- reader:procedure
Constructs a reader procedure for the given input format specification and returns two values: the reader procedure and the input stream. The reader procedure is of the form LAMBDA STRM -> RECORD STRM. It reads one record from the given input stream and by default returns the record as a list of values and the remainder of the input stream. If optional argument RETURN-NAMES is true, the record will be returned as an alist where the keys are column names (if COLUMN-NAMES is provided) or indices, and the values are the column values.
- Argument INPUT is a string or a port.
- Argument DELIMITER specifies the delimiter character (default is #\,). If its value is #f, then COLUMNN-WIDTHS must be specified.
- Argument EOL specifies the end-of-line string (default is "\n").
- Argument COMMENT-CHAR specifies a comment character: the reader will skip all lines that start with this character (default: none).
- Argument NA specifies a default value to be supplied when a given field is empty (default: none).
- Argument COLUMN-NAMES specifies column names which will be used if RETURN-NAMES is true (default: none). If COLUMN-NAMES is the symbol 'header then the column names will be inferred from the first line in the input.
- Argument COLUMN-WIDTHS specifies column widths which will be used if DELIMITER is not specified (default: none).
- Argument RETURN-NAMES specifies that each returned record will have the form of an alist with column name and value pairs. If COLUMN-NAMES is not provided, the column index will be used as key instead.