codespan_preprocessed

This is an extension of the very useful crate codespan_reporting to deal with preprocessed file through the well-knownm4 or cpp.

Using such a preprocessor allows, among a lost of things, the inclusion of many files which are identified in the bytes sequence with preprecessor directive as:

#line 42 "/my/preprocessed/file"

This directive breaks the location of the source and so should be correctly processed to make correct location for error reporting.

This is the purpose of this crate: taking a preprocessor output and managing the different underlying locations inside it.

Example

```rust use codespanreporting::diagnostic::Diagnostic; use codespanreporting::term::termcolor::{ColorChoice, StandardStream}; use codespan_preprocessed::PreprocessedFile;

fn main() { let file = PreprocessedFile::new(
unindent::unindent( r#" #line 1 "top_file" a first statement; another one

            #line 1 "included_file"
            continue...

            #line 5
            another line
            the last one
        "#,
    ),
);

let diagnostic = Diagnostic::note()
        .with_message("this is just an example")
        .with_labels(vec![
            file.primary_label(113..117).with_message("do you see that ?"),
            file.secondary_label(21..26).with_message("is it related to this ?")
        ]);

// We now set up the writer and configuration, and then finally render the
// diagnostic to standard error.
// (see `codespan_reporting` documention for more details)

let writer = StandardStream::stderr(ColorChoice::Always);
let config = codespan_reporting::term::Config::default();

term::emit(&mut writer.lock(), &config, &file, &diagnostic);

} ```