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Search an index

Source: R/search.R
tnt_search.Rd

Runs a BM25 full-text search and returns the top matches as a tibble. Supports structured filters, result ordering and snippet highlighting.

Usage

tnt_search(
  idx,
  query = "",
  limit = 10L,
  fields = NULL,
  filter = NULL,
  highlight = NULL,
  snippet_chars = 150L,
  order_by = NULL,
  desc = TRUE
)

Arguments

idx

A tnt_index.

query

A query string in tantivy's query syntax. The empty string "" matches all documents (useful with filter).

limit

Maximum number of results. Defaults to 10.

fields

<tidy-select> Text fields searched for bare (unqualified) query terms. Defaults to all indexed text fields.

filter

Either a tantivy query string, or a comparison expression such as year >= 2020 & source == "globo". Supported operators: ==, %in%, >, >=, <, <=, combined with & and |.

highlight

<tidy-select> Stored text fields to return highlighted snippets for. One <field>_snippet column is added per selected field, with matches wrapped in <b> tags.

snippet_chars

Maximum snippet length in characters. Defaults to 150.

order_by

<tidy-select> A single numeric/date fast field to order by instead of BM25 score. When set, score is NA.

desc

Logical. Order descending (the default) when order_by is set.

Value

A tibble with a score column, every stored field, and any requested *_snippet columns.

See also

tnt_count(), tnt_index_df()

Examples

df <- data.frame(
  id = 1:3,
  title = c("Quick brown fox", "Lazy dog", "Brown bear"),
  year = c(2019L, 2021L, 2023L)
)
idx <- tnt_index_df(df, text = title, filters = year, stemmer = "english")
tnt_search(idx, "brown")
#> # A tibble: 2 × 4
#>   score    id title            year
#>   <dbl> <dbl> <chr>           <dbl>
#> 1 0.499     3 Brown bear       2023
#> 2 0.421     1 Quick brown fox  2019
tnt_search(idx, "brown", filter = year >= 2021)
#> # A tibble: 1 × 4
#>   score    id title       year
#>   <dbl> <dbl> <chr>      <dbl>
#> 1 0.499     3 Brown bear  2023
tnt_search(idx, "fox", highlight = title)
#> # A tibble: 1 × 5
#>   score    id title            year title_snippet         
#>   <dbl> <dbl> <chr>           <dbl> <chr>                 
#> 1 0.878     1 Quick brown fox  2019 Quick brown <b>fox</b>