Constructing a suitable gitignore file for a simple inweb project.

§1. This section offers just one function, which constructs a .gitignore file by following a "prototype". 

    typedef struct gitignore_state {
        struct web *for_web;
        struct text_stream to_gitignore;
        int last_line_was_blank;     used to suppress runs of multiple blank lines
    } gitignore_state;

    void Git::write_gitignore(web *W, filename *prototype, filename *F) {
        gitignore_state MS;
        MS.for_web = W;
        MS.last_line_was_blank = TRUE;
        text_stream *OUT = &(MS.to_gitignore);
        if (STREAM_OPEN_TO_FILE(OUT, F, ISO_ENC) == FALSE)
            Errors::fatal_with_file("unable to write tangled file", F);
        WRITE("# This gitignore was automatically written by inweb -gitignore\n");
        WRITE("# and is not intended for human editing\n\n");
        TextFiles::read(prototype, FALSE, "can't open prototype file",
            TRUE, Git::copy_gitignore_line, NULL, &MS);
        STREAM_CLOSE(OUT);
        WRITE_TO(STDOUT, "Wrote gitignore file '%f' from script '%f'\n", F, prototype);
    }

The function Git::write_gitignore is used in 1/pc (§7.1), 3/ta (§13).

The structure gitignore_state is accessed in 6/mkf and here.

§2. 

    void Git::copy_gitignore_line(text_stream *line, text_file_position *tfp, void *X) {
        gitignore_state *MS = (gitignore_state *) X;
        text_stream *OUT = &(MS->to_gitignore);

        match_results mr = Regexp::create_mr();
        if (Regexp::match(&mr, line, L" *#%c*")) { Regexp::dispose_of(&mr); return; }
        if (Regexp::match(&mr, line, L" *{basics} *")) <Expand basics 2.1>;
        Regexp::dispose_of(&mr);

        <And otherwise copy the line straight through 2.2>;
    }

The function Git::copy_gitignore_line is used in §1, §2.1.

§2.1. <Expand basics 2.1> = 

        filename *prototype =
            Filenames::in_folder(path_to_inweb_materials, I"gitignorescript.txt");
        TextFiles::read(prototype, FALSE, "can't open make settings file",
            TRUE, Git::copy_gitignore_line, NULL, MS);
        Regexp::dispose_of(&mr);
        return;

This code is used in §2.

§2.2. <And otherwise copy the line straight through 2.2> = 

        if (Str::len(line) == 0) {
            if (MS->last_line_was_blank == FALSE) WRITE("\n");
            MS->last_line_was_blank = TRUE;
        } else {
            MS->last_line_was_blank = FALSE;
            WRITE("%S\n", line);
        }

This code is used in §2.