fputk: Apply Format Using a Composite Key

In ksformat: 'SAS'-Style 'PROC FORMAT' for R

Apply Format Using a Composite Key

Description

Convenience wrapper around [fput()] that pastes multiple vectors together into a composite key before lookup. Useful when a format is keyed on the combination of several columns (e.g., 'USUBJID|VISITNUM').

Usage

fputk(..., format, sep = "|", keep_na = FALSE, na_as_string = FALSE)

Arguments

...	Vectors to paste together into a composite key. All vectors are recycled to a common length by [paste()].
format	A [ks_format] object or a registered format name (character string).
sep	Separator inserted between the pasted components (default '"|"').
keep_na	If 'TRUE', 'NA' inputs remain 'NA' in the output instead of being mapped via '.missing'. Passed through to [fput()].
na_as_string	If 'FALSE' (default), an 'NA' in any component propagates to the composite key (restored to 'NA_character_' after the [paste()] step) so that [fput()] can apply '.missing' handling. If 'TRUE', the literal string '"NA"' produced by [paste()] is kept, which is useful when the format was built with composite keys via 'fmap(paste(..., sep = "|"), values)' — because [paste()] converts 'NA' to '"NA"' on both sides, the round-trip lookup then matches.

Value

A character vector of formatted labels, the same length as the (recycled) input vectors.

See Also

[fput()], [fputn()], [fputc()], [finputk()]

Examples

# Build a lookup keyed on two columns
fnew(
  "A|1" = "2025-01-15",
  "A|2" = "2025-02-20",
  "B|1" = "2025-03-10",
  .other = "NOT FOUND",
  name = "visit_date",
  type = "character"
)

subj  <- c("A", "A", "B", "B")
visit <- c(1, 2, 1, 3)

fputk(subj, visit, format = "visit_date")
# -> "2025-01-15" "2025-02-20" "2025-03-10" "NOT FOUND"

fclear()

# Composite key with NA components matching a paste()-built format
fnew(
  fmap(
    paste(c("CHEM", "COAG"), c("ALB", "INR"), c("g/L", NA), sep = "|"),
    c("ALB", "INR")
  ),
  name = "lb_param", type = "character"
)

fputk(c("CHEM", "COAG"), c("ALB", "INR"), c("g/L", NA),
      format = "lb_param", na_as_string = TRUE)
# -> "ALB" "INR"

fclear()

ksformat documentation built on May 21, 2026, 9:07 a.m.