Stemmer

https://pub.dev/documentation/stemmer/latest/
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Stemmer is a Dart package that implements stemming algorithms (PorterStemmer and SnowballStemmer) to...
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### Initialize PorterStemmer

Source: https://pub.dev/documentation/stemmer/latest/PorterStemmer/PorterStemmer/PorterStemmer.html

This constructor initializes the stemmer by populating an internal pool with irregular word forms and their corresponding keys. Ensure this setup is complete before using the stemmer for word stemming.

```dart
PorterStemmer() {
  _irregularForms.forEach((String key, List<String> value) {
    value.forEach((String val) {
      _pool[val] = key;
    });
  });
}
```

--------------------------------

### Constructors

Source: https://pub.dev/documentation/stemmer/latest/SnowballStemmer/SnowballStemmer-class.html

Details on how to instantiate the SnowballStemmer class.

```APIDOC
## Constructors

### SnowballStemmer()

Creates a new instance of the SnowballStemmer class.
```

--------------------------------

### Perform stemming with PorterStemmer

Source: https://pub.dev/packages/stemmer

Initializes the PorterStemmer to reduce a word to its base form.

```dart
import 'package:stemmer/stemmer.dart';

PorterStemmer stemmer = PorterStemmer();
stemmer.stem('running'); // outputs: run
```

--------------------------------

### SnowballStemmer Class Overview

Source: https://pub.dev/documentation/stemmer/latest/SnowballStemmer/SnowballStemmer-class.html

Provides an overview of the SnowballStemmer class, its purpose, and the algorithms it implements.

```APIDOC
## SnowballStemmer Class

### Description
A port of the Snowball implementation contained in NLTK. The algorithm for English is documented by Porter (1980). Developed by Martin Porter, these stemmers are named after his programming language, Snowball.

More information is available at http://snowball.tartarus.org/.

A detailed description of the English stemming algorithm can be found under http://snowball.tartarus.org/algorithms/english/stemmer.html.
```

--------------------------------

### PorterStemmer Constructor

Source: https://pub.dev/documentation/stemmer/latest/PorterStemmer/PorterStemmer/PorterStemmer.html

Initializes the PorterStemmer by populating an internal pool with irregular word forms.

```APIDOC
## PorterStemmer()

### Description
Constructs a new PorterStemmer instance. This involves initializing an internal mapping of irregular word forms to their base forms.

### Method
Constructor

### Endpoint
N/A (Class Constructor)

### Parameters
None

### Request Body
None

### Response
N/A (Constructor does not return a value in the typical API sense)

### Implementation Details
The constructor iterates through a predefined map `_irregularForms`. For each entry, it maps each irregular form in the list to its corresponding key (the base form) in an internal pool `_pool`.
```

--------------------------------

### Perform stemming with SnowballStemmer

Source: https://pub.dev/packages/stemmer

Initializes the SnowballStemmer to reduce a word to its base form.

```dart
import 'package:stemmer/stemmer.dart';

SnowballStemmer stemmer = SnowballStemmer();
stemmer.stem('running'); // outputs: run
```

--------------------------------

### Methods

Source: https://pub.dev/documentation/stemmer/latest/SnowballStemmer/SnowballStemmer-class.html

Details on the methods available for the SnowballStemmer class.

```APIDOC
## Methods

### noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

* **Note**: Inherited.

### stem(String origWord, {dynamic toLowerCase = true}) → String

Stems the given word.

* **Parameters**:
    * **origWord** (String) - The word to stem.
    * **toLowerCase** (dynamic) - Whether to convert the word to lowercase before stemming. Defaults to true.

* **Returns**: The stemmed word as a String.

### toString() → String

A string representation of this object.

* **Note**: Inherited.
```

--------------------------------

### SnowballStemmer Constructor

Source: https://pub.dev/documentation/stemmer/latest/SnowballStemmer/SnowballStemmer/SnowballStemmer.html

