I'm trying to build a site with Hugo and having a hard time understanding some of their documentation. Specifically, when displaying frontmatter in a template.
There are functions you can preform on variables inside the handle bars. ex: {{ range .Data.Pages }} What is range? I can't find any documentation on what these functions do. Or is it just plain Go code and anything Go is fair game? Just looking for documentation so I can figure out what I need.
These are functions that have specifically been made available to Go templates (you can't just use any Go functions). They include the built-in functions documented in the golang.org template docs which JimB linked to in his comment, and also Hugo-specific functions which are documented on the Hugo template functions page.