Filter
In the real world, a filter is a device that separates one substance from another. See also Enumerable#filter, an alias for #select.
In Nanoc, a filter transforms data, e.g. from Markdown to HTML.
A better name in Nanoc would be transform.
Identifier vs. path
Identifiers are technically paths as of Nanoc 4 (at least when not using the legacy identifiers), but the distinction is not clear.
A better name for an identifier could be:
- input path vs. output path
- raw path vs. compiled path
- raw path vs. cooked path
- raw path vs. baked path