Skip to contents

Find First Element with Key >= Query

Source: R/50-ordered_sequence-ops.R
lower_bound.Rd

Find First Element with Key >= Query

Usage

lower_bound(x, key)

Arguments

x

An ordered_sequence.

key

Query key.

Value

A list with fields:

  • found: logical flag.

  • index: one-based position of the first match, or NULL.

  • value: matched element, or NULL.

  • key: matched key, or NULL.

Details

lower_bound() finds the first element with key >= key. This includes an exact key match when present, which is useful for starting equality or inclusive range scans.

See also

upper_bound()

Examples

x <- ordered_sequence("a", "b", "c", keys = c(1, 2, 2))
lower_bound(x, 2)
#> $found
#> [1] TRUE
#> 
#> $index
#> [1] 2
#> 
#> $value
#> [1] "b"
#> 
#> $key
#> [1] 2
#> 
lower_bound(x, 10)
#> $found
#> [1] FALSE
#> 
#> $index
#> NULL
#> 
#> $value
#> NULL
#> 
#> $key
#> NULL
#>