Yet Another Currency Parser Generator

A deliberately strict generator which generates regular expressions for matching and parsers for extracting the numeric values from currency strings.

Matching:

Matching English and European currency strings can be matched with the convenience functions like so:

var CP = require('currency-parser')

CP.english_currency_regex.test("$1,234,567.89")     // true
CP.english_currency_regex.test("$-1,234,567.89")    // true
CP.euro_currency_regex.test("\u20ac1.234.567,89")   // true
CP.euro_currency_regex.test("\u20ac(1.234.567,89)") // true
CP.euro_currency_regex.test("(\u00a51.234.567,89)") // true

CP.english_currency_regex.test("$12,34,567.89")    // false
CP.english_currency_regex.test("$-1,234,56789")    // false
CP.euro_currency_regex.test("\u20ac1.2345.67,89")  // false
CP.euro_currency_regex.test("\u20ac(1.234567,89)") // false
CP.euro_currency_regex.test("(\u00a51234.567,89)") // false

The extended (perl style) regular expressions library xregexp is used rather than JavaScript's Regular Expressions to take advantage of the included unicode currency range item (\p{Sc}), and by default, the any of the Unicode currency symbols may appear at the start of the number string.

The English and European style currency regular expressions and parsers refer to the use of decimals and separators, not the currency symbols. Custom expressions can be constructed for arbitrary decimal, separator, and (optionally) currency characters:

var english_currency_regex = CP.currency_regex({decimal:".",separator:","}),
    euro_currency_regex = CP.currency_regex({decimal:",",separator:"."}),
    wierd_currency_regex = CP.currency_regex({decimal:"v",separator:"_"}),

english_currency_regex.test("$-1,234,567.89")     // true
euro_currency_regex.test("\u20ac(1.234.567,89)")  // true
wierd_currency_regex.test("\u20ac(1_234_567v89)") // true

var yen_only_currency_regex = CP.currency_regex({decimal:".",separator:",",symbol:"\u00a5"});
yen_only_currency_regex.test("\u00a5(1,234,567.89)") // true
yen_only_currency_regex.test("$(1,234,567.89)")      // false
yen_only_currency_regex.test("\u20ac(1,234,567.89)") // false

Parsing:

The numeric value of the expression can be extracted via the built in convenience parsers, like so:

CP.english_currency_parser("$1,234,567.89")     // 1234567.89
CP.english_currency_parser("$-1,234,567.89")    // -1234567.89
CP.euro_currency_parser("\u20ac1.234.567,89")   // 1234567.89
CP.euro_currency_parser("\u20ac(1.234.567,89)") // -1234567.89
CP.euro_currency_parser("(\u00a51.234.567,89)") // -1234567.89

var wierd_currency_parser = CP.currency_parser({decimal:"v",separator:"_"});
wierd_currency_parser("$1_234_567v89")        // 1234567.89
wierd_currency_parser("$-1_234_567v89")       // -1234567.89
wierd_currency_parser("\u20ac1_234_567v89")   // 1234567.89
wierd_currency_parser("\u20ac(1_234_567v89)") // -1234567.89
wierd_currency_parser("(\u00a51_234_567v89)") // -1234567.89

var yen_only_currency_regex = CP.currency_regex({decimal:".",separator:",",symbol:"\u00a5"});
yen_only_currency_regex.test("\u20a5(1,234,567.89)") // -1234567.89