package pp-binary-ints

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.to_string_with ~flags ~min_width converts ints to strings, customizing the output with flags and min_width.
• Int.pp_int is a simple Format module style pretty printer.
• Int.pp_binary_int ~flags ~min_width is a customizable Format module style pretty printer.

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.

Basic use

# #require "pp-binary-ints";;
# module Pp_Bin = Pp_binary_ints.Int;;
# Pp_Bin.to_string 0b110111;;
- : string = "110111"
# Pp_Bin.to_string 0o777;;
- : string = "111111111"
# Pp_Bin.to_string 1234;;
- : string = "10011010010"

Customizing padding and minimum width

# #require "pp-binary-ints";;
# module Pp_Bin = Pp_binary_ints.Int;;
# (* Zero Padding *);;
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ default with padding = Zeros } ~min_width:13 0b110111;;
- : string = "0000000110111"
# (* Default is space padding on the right *);;
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.default ~min_width:13 0b110111;;
- : string = "110111       "
# (* Space padding on the left is also possible *);;
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ default with padding = Left} ~min_width:13 0b110111;;
- : string = "       110111"

Separators and prefixes

# (* Separate every 4 digits with _ *);;
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ default with separators = true } ~min_width:1 0b110111;;
- : string = "11_0111"
# (* Prefix non-zero *);;
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ default with prefix_non_zero = true } ~min_width:1 0b110111;;
- : string = "0b110111"
# (* Prefix non-zero with separators *);;
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ default with prefix_non_zero = true; separators = true } ~min_width:1 0b110111;;
- : string = "0b11_0111"

Zero printing behaviour

We support pretty printing 0 (zero) both how OCaml's Printf woould print it, as well as printing it similar to how we print non zero integers. The default behaviour is to follow Printf's zero printing.

# (* Prefix's are not added to zero by default *);;
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ default with prefix_non_zero = true } ~min_width:1 0;;
- : string = "0"
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ default with prefix_non_zero = true; zero_printing = InheritNonZero } ~min_width:1 0;;
- : string = "0b0"
# (* For Zero padding, separators are not used by default *);;
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ default with padding = Zeros; separators = true } ~min_width:6 0;;
- : string = "000000"
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ default with padding = Zeros; separators = true; zero_printing = InheritNonZero } ~min_width:6 0;;
- : string = "0_0000"
# (* All the above options can be combined *);;
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ padding = Zeros; separators = true; prefix_non_zero = true; zero_printing = InheritNonZero } ~min_width:8 0;;
- : string = "0b0_0000"
# (* The library is careful not to write "0b_" when prefixing, 'b' is always follewd by a digit *);;
# Pp_Bin.to_string_with ~flags:Pp_Bin.Flags.{ padding = Zeros; separators = true; prefix_non_zero = true; zero_printing = InheritNonZero } ~min_width:7 0;;
- : string = "0b00000"