new_file_definition_fwf_: Helper function for 'new_file_definition_fwf()'
In a-maldet/readall: Read FWF, DSV, EXCEL And SAS Files

Helper function for new_file_definition_fwf()

new_file_definition_fwf_(
  file_path,
  specification_files = NULL,
  cols = NULL,
  col_names = NULL,
  col_types = NULL,
  col_start = NULL,
  col_end = NULL,
  col_widths = NULL,
  file_meta = NULL,
  sep_width = NULL,
  skip_rows,
  na,
  decimal_mark,
  big_mark,
  trim_ws,
  n_max,
  encoding,
  to_lower,
  adapters = new_adapters(),
  cols_keep,
  extra_col_name = NULL,
  extra_col_val = NULL,
  extra_col_file_path,
  err_h,
  ...
)

`file_path`	A string holding the path to the data file.
`specification_files`	An optional character vector holding the paths to the files, where the file structure is described.
`cols`	An optional list argument, holding the column definitions. This argument can be used instead of the arguments `col_names`, `col_types`, `col_start`, `col_end`, `col_widths`, in order to define the column structure. If the argument `cols` is used, then non of the `col_` argument are allowed. If so, the `cols` argument has the following structure: It is list, where each list entry fully describes a single column. Each list entry must have the same subselection of the following possible list entries: `type`: (obligatoric) A string value defining the data type of the column. The following values are allowed: `"character"`, `"logical"`, `"integer"`, `"numeric"` and `"NULL"` (for skipping this column). In the case of SAS files the `type` information can be omitted, since the data type information is stored in the SAS data files, but the argument `type` can still be useful in order to check that the read data column have the expected data type. For SAS-Files this check is done automatically after reading the data with `read_data()`. `name`: (optional) A string holding the column name. `start`: (optional) A number holding the position of the first character of the column. `end`: (optional) A number holding the position of the last character of the column. `width` (optional) A numeric holding the number characters of the column. `col_meta`: (optional) A col_meta class object, holding some meta information for the specific column (column description, possible column values + descriptions of possible column values). For details see section meta information*.
`col_names`	An optional character vector holding the names of the columns. If omitted, then the strings `"x1"`, `"x2"`, ... will be used. In the case of DSV or EXCEL files: If the argument `header` is set to `TRUE`, then the column names given in the data header will be used instead. If `col_names` is also supplied, then the column names given in the DSV, EXCEL or SAS file will be compared with the names given in `col_names`. Sometimes it is useful, to have the column names to be automatically transformed to lower case (directly after reading the date, but before comparing the column names). This can be achieved by setting `to_lower = TRUE`. Generally, the argument `cols` can be used instead, in order to define the column names. If the argument `cols` is not `NULL`, then the argument `col_names` must be omitted.
`col_types`	A character vector defining the data types for each column. The following strings are allowed: `"character"`, `"logical"`, `"integer"`, `"numeric"` and `"NULL"` (for skipping this column). Generally, the argument `cols` can be used instead, in order to define the column types. If the argument `cols` is not `NULL`, then the argument `col_types` must be omitted. In the case of SAS files the `col_types` information can be omitted, since the data type information is stored in the SAS data files, but the argument `col_types` can still be useful in order to check the read data files, if the data types are as expected. For SAS-Files this check is done automatically after reading the data with `read_data()`
`col_start`	An optional numeric vector holding the positions of the first character of each column. Generally, the argument `cols` can be used instead, in order to define the column start positions. If the argument `cols` is not `NULL`, then the argument `col_start` must be omitted.
`col_end`	An optional numeric vector holding the positions of the last character of each column. The last vector entry (for the most right column) is the only entry that can be `NA`. In this case, the most right cells are always read till the new line character. Generally, the argument `cols` can be used instead, in order to define the column end positions. If the argument `cols` is not `NULL`, then the argument `col_end` must be omitted.
