Collate is a simple collation library for comparing strings in various languages for Go. It's designed for the BuntDB project, and is simliar to the collation that is found in traditional database systems

The idea is that you call a function with a collation name and it generates a Less(a, b string) bool function that can be used for sorting using the sort package or with B-Tree style databases.

go get -u github.com/tidwall/collate

// create a case-insensitive collation for spanish.
less := collate.IndexString("SPANISH_CI")
println(less("Hola", "hola"))
println(less("hola", "Hola"))
// Output:
// false
// false

Add _CI to the collation name to specify case-insensitive comparing.
Add _CS for case-sensitive compares, this is the default.

collate.Index("SPANISH_CI") // Case-insensitive collation for spanish
collate.Index("SPANISH_CS") // Case-sensitive collation for spanish

Add _LOOSE to ignores diacritics, case and weight.

Add _NUM to specifies that numbers should sort numerically ("2" < "12")

You can also compare fields in json documents using the IndexJSON function. The GJSON is used under-the-hood.

var jsonA = `{"name":{"last":"Miller"}}`
var jsonB = `{"name":{"last":"anderson"}}`
less := collate.IndexJSON("ENGLISH_CI", "name.last")
println(less(jsonA, jsonB))
println(less(jsonB, jsonA))
// Output:
// false
// true

Afrikaans Albanian AmericanEnglish Amharic Arabic Armenian Azerbaijani Bengali BrazilianPortuguese BritishEnglish Bulgarian Burmese CanadianFrench Catalan Chinese Croatian Czech Danish Dutch English Estonian EuropeanPortuguese EuropeanSpanish Filipino Finnish French Georgian German Greek Gujarati Hebrew Hindi Hungarian Icelandic Indonesian Italian Japanese Kannada Kazakh Khmer Kirghiz Korean Lao LatinAmericanSpanish Latvian Lithuanian Macedonian Malay Malayalam Marathi ModernStandardArabic Mongolian Nepali Norwegian Persian Polish Portuguese Punjabi Romanian Russian Serbian SerbianLatin SimplifiedChinese Sinhala Slovak Slovenian Spanish Swahili Swedish Tamil Telugu Thai TraditionalChinese Turkish Ukrainian Urdu Uzbek Vietnamese Zulu

Josh Baker @tidwall

Collate source code is available under the MIT License.