Find all codes that logically precede the specified codes. For instance, code "ABC" ("Anhyturbels") returns "AA" ("Histels") "ABA" ("Histoturbels") and "ABB" ("Aquiturbels"). Use in conjunction with a lookup table that maps Order, Suborder, Great Group and Subgroup taxa to their codes (see taxon_code_to_taxon and taxon_to_taxon_code).

preceding_taxon_codes(codes)

## Arguments

codes A character vector of codes to calculate preceding codes for

## Value

A list with equal length to input vector; one character vector per element

## Details

Accounts for Keys that run out of capital letters (more than 26 subgroups) and use lowercase letters for a unique subdivision within the "fourth character position."

decompose_taxon_code, taxon_code_to_taxon, taxon_to_taxon_code

#> $ABCDe #> [1] "AA" "ABA" "ABB" "ABCA" "ABCB" "ABCC" "ABCD" "ABCDa" "ABCDb" #> [10] "ABCDc" "ABCDd" "ABCDe" #> #>$BCDEf