Yesterday is but today's memory, and tomorrow is today's dream.

Gibran is an Elixir natural language processor. Lofty goals for Gibran include:

• Metaphone phonetic coding system
• Soundex algorithm
• Porter Stemming algorithm
• String similarity as described by Simon White

Currently, Gibran ships with the following features:

• Token count, unique token count, and character count
• Average characters per token
• HashDicts of tokens and their frequencies, lengths, and densities
• The longest token(s) and its length
• The most frequent token(s) and its frequency
• Unique tokens
• Levenshtein distance algorithm

Let's start with something simple.

alias Gibran.Tokeniser
alias Gibran.Counter

str = "Yesterday is but today's memory, and tomorrow is today's dream."
Tokeniser.tokenise(str)
# => ["yesterday", "is", "but", "today's", "memory", "and", "tomorrow", "is", "today's", "dream"]

Tokeniser.tokenise(str) |> Counter.uniq_token_count
# => 8

By default Gibran uses the following regular expression to tokenise strings: ~r/[^\p{L}'-]/u. You can provide your own regular expression through the pattern option. You can combine pattern with exclude to create sophisticated tokenisation strategies.

Tokeniser.tokenise(string, exclude: &String.length(&1) < 4) |> Counter.token_count
# => 6

The exclude option accepts a string, a function, a regular expression, or a list combining any one or more of those types.

# Using `exclude` with a function.
Tokeniser.tokenise("Kingdom of the Imagination", exclude: &(String.length(&1) < 10))
["imagination"]

# Using `exclude` with a regular expression.
Tokeniser.tokenise("Sand and Foam", exclude: ~r/and/)
["foam"]

# Using `exclude` with a string.
Tokeniser.tokenise("Eye of The Prophet", exclude: "eye of")
["the", "prophet"]

# Using `exclude` with a list of a combination of types.
Tokeniser.tokenise("Eye of The Prophet", exclude: ["eye", &(String.ends_with?(&1, "he")), ~r/of/])
["prophet"]

Gibran provides a shortcut for working with strings directly (instead of running them through the tokeniser first).

Gibran.from_string(str, :token_count, opts: [exclude: &String.length(&1) < 4])
# => 6

To avoid inconsistencies that arise from character-casing, Gibran normalises input before applying transformations.

Ordinary use:

iex(1)> Gibran.Levenshtein.distance("kitten", "sitting")
3

The Levenshtein distance for the same string is 0.

iex(2)> Gibran.Levenshtein.distance("snail", "snail")
0

The Levenshtein distance is case-sensitive.

iex(3)> Gibran.Levenshtein.distance("HOUSEBOAT", "houseboat")
9

The function can accept charlists as well as strings.

 iex(4)> Gibran.Levenshtein.distance('jogging', 'logger')
 4

The doctests contain extensive usage examples. Please take a look there for more details.