Replace a Value with NA Column Transform

Returns a transform that replaces a specific value with NA. Commonly used to convert empty strings to NA before comparison so that missing-data levels are triggered correctly. The result can be passed as the transform argument to il_compare() or il_block_on(), and composed with other transforms via il_transform(). On DuckDB and PostgreSQL, maps to SQL NULLIF.

Usage

il_nullif(value)

Arguments

value

The value to treat as missing.

Value

An il_column_transform closure.

Examples

tf <- il_nullif('')
tf(c('New York', '', 'Chicago'))
#> [1] "New York" NA         "Chicago" 

# Use before comparison to treat blank city as missing
spec <- il_spec() |>
  il_compare(city, cl_exact(), transform = il_nullif(''))