pub fn implicit_main(source: &str) -> Option<String>Expand description
IMPLICIT MAIN: a source with no ## headers whose first non-blank line
reads as an imperative statement runs as its own ## Main body, so a bare
script runs rather than parsing as logic prose.
Natural-language documents (no statement-keyword opening) are untouched.
Returns the wrapped source, or None when the input is not a bare script.