ra_ref class

The ra_ref class is used to represent a single relative, absolute, or mixed cell reference, presumably found in a formula. When row_abs is TRUE, it means that row_ref identifies a specific row in an absolute sense. When row_abs is FALSE, it means that row_ref holds a positive, zero, or negative offset relative to the address of the cell containing the formula that contains the associated cell reference. Ditto for col_abs and col_ref.

ra_ref(row_ref = 1L, row_abs = TRUE, col_ref = 1L, col_abs = TRUE,
  sheet = NA_character_, file = NA_character_)

Arguments

row_ref

integer, row or row offset

row_abs

logical indicating whether row_ref is absolute or relative

col_ref

integer, column or column offset

col_abs

logical indicating whether col_ref is absolute or relative

sheet

the name of a sheet (a.k.a. worksheet or tab)

file

the name of a file (a.k.a. workbook)

Value

a ra_ref object

Details

A ra_ref object can also store the name of a sheet and a file, though these will often be NA. A cell reference in a formula can potentially be qualified like this: [my_workbook.xlxs]Sheet1!R2C3. In Testoft (2014), he creates an entirely separate class for this, a cell_ref, which consists of a sheet- and file-ignorant ra_ref object and a sheet reference (he doesn't allow formulas to refer to other files). I hope I don't regret choosing a different path.

Reference

Spreadsheet Implementation Technology: Basics and Extensions Peter Sestoft MIT Press 2014

Examples

ra_ref()
#> <ra_ref>
#>    row: 1 (abs)
#>    col: 1 (abs)
#>  R1C1
ra_ref(row_ref = 3, col_ref = 2)
#> <ra_ref>
#>    row: 3 (abs)
#>    col: 2 (abs)
#>  R3C2
ra_ref(row_ref = 10, row_abs = FALSE, col_ref = 3, col_abs = TRUE)
#> <ra_ref>
#>    row: 10 (rel)
#>    col: 3 (abs)
#>  R[10]C3
ra_ref(sheet = "a sheet")
#> <ra_ref>
#>    row: 1 (abs)
#>    col: 1 (abs)
#>  sheet: 'a sheet'
#>  'a sheet'!R1C1