use std::fs::File; use std::io::{BufRead, BufReader, Read, Write}; use abnf_to_pest::render_rules_to_pest; fn main() -> std::io::Result<()> { // TODO: upstream changes to grammar // let abnf_path = "../dhall-lang/standard/dhall.abnf"; let abnf_path = "src/dhall.abnf"; let visibility_path = "src/dhall.pest.visibility"; let pest_path = "src/dhall.pest"; println!("cargo:rerun-if-changed={}", abnf_path); println!("cargo:rerun-if-changed={}", visibility_path); let mut file = File::open(abnf_path)?; let mut data = Vec::new(); file.read_to_end(&mut data)?; data.push('\n' as u8); let mut rules = abnf_to_pest::parse_abnf(&data)?; for line in BufReader::new(File::open(visibility_path)?).lines() { let line = line?; if line.len() >= 2 && &line[0..2] == "# " { rules.get_mut(&line[2..]).map(|x| x.silent = true); } } let mut file = File::create(pest_path)?; writeln!(&mut file, "// AUTO-GENERATED FILE. See build.rs.")?; // TODO: this is a cheat; properly support RFC3986 URLs instead rules.remove("url_path"); writeln!(&mut file, "url_path = _{{ path }}")?; rules.remove("simple_label"); writeln!( &mut file, "simple_label = {{ keyword ~ simple_label_next_char+ | !keyword ~ simple_label_first_char ~ simple_label_next_char* }}" )?; rules.remove("nonreserved_label"); writeln!( &mut file, "nonreserved_label = _{{ !(builtin ~ !simple_label_next_char) ~ label }}" )?; // Setup grammar for precedence climbing rules.remove("operator_expression"); writeln!(&mut file, r##" import_alt = {{ "?" ~ whsp1 }} bool_or = {{ "||" }} natural_plus = {{ "+" ~ whsp1 }} text_append = {{ "++" }} list_append = {{ "#" }} bool_and = {{ "&&" }} natural_times = {{ "*" }} bool_eq = {{ "==" }} bool_ne = {{ "!=" }} operator = _{{ equivalent | bool_ne | bool_eq | natural_times | combine_types | prefer | combine | bool_and | list_append | text_append | natural_plus | bool_or | import_alt }} operator_expression = {{ application_expression ~ (whsp ~ operator ~ whsp ~ application_expression)* }} "##)?; writeln!( &mut file, "final_expression = ${{ SOI ~ complete_expression ~ EOI }}" )?; writeln!(&mut file)?; writeln!(&mut file, "{}", render_rules_to_pest(rules).pretty(80))?; Ok(()) }