| //! The preprocessing we apply to doc comments. |
| //! |
| //! structopt works in terms of "paragraphs". Paragraph is a sequence of |
| //! non-empty adjacent lines, delimited by sequences of blank (whitespace only) lines. |
| |
| use crate::attrs::Method; |
| use quote::{format_ident, quote}; |
| use std::iter; |
| |
| pub fn process_doc_comment(lines: Vec<String>, name: &str, preprocess: bool) -> Vec<Method> { |
| // multiline comments (`/** ... */`) may have LFs (`\n`) in them, |
| // we need to split so we could handle the lines correctly |
| // |
| // we also need to remove leading and trailing blank lines |
| let mut lines: Vec<&str> = lines |
| .iter() |
| .skip_while(|s| is_blank(s)) |
| .flat_map(|s| s.split('\n')) |
| .collect(); |
| |
| while let Some(true) = lines.last().map(|s| is_blank(s)) { |
| lines.pop(); |
| } |
| |
| // remove one leading space no matter what |
| for line in lines.iter_mut() { |
| if line.starts_with(' ') { |
| *line = &line[1..]; |
| } |
| } |
| |
| if lines.is_empty() { |
| return vec![]; |
| } |
| |
| let short_name = format_ident!("{}", name); |
| let long_name = format_ident!("long_{}", name); |
| |
| if let Some(first_blank) = lines.iter().position(|s| is_blank(s)) { |
| let (short, long) = if preprocess { |
| let paragraphs = split_paragraphs(&lines); |
| let short = paragraphs[0].clone(); |
| let long = paragraphs.join("\n\n"); |
| (remove_period(short), long) |
| } else { |
| let short = lines[..first_blank].join("\n"); |
| let long = lines.join("\n"); |
| (short, long) |
| }; |
| |
| vec![ |
| Method::new(short_name, quote!(#short)), |
| Method::new(long_name, quote!(#long)), |
| ] |
| } else { |
| let short = if preprocess { |
| let s = merge_lines(&lines); |
| remove_period(s) |
| } else { |
| lines.join("\n") |
| }; |
| |
| vec![Method::new(short_name, quote!(#short))] |
| } |
| } |
| |
| fn split_paragraphs(lines: &[&str]) -> Vec<String> { |
| let mut last_line = 0; |
| iter::from_fn(|| { |
| let slice = &lines[last_line..]; |
| let start = slice.iter().position(|s| !is_blank(s)).unwrap_or(0); |
| |
| let slice = &slice[start..]; |
| let len = slice |
| .iter() |
| .position(|s| is_blank(s)) |
| .unwrap_or_else(|| slice.len()); |
| |
| last_line += start + len; |
| |
| if len != 0 { |
| Some(merge_lines(&slice[..len])) |
| } else { |
| None |
| } |
| }) |
| .collect() |
| } |
| |
| fn remove_period(mut s: String) -> String { |
| if s.ends_with('.') && !s.ends_with("..") { |
| s.pop(); |
| } |
| s |
| } |
| |
| fn is_blank(s: &str) -> bool { |
| s.trim().is_empty() |
| } |
| |
| fn merge_lines(lines: &[&str]) -> String { |
| lines.iter().map(|s| s.trim()).collect::<Vec<_>>().join(" ") |
| } |