Rebooting to support parsing of spreadsheet formulas and cell references as they appear in unevaluated expressions. This work is still in progress but a CRAN update is required now to update a test for testthat v1.0.x.
Package is beginning to implement classes and methods related to cell location and reference from 'Spreadsheet Implementation Technology' by Peter Sestoft, MIT Press, 2014.
New classes:
cell_addr: one or more absolute cell addressesra_ref: single absolute, relative, or mixed cell referenceThe two components of a cell_limits object now correspond NOT to row and column limits, but rather to the upper left and lower right cells of the rectangle. See #6. It was too confusing to have different conventions for the object and its print method.
If the maximum row or column is specified, but the minimum is not, then we automatically set the associated minimum to 1, instead of leaving as NA.
The header argument of anchored() has been renamed to col_names, for greater consistency with readr, readxl, and googlesheets.
Added a NULL method for as.cell_limits generic so that as.cell_limits(NULL) returns default, degenerate cell limits, i.e. the min and max for rows and columns are uniformly NA.
A cell_limits object now inherits from "list".