gleamunison/formatter
Opinionated formatter for gleamunison surface syntax (roadmap 9.2).
One rule, no configuration:
- a form is flat when it fits in 72 columns at its indent;
- otherwise it breaks after its head, children one per line at +2;
- when the head is an atom, the first child joins the opening line
if it fits flat (the
(define name …)convention).
Formatting is a pure function of the parse tree, so it is idempotent by construction. Comments are data, not casualties: a comment before a form stays before it, a comment on a form’s line trails that line, and a comment written inside a form stays inside it, on the line above the child that followed it. A comment inside a form forces that form to break, because flat text has nowhere to put one and dropping it is not an option. ’x prints as (quote x).
Values
pub fn format_source(
src: String,
) -> Result(String, lexer.ParseError)Format a whole source file: every top-level form on its own line(s), forms separated by single newlines, comments preserved in place, trailing newline at the end.