Function parse_error_of 

pub fn parse_error_of(input: &str) -> Option<ParseError>

The parse error for input, in the AUTHOR’s own file coordinates — the implicit-## Main wrap and the stdlib-prelude splice both undone, exactly as with_parsed_program_checked undoes them for its callers — or None when input parses. A pure parse check with no ## Require gate: a caller that wants to render its OWN caret block (largo run --interpret, matching what largo check already shows) takes the located error from here instead of formatting whatever Result::Err variant happened to reach it.