Sometimes, you need some help to see how the parse process is working. A simple measure is to include a print or probe statement with certain matches, such as when parsing the rate string in the Searching, extracting, and changing section:
rate: "<title>1 USD = 0.81191502 EUR</title>"parse rate [thru "<title>" copy data to "</title>" (probe data) thru ">"];"1 USD = 0.81191502 EUR";== true
Or you could simply print out:
(print "found a </title>"), to indicate that a match was found.
Let's apply this to the last example from the previous section:
rule: [start: word! string! finish: ( print ["-->" start] print ["<--" finish] append result copy/part start finish )]
This prints out the following:
--> print x is smaller ...