`col_widths`	An optional numeric vector holding the numbers of characters of each column. Generally, the argument `cols` can be used instead, in order to define the column widths. If the argument `cols` is not `NULL`, then the argument `col_widths` must be omitted.
`file_meta`	An optional file_meta class object, holding some meta information for each data column (column description, possible column values + descriptions of possible column values). For details see section meta information. If the argument `cols` is not `NULL`, then the argument `file_meta` must be omitted.
`sep_width`	An optional number, defining the number of characters between each column (often `0`).
`skip_rows`	The number of rows to be skipped. In the case of DSV or EXCEL files: If the argument `header` is set to `TRUE`, then the first row is always assumed to be the header row.
`na`	A string representing missing values in the data file.
`decimal_mark`	A character, defining the decimal separator in numeric columns. Only the strings `"."` and `","` are allowed.
`big_mark`	A character, defining the thousands separator in numeric columns. Only the strings `"."` and `","` are allowed.
`trim_ws`	A logical value, defining if the character values should be stipped of all leading and trailing white spaces.
`n_max`	A number, defining the maximum number of rows to be read. If `n_max = Inf`, then all available rows will be read.
`encoding`	A string, defining which encoding should be assumed when reading the data file. The following valuels are allowed: `"UTF-8"`: For UTF-8 encoded files. `"latin1"`: For ISO 8859-1 (also called Latin-1) encoded files. This encoding is almost the same as Windows-1252 (also called ANSI). They differ only in 32 symbol codes (special symbols that are rarely used). In the case of SAS files, it is possible to set `encoding = NULL`. In this case, the encoding defined in the SAS data file header will be used.
`to_lower`	A logical flag, defining if the names of the columns should be transformed to lower case after reading the data set (by calling `read_data()`). This transformation will be applied before comparing the column names (in the case of SAS-Files or DSV- and EXCE-Files with `header = TRUE`). In the case of `new_file_definition()` the `to_lower` argument overwrites the `to_lower` argument in the file_structure class object given in `file_structure`. If `to_lower` is omitted, then the `file_structure` class object remains unchanged. In the case of `new_file_definition_fwf()`, `new_file_definition_dsv()`, `new_file_definition_excel()` or `new_file_definition_sas()` the argument `to_lower` must either be `TRUE` or `FALSE`.
`adapters`	An optional list argument, holding a list of adapter functions (See section adapters).
`cols_keep`	Either `TRUE` or a character vector. If set to `TRUE`, then all columns of the data are kept when calling `read_data()`. If `cols_keep` character vector, then the values in `cols_keep` represent the names of the columns, which are kept when calling `read_data()`.
`extra_col_name`	An optional string, which defines the column, which will be added to the data set (after reading it with function `read_data()`). Each entry of the column will have the single value given in `extra_col_val`. For example: This column is useful when reading similar data files for separate years (one could pass the current data set year to `extra_col_name` and set `extra_col_name = "year"`). If `extra_col_name` is omitted, no column will be added to the data set and then `extra_col_val` must be omitted as well. additional column with the column name, given in `extra_col_name`. If omitted, then no column will be added to the data set and the argument `extra_col_name` must be omitted as well.
`extra_col_val`	An optional value (any atomic type), which will be added (after reading the data set with function `read_data()`) as an additional column with the column name, given in `extra_col_name`. For example: This column is useful when reading similar data files for separate years (one could pass the current data set year to `extra_col_name` and set `extra_col_name = "year"`). If omitted, then no column will be added to the data set and the argument `extra_col_name` must be omitted as well.
`extra_col_file_path`	Either `FALSE` or a string. If set to `FALSE` no file-path-column will be added to the data set, when calling `read_data()`. If the argument `extra_col_file_path` is a string, then a column holding the file path of the data file will be added to the read data set, when calling `read_data()`. The string of `extra_col_file_path` will be used as column name for this additional column.
`err_h`	An error handler
`...`	Additional function arguments for `readr::read_fwf()` in case of FWF files `utils::read.delim()` in case of DSV files `readxl::read_excel()` in case of EXCEL files