A lua library completes data beautification output, and has no external dependencies.

Install

You can install the library with luarock, like this:

$ luarocks install pprint

Or the file should dropped into a project or a lua lib, then require by it:

pprint = require('pprint')

Also, using the library is very simple. It provides several functions:

• pprint.pprint(obj, indent?, width?, depth?)

  Print the formatted representation of object with color to stream with a trailing newline.

  indent: indent of each level

  width: max col limit

  depth: level limit of recursive

  local test_struct = {
      ['name'] = 'Tom',
      age = 18,
      hobbys = {
          'game',
          ['ball'] = {'football', 'basketball'}
      },
      eat = function(food)
          print('I eat: ' .. food)
      end
  }
  pprint.pprint(test_struct)

  

• pprint.pp(obj, args?)

  Print the formatted representation of object to stream with a trailing newline.

  args: The options of function. Will be transparently transmitted to PrettyPrinter.

• pprint.pformat(obj, indent?, width?, depth?)

  Return the formatted representation of object as a string.

  indent: Number of spaces to indent for each level of nesting.

  width: Attempted maximum number of columns in the output.

  depth: Depth limit, exceeding the limit will be folded.

• pprint.isrecursive(obj)

  Determines whether object requires recursive representation.

  pprint.isrecursive(1) -- false
  pprint.isrecursive({1, 2, 3}) -- true

• pprint.isreadable(obj)

  Determines whether the formatted representation of object is "readable" that can be used to reconstruct the object's value via load().

  pprint.isreadable(1) -- true
  pprint.isreadable({1, 2, 3}) -- true
  pprint.isreadable({
            'tom',
            28,
            say = function ()
                print('hello')
            end
          }) -- false

The pprint library define a class: pprint.PrettyPrinter(args)

-- Create a `PrettyPrinter` instance.
local pp = pprint.PrettyPrinter({...})

The args support some arguments:

• args.indent: integer, Number of spaces to indent for each level of nesting.
• args.width: integer, Attempted maximum number of columns in the output.
• args.depth: integer, Depth limit, exceeding the limit will be folded.
• args:compact: boolean, If true, several items will be combined in one line.
• args:sort_tables: boolean, If true, sort the table by key.
• args.scientific_notation: boolean, If true, will display number with scientific notation.
• args.color: boolean, If true, will format with color escape.

The function provided:

• PrettyPrinter:pprint(obj)
• PrettyPrinter:pformat(obj)
• PrettyPrinter:isrecursive(obj)
• PrettyPrinter:isreadable(obj)

• Pure lua implementation, no external lib dependencies.
• Support color output.
• Work with lua >=5.2