Read data from a flat file with type schema preservation

Reads a data frame from a flat file format (CSV by default) using a companion parquet schema file to restore column types. This enables type-preserving round-trips for formats that don't natively preserve types.

Usage

ngr_fs_type_read(path, format = "csv", schema_suffix = "schema")

Arguments

path

Character. Path to the file to read. A companion schema file must exist.

format

Character. File extension to replace when finding the schema file. Default is "csv".

schema_suffix

Character. Suffix appended to base filename for the schema file. Default is "schema" (e.g., data.csv -> data_schema.parquet). Use "" for no suffix (e.g., data.csv -> data.parquet).

Value

A tibble::tibble with column types restored from the schema file.

See also

ngr_fs_type_write() for writing files with type preservation

Other fs: ngr_fs_copy_if_missing(), ngr_fs_id_missing(), ngr_fs_type_write()

Other serialization: ngr_fs_type_write()

Examples

if (FALSE) { # \dontrun{
# Create example data with various types
df <- data.frame(
  int_col = 1:3L,
  dbl_col = c(1.1, 2.2, 3.3),
  chr_col = c("a", "b", "c"),
  date_col = as.Date(c("2024-01-01", "2024-01-02", "2024-01-03")),
  lgl_col = c(TRUE, FALSE, TRUE)
)

# Write to temporary file
path <- tempfile(fileext = ".csv")
ngr_fs_type_write(df, path)

# Read back with types preserved
df2 <- ngr_fs_type_read(path)
str(df2)

# Compare types
sapply(df, class)
sapply(df2, class)
} # }