Append a row to the project accumulator

Internal helper used by save_output() to record one row of metadata to output_dir/accumulator.csv, creating the file (with headers) on first write and appending without headers thereafter.

Usage

.append_accumulator_row(row, output_dir = "output")

Arguments

row

A single-row data frame whose columns match .accumulator_columns() exactly, in order.

output_dir

Character. Directory containing (or to contain) accumulator.csv.

Value

The path to the accumulator, invisibly.

Details

When the accumulator already exists, its header is read and compared against the expected schema before appending. A mismatch aborts rather than appending misaligned rows to a file written under a different schema version.

NA values are written as empty fields. Any reader of this file must pass na.strings = "" to recover them as NA rather than as empty strings.