Currencies can be identified at the beginning and/or the end of a string.

## arguments Arguments

• `list` is any list in which currency names and symbols are expected

• `options` is a keyword list of options

## options Options

• `:backend` is any module() that includes `use Cldr` and therefore is a `Cldr` backend module(). The default is `Cldr.default_backend!/0`

• `:locale` is any valid locale returned by `Cldr.known_locale_names/1` or a `t:Cldr.LanguageTag` struct returned by `Cldr.Locale.new!/2` The default is `options[:backend].get_locale()`

• `:only` is an `atom` or list of `atoms` representing the currencies or currency types to be considered for a match. The equates to a list of acceptable currencies for parsing. See the notes below for currency types.

• `:except` is an `atom` or list of `atoms` representing the currencies or currency types to be not considered for a match. This equates to a list of unacceptable currencies for parsing. See the notes below for currency types.

• `:fuzzy` is a float greater than `0.0` and less than or equal to `1.0` which is used as input to `String.jaro_distance/2` to determine is the provided currency string is close enough to a known currency string for it to identify definitively a currency code. It is recommended to use numbers greater than `0.8` in order to reduce false positives.

## returns Returns

• An ISO4217 currency code as an atom or

• `{:error, {exception, message}}`

## notes Notes

The `:only` and `:except` options accept a list of currency codes and/or currency types. The following types are recognised.

If both `:only` and `:except` are specified, the `:except` entries take priority - that means any entries in `:except` are removed from the `:only` entries.

• `:all`, the default, considers all currencies

• `:current` considers those currencies that have a `:to` date of nil and which also is a known ISO4217 currency

• `:historic` is the opposite of `:current`

• `:tender` considers currencies that are legal tender

• `:unannotated` considers currencies that don't have "(some string)" in their names. These are usually financial instruments.

## examples Examples

``````iex> Cldr.Number.Parser.scan("100 US dollars")
...> |> Cldr.Number.Parser.resolve_currencies
[100, :USD]

iex> Cldr.Number.Parser.scan("100 eurosports")
...> |> Cldr.Number.Parser.resolve_currencies(fuzzy: 0.8)
[100, :EUR]

iex> Cldr.Number.Parser.scan("100 dollars des États-Unis")
...> |> Cldr.Number.Parser.resolve_currencies(locale: "fr")
[100, :USD]``````

# resolve_currency(string, options \\ [])

View Source

## Specs

```resolve_currency(String.t(), Keyword.t()) ::
Cldr.Currency.code()
| [Cldr.Currency.code() | String.t()]
| {:error, {module(), String.t()}}```

Resolve a currency from the beginning and/or the end of a string

## arguments Arguments

• `list` is any list in which currency names and symbols are expected

• `options` is a keyword list of options

## options Options

• `:backend` is any module() that includes `use Cldr` and therefore is a `Cldr` backend module(). The default is `Cldr.default_backend!/0`

• `:locale` is any valid locale returned by `Cldr.known_locale_names/1` or a `Cldr.LanguageTag` struct returned by `Cldr.Locale.new!/2` The default is `options[:backend].get_locale()`

• `:only` is an `atom` or list of `atoms` representing the currencies or currency types to be considered for a match. The equates to a list of acceptable currencies for parsing. See the notes below for currency types.

• `:except` is an `atom` or list of `atoms` representing the currencies or currency types to be not considered for a match. This equates to a list of unacceptable currencies for parsing. See the notes below for currency types.

• `:fuzzy` is a float greater than `0.0` and less than or equal to `1.0` which is used as input to `String.jaro_distance/2` to determine is the provided currency string is close enough to a known currency string for it to identify definitively a currency code. It is recommended to use numbers greater than `0.8` in order to reduce false positives.

## returns Returns

• An ISO417 currency code as an atom or

• `{:error, {exception, message}}`

## notes Notes

The `:only` and `:except` options accept a list of currency codes and/or currency types. The following types are recognised.

If both `:only` and `:except` are specified, the `:except` entries take priority - that means any entries in `:except` are removed from the `:only` entries.

