The `csc151` package provides three basic operations for working with
text files: `file->chars`, which reads the contents of a text file and
presents the contents as a list of characters; `file->words`, which
reads the contents of a text file and presents the contents as a list
of strings, each of which represents one "word" in the file (using a
simple metric for "word"); and `read->lines`, which reads the contents
of a text file and presents the contents as a list of strings, each
of which represents one line of the input file.