pub fn split(source: &str, delim: Delimiter) -> DocumentResult<Parts<'_>>Expand description
Split source into its frontmatter spans for the given delimiter.
The opening delimiter must be the file’s very first line (no leading blank
lines, no BOM). The closing delimiter is the next line equal to the marker
at column zero. A missing opening or closing fence is a DocumentError,
never a silent “there is no frontmatter, treat the whole file as body”.