23 classes are annotated with SearchApiProcessor in Search API 8

AddHierarchy in src/Plugin/search_api/processor/AddHierarchy.php

Adds all ancestors' IDs to a hierarchical field.

AddURL in src/Plugin/search_api/processor/AddURL.php

Adds the item's URL to the indexed data.

AggregatedFields in src/Plugin/search_api/processor/AggregatedFields.php

Adds customized aggregations of existing fields to the index.

ContentAccess in src/Plugin/search_api/processor/ContentAccess.php

Adds content access checks for nodes and comments.

EntityStatus in src/Plugin/search_api/processor/EntityStatus.php

Excludes unpublished nodes from node indexes.

Highlight in src/Plugin/search_api/processor/Highlight.php

Adds a highlighted excerpt to results and highlights returned fields.

HtmlFilter in src/Plugin/search_api/processor/HtmlFilter.php

Strips HTML tags from fulltext fields and decodes HTML entities.

IgnoreCase in src/Plugin/search_api/processor/IgnoreCase.php

Makes searches case-insensitive on selected fields.

IgnoreCharacters in src/Plugin/search_api/processor/IgnoreCharacters.php

Configure types of characters which should be ignored for searches.

LanguageWithFallback in src/Plugin/search_api/processor/LanguageWithFallback.php

Adds the item's language (with fallbacks) to the indexed data.

NoUi in tests/search_api_test_no_ui/src/Plugin/search_api/processor/NoUi.php

Provides a test processor that should be hidden from the UI.

NumberFieldBoost in src/Plugin/search_api/processor/NumberFieldBoost.php

Adds a boost based on a number field value.

RenderedItem in src/Plugin/search_api/processor/RenderedItem.php

Adds an additional field containing the rendered item.

ReverseEntityReferences in src/Plugin/search_api/processor/ReverseEntityReferences.php

Allows indexing of reverse entity references.

RoleAccess in src/Plugin/search_api/processor/RoleAccess.php

Adds access checks based on user roles.

RoleFilter in src/Plugin/search_api/processor/RoleFilter.php

Filters out users based on their role.

SoulMate in tests/search_api_test_extraction/src/Plugin/search_api/processor/SoulMate.php

Adds the user's soul mate node for indexing.

Stemmer in src/Plugin/search_api/processor/Stemmer.php

Stems search terms.

Stopwords in src/Plugin/search_api/processor/Stopwords.php

Allows you to define stopwords which will be ignored in searches.

TestProcessor in tests/search_api_test/src/Plugin/search_api/processor/TestProcessor.php

Provides a processor with dependencies, for the dependency removal tests.

Tokenizer in src/Plugin/search_api/processor/Tokenizer.php

Splits text into individual words for searching.

Transliteration in src/Plugin/search_api/processor/Transliteration.php

Makes searches insensitive to accents and other non-ASCII characters.

TypeBoost in src/Plugin/search_api/processor/TypeBoost.php

Adds a boost to indexed items based on their datasource and/or bundle.