Irish analyzer

The built-in irish analyzer can be applied to a text field using the following command:

  1. PUT /irish-index
  2. {
  3.   "mappings": {
  4.     "properties": {
  5.       "content": {
  6.         "type": "text",
  7.         "analyzer": "irish"
  8.       }
  9.     }
  10.   }
  11. }

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Stem exclusion

You can use stem_exclusion with this language analyzer using the following command:

  1. PUT index_with_stem_exclusion_irish_analyzer
  2. {
  3.   "settings": {
  4.     "analysis": {
  5.       "analyzer": {
  6.         "stem_exclusion_irish_analyzer": {
  7.           "type": "irish",
  8.           "stem_exclusion": ["údarás", "faomhadh"]
  9.         }
  10.       }
  11.     }
  12.   }
  13. }

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Irish analyzer internals

The irish analyzer is built using the following components:

  • Tokenizer: standard

  • Token filters:

    • hyphenation (Irish)
    • elision (Irish)
    • lowercase (Irish)
    • stop (Irish)
    • keyword
    • stemmer (Irish)

Custom Irish analyzer

You can create a custom Irish analyzer using the following command:

  1. PUT /irish-index
  2. {
  3.   "settings": {
  4.     "analysis": {
  5.       "filter": {
  6.         "irish_stop": {
  7.           "type": "stop",
  8.           "stopwords": "_irish_"
  9.         },
  10.         "irish_elision": {
  11.           "type":       "elision",
  12.           "articles":   [ "d", "m", "b" ],
  13.           "articles_case": true
  14.         },
  15.         "irish_hyphenation": {
  16.           "type":       "stop",
  17.           "stopwords":  [ "h", "n", "t" ],
  18.           "ignore_case": true
  19.         },
  20.         "irish_lowercase": {
  21.           "type":       "lowercase",
  22.           "language":   "irish"
  23.         },
  24.         "irish_stemmer": {
  25.           "type": "stemmer",
  26.           "language": "irish"
  27.         },
  28.         "irish_keywords": {
  29.           "type": "keyword_marker",
  30.           "keywords": []
  31.         }
  32.       },
  33.       "analyzer": {
  34.         "irish_analyzer": {
  35.           "type": "custom",
  36.           "tokenizer": "standard",
  37.           "filter": [
  38.             "irish_hyphenation",
  39.             "irish_elision",
  40.             "irish_lowercase",
  41.             "irish_stop",
  42.             "irish_keywords",
  43.             "irish_stemmer"
  44.           ]
  45.         }
  46.       }
  47.     }
  48.   },
  49.   "mappings": {
  50.     "properties": {
  51.       "content": {
  52.         "type": "text",
  53.         "analyzer": "irish_analyzer"
  54.       }
  55.     }
  56.   }
  57. }

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Generated tokens

Use the following request to examine the tokens generated using the analyzer:

  1. POST /irish-index/_analyze
  2. {
  3.   "field": "content",
  4.   "text": "Tá mic léinn ag staidéar in ollscoileanna na hÉireann. Is iad a gcuid uimhreacha ná 123456."
  5. }

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The response contains the generated tokens:

  1. {
  2.   "tokens": [
  3.     {"token": "tá","start_offset": 0,"end_offset": 2,"type": "<ALPHANUM>","position": 0},
  4.     {"token": "mic","start_offset": 3,"end_offset": 6,"type": "<ALPHANUM>","position": 1},
  5.     {"token": "léinn","start_offset": 7,"end_offset": 12,"type": "<ALPHANUM>","position": 2},
  6.     {"token": "staidéar","start_offset": 16,"end_offset": 24,"type": "<ALPHANUM>","position": 4},
  7.     {"token": "ollscoileanna","start_offset": 28,"end_offset": 41,"type": "<ALPHANUM>","position": 6},
  8.     {"token": "héireann","start_offset": 45,"end_offset": 53,"type": "<ALPHANUM>","position": 8},
  9.     {"token": "cuid","start_offset": 64,"end_offset": 69,"type": "<ALPHANUM>","position": 12},
  10.     {"token": "uimhreacha","start_offset": 70,"end_offset": 80,"type": "<ALPHANUM>","position": 13},
  11.     {"token": "123456","start_offset": 84,"end_offset": 90,"type": "<NUM>","position": 15}
  12.   ]
  13. }