protocol

n_grams_protocol

N-gram generation and counting protocol.

Availability:
logtalk_load(n_grams(loader))
Author: Paulo Moura
Version: 1:0:0
Date: 2026-09-05
Compilation flags:
static
Dependencies:
(none)
Remarks:
(none)
Inherited public predicates:
(none)

Public predicates

n_grams/3

Generates overlapping n-grams from a list of text tokens.

Compilation flags:
static
Template:
n_grams(N,Tokens,NGrams)
Mode and number of proofs:
n_grams(+positive_integer,+list(text),-list(list(text))) - one_or_error
Exceptions:
The Representation parameter is a variable:
instantiation_error
The Representation parameter neither a variable nor atom, chars, or codes:
domain_error(text_representation,Representation)
N is a variable:
instantiation_error
N is neither a variable nor a positive integer:
type_error(positive_integer,Options)
Tokens is a partial list or a list with an element Element which is not ground:
instantiation_error
The Representation parameter is atom but a ground element Element of the list Tokens is not an atom:
type_error(atom,Element)
The Representation parameter is chars but an element Element of the list Tokens is not a list of characters:
type_error(chars,Element)
The Representation parameter is codes but an element Element of the list Tokens is not a list of character codes:
type_error(codes,Element)

n_grams/4

Generates n-grams from a list of text tokens using the given options.

Compilation flags:
static
Template:
n_grams(N,Tokens,NGrams,Options)
Mode and number of proofs:
n_grams(+positive_integer,+list(text),-list(list(text)),+list(compound)) - one_or_error
Exceptions:
The Representation parameter is a variable:
instantiation_error
The Representation parameter neither a variable nor atom, chars, or codes:
domain_error(text_representation,Representation)
N is a variable:
instantiation_error
N is neither a variable nor a positive integer:
type_error(positive_integer,Options)
Tokens is a partial list or a list with an element Element which is not ground:
instantiation_error
The Representation parameter is atom but a ground element Element of the list Tokens is not an atom:
type_error(atom,Element)
The Representation parameter is chars but an element Element of the list Tokens is not a list of characters:
type_error(chars,Element)
The Representation parameter is codes but an element Element of the list Tokens is not a list of character codes:
type_error(codes,Element)
Options is a variable:
instantiation_error
Options is neither a variable nor a list:
type_error(list,Options)
An element Option of the list Options is a variable:
instantiation_error
An element Option of the list Options is neither a variable nor a compound term:
type_error(compound,Option)
An element Option of the list Options is a compound term but not a valid option:
domain_error(option,Option)

character_n_grams/3

Generates overlapping character n-grams from a text value.

Compilation flags:
static
Template:
character_n_grams(N,Text,NGrams)
Mode and number of proofs:
character_n_grams(+positive_integer,+text,-list(text)) - one_or_error
Exceptions:
The Representation parameter is a variable:
instantiation_error
The Representation parameter neither a variable nor atom, chars, or codes:
domain_error(text_representation,Representation)
N is a variable:
instantiation_error
N is neither a variable nor a positive integer:
type_error(positive_integer,Options)
Text is not ground:
instantiation_error
The Representation parameter is atom but Text is not an atom:
type_error(atom,Text)
The Representation parameter is chars but Text is not a list of characters:
type_error(chars,Text)
The Representation parameter is codes but Text is not a list of character codes:
type_error(codes,Text)

character_n_grams/4

Generates character n-grams from a text value using the given options.

Compilation flags:
static
Template:
character_n_grams(N,Text,NGrams,Options)
Mode and number of proofs:
character_n_grams(+positive_integer,+text,-list(text),+list(compound)) - one_or_error
Exceptions:
The Representation parameter is a variable:
instantiation_error
The Representation parameter neither a variable nor atom, chars, or codes:
domain_error(text_representation,Representation)
N is a variable:
instantiation_error
N is neither a variable nor a positive integer:
type_error(positive_integer,Options)
Text is not ground:
instantiation_error
The Representation parameter is atom but Text is not an atom:
type_error(atom,Text)
The Representation parameter is chars but Text is not a list of characters:
type_error(chars,Text)
The Representation parameter is codes but Text is not a list of character codes:
type_error(codes,Text)
Options is a variable:
instantiation_error
Options is neither a variable nor a list:
type_error(list,Options)
An element Option of the list Options is a variable:
instantiation_error
An element Option of the list Options is neither a variable nor a compound term:
type_error(compound,Option)
An element Option of the list Options is a compound term but not a valid option:
domain_error(option,Option)

count/2

Counts n-gram occurrences, preserving the order of first occurrence. Assumes NGrams is valid.

Compilation flags:
static
Template:
count(NGrams,Counts)
Mode and number of proofs:
count(+list(text),-list(pair(text,positive_integer))) - one
count(+list(list(text)),-list(pair(list(text),positive_integer))) - one

count/3

Counts n-gram occurrences using the requested ordering. Valid orderings are first_occurrence, standard, and frequency_descending. Assumes NGrams is valid.

Compilation flags:
static
Template:
count(Order,NGrams,Counts)
Mode and number of proofs:
count(+atom,+list(text),-list(pair(text,positive_integer))) - one_or_error
count(+atom,+list(list(text)),-list(pair(list(text),positive_integer))) - one_or_error
Exceptions:
Order is a variable:
instantiation_error
Order is neither a variable nor a valid ordering:
domain_error(count_order,Order)

bigrams/2

Generates overlapping bigrams from a list of text tokens.

Compilation flags:
static
Template:
bigrams(Tokens,Bigrams)
Mode and number of proofs:
bigrams(+list(text),-list(list(text))) - one_or_error
Exceptions:
The Representation parameter is a variable:
instantiation_error
The Representation parameter neither a variable nor atom, chars, or codes:
domain_error(text_representation,Representation)
Tokens is a partial list or a list with an element Element which is not ground:
instantiation_error
The Representation parameter is atom but a ground element Element of the list Tokens is not an atom:
type_error(atom,Element)
The Representation parameter is chars but an element Element of the list Tokens is not a list of characters:
type_error(chars,Element)
The Representation parameter is codes but an element Element of the list Tokens is not a list of character codes:
type_error(codes,Element)

trigrams/2

Generates overlapping trigrams from a list of text tokens.

Compilation flags:
static
Template:
trigrams(Tokens,Trigrams)
Mode and number of proofs:
trigrams(+list(text),-list(list(text))) - one_or_error
Exceptions:
The Representation parameter is a variable:
instantiation_error
The Representation parameter neither a variable nor atom, chars, or codes:
domain_error(text_representation,Representation)
Tokens is a partial list or a list with an element Element which is not ground:
instantiation_error
The Representation parameter is atom but a ground element Element of the list Tokens is not an atom:
type_error(atom,Element)
The Representation parameter is chars but an element Element of the list Tokens is not a list of characters:
type_error(chars,Element)
The Representation parameter is codes but an element Element of the list Tokens is not a list of character codes:
type_error(codes,Element)

Protected predicates

(none)

Private predicates

(none)

Operators

(none)

See also

n_grams(Representation)