pp-binary-ints

An OCaml library for printing ints as unsigned binary integers.

The pretty printers are fairly customizable. The following options are supported.

Padding with zeros or spaces so that binary integers satisfy a minimum width.
Prefixing the integers 0b.
Separating every four bits with _ (underscore).
Choose if zeros should be printed similar to non-zero ints.

You can find documentation for the library here.

Installation

Install this library using opam.

opam install pp-binary-ints

Examples

The library provides four main functions.

Int.to_string converts ints to strings.
Int.make_to_string converts ints to strings, customizing the output with the optional arguments.
Int.pp_int is a simple Format module style pretty printer.
Int.make_pp_int is a customizable Format module style pretty printer with the customization controlled by the optional arguments.
Int.to_string_with is a lower level function converts ints to strings, customizing the output with the ~flags and ~min_width named arguments.
Int.pp_int_with is a lower level customizable Format module style pretty printer which takes in named arguments ~flags and ~min_width.

There are also versions available for int32, int64, and nativeint in the modules

Int32,
Int64, and
Nativeint.

A generic functor to generate binary-int printers is provided in the MakePP module.

The following demonstrates using the library in a toplevel/REPL.

Basic use

# #require "pp-binary-ints";;
# module Pp_Bin = Pp_binary_ints.Int;;
# Pp_Bin.to_string 0b110111;;
- : string = "0b11_0111"
# Pp_Bin.to_string 0o777;;
string = "0b1_1111_1111"
# Pp_Bin.to_string 1234;;
- : string = "0b100_1101_0010"

Customizing padding and minimum width

# #require "pp-binary-ints";;
# module Pp_Bin = Pp_binary_ints.Int;;
# (* Space Padding *);;
# Pp_Bin.make_to_string ~zero_padding:false ~min_width:13 () 0b110111;;
- : string = "0b11_0111    "
# (* Space padding on the left is also possible *);;
# Pp_Bin.make_to_string ~zero_padding:false ~left_padding:true ~min_width:13 () 0b110111;;
- : string = "    0b11_0111"

Separators and prefixes

# (* Turn off _ separators *);;
# Pp_Bin.make_to_string ~separators:false ~min_width:1 () 0b110111;;
- : string = "0b110111"
# (* Turn off prefixes *);;
# Pp_Bin.make_to_string ~prefix:false ~min_width:1 () 0b110111;;
- : string = "11_0111"
# (* Turn off both separatorns and prefixes *);;
# Pp_Bin.make_to_string ~separators:false ~prefix:false ~min_width:1 () 0b110111;;
- : string = "110111"

Zero printing behaviour

You can ask the library to treat 0 (zero) specially and not add a prefix to it. While it won't add a prefix to it, padding will still be added.

# (* Don't prefix zero *);;
# Pp_Bin.make_to_string ~zero_special:true ~min_width:1 () 0;;
- : string = "0"
# Pp_Bin.make_to_string ~zero_special:true ~min_width:1 () 0b110111;;
- : string = "0b11_0111"
(* Zero Padding still adds zeros to fill up the sapce *)
# Pp_Bin.make_to_string ~zero_special:true ~min_width:9 () 0;;
- : string = "0000_0000"
# Pp_Bin.make_to_string ~zero_special:true ~min_width:9 () 0b110111;;
- : string = "0b11_0111"

Printing Binary Ints in the REPL

# #use "topfind";;
# #require "pp-binary-ints";;
# #install_printer Pp_binary_ints.Int.pp_int;;
# 0;;
- : int = 0b0
# 7;;
- : int = 0b111

You can also add the following to your .ocamlinit file so that integers are always printed using this library.

#use "topfind";;
#require "pp-binary-ints";;
#install_printer Pp_binary_ints.Int.pp_int;;
#install_printer Pp_binary_ints.Int32.pp_int;;
#install_printer Pp_binary_ints.Int64.pp_int;;
#install_printer Pp_binary_ints.Nativeint.pp_int;;

ifazk/pp-binary-ints