Initializes a new instance of the SnowballStemmer class.

```APIDOC
## Constructor SnowballStemmer()

### Description
Creates a new instance of the SnowballStemmer class.

### Method
Constructor

### Endpoint
SnowballStemmer.new
```

--------------------------------

### Implement the stem method

Source: https://pub.dev/documentation/stemmer/latest/PorterStemmer/PorterStemmer/stem.html

This function performs the stemming process on a given word, optionally converting it to lowercase first. Words with 2 or fewer characters are returned without modification.

```dart
String stem(String word, {toLowerCase = true}) {
  assert(toLowerCase != null, "toLowerCase cannot be null");

  String stem = toLowerCase ? word.toLowerCase() : word;

  if (_pool.containsKey(word)) {
    return _pool[word]!;
  }

  if (word.length <= 2) {
    // With this line, strings of length 1 or 2 don't go through
    // the stemming process, although no mention is made of this
    // in the published algorithm.
    return stem;
  }

  stem = _step1a(stem);
  stem = _step1b(stem);
  stem = _step1c(stem);
  stem = _step2(stem);
  stem = _step3(stem);
  stem = _step4(stem);
  stem = _step5a(stem);
  stem = _step5b(stem);

  return stem;
}
```

--------------------------------

### Perform case-sensitive stemming

Source: https://pub.dev/packages/stemmer

Demonstrates how to preserve the original casing of the input word during the stemming process.

```dart
import 'package:stemmer/stemmer.dart';

SnowballStemmer stemmer = PorterStemmer();
stemmer.stem('Running'); // outputs: Run
```

--------------------------------

### Stem Method Implementation

Source: https://pub.dev/documentation/stemmer/latest/SnowballStemmer/SnowballStemmer/stem.html

The stem method takes a word and an optional toLowerCase flag, then applies a series of transformations to reduce the word to its root form. It handles special characters, vowel replacements, and multiple stemming steps.

```dart
String stem(String origWord, {toLowerCase = true}) {
  _word = toLowerCase ? origWord.toLowerCase() : origWord;

  // TODO(jeffbailey): Check stopwords
  if (_word.length <= 2) return _word;

  if (_specialWords.containsKey(_word)) return _specialWords[_word]!;

  // Map the different apostrophe characters to a single consistent one
  _word = _word
      .replaceAll('’', ''')
      .replaceAll('‘', ''')
      .replaceAll('‛', ''');

  if (_word.startsWith(''')) _word = _word.substring(1);

  if (_word.startsWith('y')) _word = 'Y' + _word.substring(1);

  // Starts on second letter.
  for (var i = 1; i < _word.length; i++) {
    if (_vowels.contains(_word[i - 1]) && _word[i] == 'y') {
      _word = _word.substring(0, i) + 'Y' + _word.substring(i + 1);
    }
  }

  if (_word.startsWith('gener') || _word.startsWith('commun') || _word.startsWith('arsen')) {
    if (_word.startsWith('gener') || _word.startsWith('arsen')) {
      _r1 = _word.substring(5);
    } else {
      _r1 = _word.substring(6);
    }

    // Starts on second letter.
    for (var i = 1; i < _r1.length; i++) {
      if (!_vowels.contains(_r1[i]) && _vowels.contains(_r1[i - 1])) {
        _r2 = _r1.substring(i + 1);
        break;
      }
    }
  } else {
    _r1r2Standard();
  }

  _step0();
  _step1a();
  _step1b();
  _step1c();
  _step2();
  _step3();
  _step4();
  _step5();

  _word = _word.replaceAll('Y', 'y');

  return _word;
}
```

--------------------------------

### PorterStemmer Class

Source: https://pub.dev/documentation/stemmer/latest/PorterStemmer/PorterStemmer-class.html

