Source Code Formatter

wiki

Why?

• Its a real bind doing it by hand :o)
• Inconsistency of tab sizes. Different authors and editors have different different tab sizes which may vary from the size of 8 space tabs here on the wiki. This works both ways. When you paste code here the tab size may be different and when you copy code from the wiki it may be inconsistent.
• Automatic indentation in your editor may have added tabs into your code (maybe without you even realising!). These may expand to a different size here.
• Its nice when code is a standard width so you dont have to keep resizing your viewing window.
• Homogenous appearance means more consistency for scripts which (hopefully) makes them easier on the eye. The intention being that the wiki looks like a collective effort, rather than the effort of individuals. We are the Lua Wiki Borg! :-)

Disclaimer: You are not forced to use this script!! You may experience problems when pasting code snippets or scripts into the wiki editor because of tabs. This script is here to help you. Hopefully by having a similar source code format this wiki will look consistent and more organised. Please do not start a flame war about what is good and bad formatting. You are free to do as you please.

What the script does

• Removes tab indents and replaces them with spaces.
• Standardises indentation at 2 spaces per indent.
• Checks that line lengths don't exceed 80 characters.

Usage

• Use: lua -f codeformat.lua ...options....
• --file <lua file> - the Lua file to process
• --ts <size> - the size of your tabs eg. --ts 4 (spaces)
• --in <indent size> - number of spaces you use for indentation.
• eg. lua -f codeformat.lua --file myfile.lua --ts 4 --in 4 for files with a tab size of 4 spaces and an indent step of 4 spaces.

This script works with Lua 5.0. (Thanks to whoever updated the library calls from the Lua 4.0 version.)

-- Lua code formatter

-- Removes tabs and checks lines arent too long.

-- Nick Trout

-- $Header: /Tools/build/codefmt.lua 3     16/08/01 20:00 Nick $

-- For Lua 5.0



mytabs = 4 -- spaces (default)

myindent = 4 -- spaces (default)

codetabsize = 8 -- spaces

codeindent = 2 -- spaces per indent

codelinelength = 80 -- characters





usage = 

[[



Usage: lua -f codeformat.lua ...options...



Options are:

--file <lua file>

--ts <spaces>, tabsize: number of spaces in your tabs

--in <spaces>, indent size: number of spaces for each indentation



]]





function process_args()

  -- get args set by user in command line

  local t,i = {},1

  while i<table.getn(arg) do

    local a=arg[i]

    if a=="--file" then

      t.filename,i = arg[i+1],i+2

    elseif a=="--ts" then

      t.mytabsize,i = arg[i+1]+0,i+2

    elseif a=="--in" then

      t.myindent,i = arg[i+1]+0,i+2

    else

      print(usage.."Bad flag: "..a)

      os.exit(-1)

    end

  end

  return t

end



function readfile(f)

  local fh=io.open(f,"rt")

  local t={}

  while 1 do

    local ln=fh:read("*l")

    if ln then table.insert(t,ln) else break end

  end

  fh:close()

  return t

end



-- convert any leading tabs in a given string to spaces.

-- the number of spaces to replace the tab by is given by args.mytabsize

function convertTabsToSpaces(ln)

  local s,e = string.find(ln,"\t+",1)

  if s and s==1 then

    local spc = string.rep(" ",args.mytabsize*(e-s+1))

    ln = spc..string.sub(ln,e+1)

  end

  return ln

end



-- convert any indentation to use the standard indent

function indent(ln)

  local s,e = string.find(ln," +",1)

  if s==1 then

    local indent = (e-s+1)/args.myindent

    ln = string.rep(" ",codeindent*indent)..string.sub(ln,e+1)

  end

  return ln

end

  

function process(lines)

  for li=1,table.getn(lines) do

    local line=lines[li]

    line = convertTabsToSpaces(line)

    line = indent(line)

    -- warn if length too long

    local len=string.len(line)

    if len>codelinelength then

      print("-- ######## Line too long ("..len.." chars) ######## :")

    end

    print(line)

  end

end



args = process_args()

if not args.filename then error(usage.."no Lua file given") end

args.mytabsize = args.mytabsize or mytabs

args.myindent = args.myindent or myindent

process( readfile(args.filename) )