A registry of helper functions for Go text/template / html/template. All() returns a map[string]any (a template.FuncMap) covering compare, arrays, date, currency, HTML, math, logic, and string helpers. Part of rosetta.
Wire it in with template.New("…").Funcs(funcmap.All()).
What matters here
Template functions report-and-swallow their errors; they do not return them. Go template functions that return an error abort rendering, so helpers like json, jsonIndent, and markdown instead call derp.Report(...) on failure and return an empty/safe string. This is deliberate — a single bad value should not blow up a whole page render. Don't "fix" these to return errors.
All() rebuilds the map on every call. It is meant to be called once at template-parse time, not per-request in a hot path. Each call allocates a fresh map and re-registers every category.
HTML-producing helpers depend on the html package's escaping/sanitizing. Output safety (e.g. markdown, the HTML helpers) is only as strong as that package — changes to escaping there affect what these template funcs emit.