Provides functionality for stemming words using the Porter stemming algorithm.

```APIDOC
## PorterStemmer Class

A word stemmer based on the Porter stemming algorithm.

### Constructors

`PorterStemmer()`
    
### Properties

- `hashCode` (int) - The hash code for this object.
- `runtimeType` (Type) - A representation of the runtime type of the object.

### Methods

- `noSuchMethod(Invocation invocation)` (dynamic) - Invoked when a nonexistent method or property is accessed.
- `stem(String word, {dynamic toLowerCase = true})` (String) - Stems `word`. Only stems words that are at least 3 characters, otherwise will return `word`.
- `toString()` (String) - A string representation of this object.

### Operators

- `operator ==(Object other)` (bool) - The equality operator.
```

--------------------------------

### Properties

Source: https://pub.dev/documentation/stemmer/latest/SnowballStemmer/SnowballStemmer-class.html

Information about the properties available on the SnowballStemmer class.

```APIDOC
## Properties

### hashCode → int

The hash code for this object.

* **Note**: No setter, inherited.

### runtimeType → Type

A representation of the runtime type of the object.

* **Note**: No setter, inherited.
```

--------------------------------

### stem method

Source: https://pub.dev/documentation/stemmer/latest/SnowballStemmer/SnowballStemmer/stem.html

The stem method processes an input string to return its stemmed version.

```APIDOC
## Method: stem

### Description
Reduces an input word to its root form based on specific linguistic rules.

### Parameters
- **origWord** (String) - Required - The word to be stemmed.
- **toLowerCase** (dynamic) - Optional - Whether to convert the input word to lowercase before processing. Defaults to true.
```

--------------------------------

### Stem Method

Source: https://pub.dev/documentation/stemmer/latest/PorterStemmer/PorterStemmer/stem.html

The `stem` method takes a word and an optional boolean `toLowerCase` to stem the word. It handles short words by returning them unchanged and applies a series of internal stemming steps.

```APIDOC
## Stem Method

### Description
Stems `word`. Only stems words that are at least 3 characters, otherwise will return `word`. Converts the word to lowercase if `toLowerCase` is true.

### Method
Dart Function

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Parameters
- **word** (String) - Required - The word to be stemmed.
- **toLowerCase** (dynamic) - Optional - Defaults to `true`. If true, the word is converted to lowercase before stemming.

### Request Example
```dart
String result = stem('running', toLowerCase: true);
```

### Response
#### Success Response (200)
- **stemmed_word** (String) - The stemmed version of the input word.

#### Response Example
```json
{
  "stemmed_word": "run"
}
```

## Implementation Details

```dart
String stem(String word, {toLowerCase = true}) {
  assert(toLowerCase != null, "toLowerCase cannot be null");

  String stem = toLowerCase ? word.toLowerCase() : word;

  if (_pool.containsKey(word)) {
    return _pool[word]!;
  }

  if (word.length <= 2) {
    // With this line, strings of length 1 or 2 don't go through
    // the stemming process, although no mention is made of this
    // in the published algorithm.
    return stem;
  }

  stem = _step1a(stem);
  stem = _step1b(stem);
  stem = _step1c(stem);
  stem = _step2(stem);
  stem = _step3(stem);
  stem = _step4(stem);
  stem = _step5a(stem);
  stem = _step5b(stem);

  return stem;
}
```
```

--------------------------------

### SnowballStemmer Class

Source: https://pub.dev/documentation/stemmer/latest/SnowballStemmer

Information about the SnowballStemmer class and its usage.

```APIDOC
## SnowballStemmer

### Description
Provides stemming functionality for linguistic analysis.

### Class
SnowballStemmer

### Usage
```dart
// Example usage (assuming instantiation and method calls are defined elsewhere)
var stemmer = SnowballStemmer();
var stemmedWord = stemmer.stem("running");
print(stemmedWord); // Output will depend on the specific stemmer algorithm
```
```

--------------------------------

### Operators

Source: https://pub.dev/documentation/stemmer/latest/SnowballStemmer/SnowballStemmer-class.html

Information about the operators available for the SnowballStemmer class.

```APIDOC
## Operators

### operator ==(Object other) → bool

The equality operator.

* **Note**: Inherited.
```
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