;; Extension — fuzzy matching via Levenshtein edit distance.
;; Corpus: 1 "color flavor"  2 "colour kitten"  3 "colored"
;; allTerms: color colored colour flavor kitten

(define
  fuzzy-setup
  "idx = indexDoc 3 \"colored\" (indexDoc 2 \"colour kitten\" (indexDoc 1 \"color flavor\" emptyIndex))\n")

(define
  fuzzy-cases
  (list
    (list
      "editDist substitution"
      "[editDist \"kitten\" \"sitten\"]"
      (list 1))
    (list "editDist equal" "[editDist \"abc\" \"abc\"]" (list 0))
    (list "editDist deletion" "[editDist \"abc\" \"ab\"]" (list 1))
    (list "editDist insertion" "[editDist \"ab\" \"abc\"]" (list 1))
    (list "editDist from empty" "[editDist \"\" \"abc\"]" (list 3))
    (list "editDist both empty" "[editDist \"\" \"\"]" (list 0))
    (list
      "editDist classic"
      "[editDist \"kitten\" \"sitting\"]"
      (list 3))
    (list
      "editDist color colour"
      "[editDist \"color\" \"colour\"]"
      (list 1))
    (list
      "editDist color colored"
      "[editDist \"color\" \"colored\"]"
      (list 2))
    (list
      "fuzzy terms dist 1"
      "fuzzyTerms 1 \"color\" idx"
      (list "color" "colour"))
    (list
      "fuzzy terms dist 2"
      "fuzzyTerms 2 \"color\" idx"
      (list "color" "colored" "colour"))
    (list "fuzzy terms exact" "fuzzyTerms 0 \"color\" idx" (list "color"))
    (list
      "fuzzy terms other word"
      "fuzzyTerms 1 \"flavour\" idx"
      (list "flavor"))
    (list
      "fuzzy docs dist 1"
      "fuzzyDocs 1 \"color\" idx"
      (list 1 2))
    (list
      "fuzzy docs dist 2"
      "fuzzyDocs 2 \"color\" idx"
      (list 1 2 3))
    (list "fuzzy docs none" "fuzzyDocs 1 \"zzzzz\" idx" (list))
    (list
      "fuzzy rank dist 1"
      "fuzzyRankTfIdf 1 \"color\" idx"
      (list 1 2))
    (list
      "fuzzy rank dist 2"
      "fuzzyRankTfIdf 2 \"color\" idx"
      (list 1 2 3))))

(define
  fuzzy-results
  (search-batch fuzzy-setup (map (fn (c) (nth c 1)) fuzzy-cases)))

(map-indexed
  (fn
    (i c)
    (hk-test (nth c 0) (nth fuzzy-results i) (nth c 2)))
  fuzzy-cases)

{:fail hk-test-fail :pass hk-test-pass :fails hk-test-fails}