Print3

A cat-like programming built for C3 source files, it will try to highlight the source like inside an editor.

Example:

A special thank you to @ManuLinares for the regex that selects any valid C3 number (including the fun stuff like 1.3e-39 or 32ull)!

Usage:

./print3 [options...] file(s)

Print C3 files with colours. A bit akin to 'cat' or 'bat'.

Options and files can generally be mixed, only when an option requires
an argument, it is expected to follow directly behind.

Available options:
-h, --help              Show this help message

--tabsize <number>      Amount of spaces to print for a tab character
-n, --number            Show line numbers
--nonumber              Show no line numbers
--nrformat <text>       Format for numbers (f.e. "%d | ").
--line-start <number>   Start printing from this line (inclusive)
--line-stop <number>    Stop printing at this line (inclusive)
--print-buffer-size <number>
                      Set the size of the print buffer (bytes, default 128)

--colour-<thing> <text> Set the colour for <thing> to <text>, should be
                      specified in "#RRGGBB" format. Available things:
                      at, call, comment, comptime_ident, constant, ident,
                      keyword, member, number, string, symbol, type.

Allowed format for --nrformat:
<pre>%[-][0._][1-9]d<post>

- <pre> and <post> are static strings printed around the line numbe
- Starts with '%' and ends with 'd'
- Optionally '-' to set alignment to left (default right)
- Optionally '0', '.' or '_' to use as padding character
- Optionally 1-9 as minimum width specifier (default 3)

Examples: "%d", "line - %-5d :"

Known issues:

• --maxcol and --ellipsis currently do not work
• --colour-<thing> colour parsing does not seem to work

Improvement points:

• profile performance and improve where possible
• add json config file for easier default overrides
• add either builtin pager, or auto-pipe to less or more from within print3

Fun IO optimization

I spent some time looking at optimizing print3 , and perf showed me that C3's printf machine took quite some time. I decided to try and replace all printf occurences with multiple print calls and see if that speeded up things:

io::printf(
    "%s%s%s",
    Ansi.BRIGHT_GREEN,
    word,
    Ansi.RESET
);
// became
io::print(Ansi.BRIGHT_GREEN);
io::print(word);
io::print(Ansi.RESET);

This sped up things by almost 2.5x.

Some slight tweaking to this by caching stdout and creating my own BufferedOutput abstraction, hyperfine showed some fun results:

Benchmark 1: ./build/old_print3 long.c3
  Time (mean ± σ):     178.5 ms ±   1.7 ms    [User: 167.0 ms, System: 10.7 ms]
  Range (min … max):   175.9 ms … 184.3 ms    100 runs

Benchmark 2: ./build/print3 long.c3
  Time (mean ± σ):      47.1 ms ±   0.6 ms    [User: 35.8 ms, System: 11.1 ms]
  Range (min … max):    45.7 ms …  48.5 ms    100 runs

Summary
  ./build/print3 long.c3 ran
    3.79 ± 0.06 times faster than ./build/old_print3 long.c3

In short: when the main goal of your application is printing a file to the terminal, spend some time optimising that printing part. The standard library is made for ergonomics, not for raw speed in specialised usecases.