If you've followed the progress from the last chapter, per data chunk, you would have written out four kinds of files that represent all the data we've generated:
<file-name>-tick.edn <file-name>-sma.edn <file-name>-ema.edn <file-name>-bol.edn
Since we've named the files appropriately in our list of
many-files, we can use the
filter function to isolate on any condition—in this case, we'll isolate only one type of file.
For our predicate function, we can use a regular expression to search for a string pattern in a filename. Clojure represents regular expressions with a string prefixed by a hash such as
#"". So, the
re-matches function, for example, takes a regular expression and string ...