• `:all`, the default, considers all currencies

• `:current` considers those currencies that have a `:to` date of nil and which also is a known ISO4217 currency

• `:historic` is the opposite of `:current`

• `:tender` considers currencies that are legal tender

• `:unannotated` considers currencies that don't have "(some string)" in their names. These are usually financial instruments.

## examples Examples

``````iex> Cldr.Number.Parser.resolve_currency("US dollars")
[:USD]

iex> Cldr.Number.Parser.resolve_currency("100 eurosports", fuzzy: 0.75)
[:EUR]

iex> Cldr.Number.Parser.resolve_currency("dollars des États-Unis", locale: "fr")
[:USD]

iex> Cldr.Number.Parser.resolve_currency("not a known currency", locale: "fr")
{:error,
{Cldr.UnknownCurrencyError,
"The currency \"not a known currency\" is unknown or not supported"}}``````

# resolve_per(string, options \\ [])

View Source (since 2.21.0)

## Specs

```resolve_per(String.t(), Keyword.t()) ::
per() | [per() | String.t()] | {:error, {module(), String.t()}}```

Resolve and tokenize percent or permille from the beginning and/or the end of a string

## arguments Arguments

• `list` is any list in which percent and permille symbols are expected

• `options` is a keyword list of options

## returns Returns

• An `:percent` or `permille` or

• `{:error, {exception, message}}`

## examples Examples

``````iex> Cldr.Number.Parser.resolve_per "11%"
["11", :percent]

iex> Cldr.Number.Parser.resolve_per "% of linguists"
[:percent, " of linguists"]

iex> Cldr.Number.Parser.resolve_per "% of linguists %"
[:percent, " of linguists ", :percent]``````

# resolve_pers(list, options \\ [])

View Source (since 2.21.0)

## Specs

`resolve_pers([String.t(), ...], Keyword.t()) :: [per() | String.t()]`

Resolve and tokenize percent and permille sybols from strings within a list.

Percent and permille symbols can be identified at the beginning and/or the end of a string.

## arguments Arguments

• `list` is any list in which percent and permille symbols are expected

• `options` is a keyword list of options

## examples Examples

``````iex> Cldr.Number.Parser.scan("100%")
...> |> Cldr.Number.Parser.resolve_pers()
[100, :percent]``````

# scan(string, options \\ [])

View Source

## Specs

```scan(String.t(), Keyword.t()) ::
[String.t() | integer() | float() | Decimal.t()]
| {:error, {module(), String.t()}}```

Scans a string in a locale-aware manner and returns a list of strings and numbers.

## arguments Arguments

• `string` is any `String.t`

• `options` is a keyword list of options

## options Options

• `:number` is one of `:integer`, `:float`, `:decimal` or `nil`. The default is `nil` meaning that the type auto-detected as either an `integer` or a `float`.

• `:backend` is any module that includes `use Cldr` and is therefore a CLDR backend module. The default is `Cldr.default_backend!/0`.

• `:locale` is any locale returned by `Cldr.known_locale_names/1` or a `t:Cldr.LanguageTag`. The default is `options[:backend].get_locale/1`.

## returns Returns

• A list of strings and numbers

## notes Notes

Number parsing is performed by `Cldr.Number.Parser.parse/2` and any options provided are passed to that function.

## examples Examples

``````iex> Cldr.Number.Parser.scan("£1_000_000.34")
["£", 1000000.34]

iex> Cldr.Number.Parser.scan("I want £1_000_000 dollars")
["I want £", 1000000, " dollars"]

iex> Cldr.Number.Parser.scan("The prize is 23")
["The prize is ", 23]

iex> Cldr.Number.Parser.scan("The lottery number is 23 for the next draw")
["The lottery number is ", 23, " for the next draw"]

iex> Cldr.Number.Parser.scan("The loss is -1.000 euros", locale: "de", number: :integer)
["The loss is ", -1000, " euros"]

iex> Cldr.Number.Parser.scan "1kg"
[1, "kg"]

iex> Cldr.Number.Parser.scan "A number is the arab script ١٢٣٤٥", locale: "ar"
["A number is the arab script ", 12345]``````