erl_tidy(3erl)						     Erlang Module Definition						    erl_tidy(3erl)

NAME

       erl_tidy - Tidies and pretty-prints Erlang source code, removing unused functions, updating obsolete constructs and function calls, etc.

DESCRIPTION

       Tidies and pretty-prints Erlang source code, removing unused functions, updating obsolete constructs and function calls, etc.

       Caveats:  It  is  possible that in some intricate uses of macros, the automatic addition or removal of parentheses around uses or arguments
       could cause the resulting program to be rejected by the compiler; however, we have found no such case in existing code.	Programs  defining
       strange macros can usually not be read by this program, and in those cases, no changes will be made.

       If you really, really want to, you may call it "Inga".

       Disclaimer:  The author accepts no responsibility for errors introduced in code that has been processed by the program. It has been reason-
       ably well tested, but the possibility of errors remains. Keep backups of your original code safely stored, until you  feel  confident  that
       the new, modified code can be trusted.

EXPORTS

       dir() -> ok

	      Equivalent to dir("") .

       dir(Dir) -> ok

	      Equivalent to dir(Dir, []) .

       dir(Directory::filename(), Options::[term()]) -> ok

	      Types  filename() (see module file)

	      Tidies Erlang source files in a directory and its subdirectories.

	      Available options:

		{follow_links, boolean()} :
		  If the value is true , symbolic directory links will be followed. The default value is false .

		{recursive, boolean()} :
		  If the value is true , subdirectories will be visited recursively. The default value is true .

		{regexp, string()} :
		  The  value  denotes  a  regular expression (see module regexp ). Tidying will only be applied to those regular files whose names
		  match this pattern. The default value is ".*\.erl$" , which matches normal Erlang source file names.

		{test, boolean()} :
		  If the value is true , no files will be modified. The default value is false .

		{verbose, boolean()} :
		  If the value is true , progress messages will be output while the program is running, unless the quiet  option  is  true  .  The
		  default value when calling dir/2 is true .

	      See the function file/2 for further options.

	      See also: regexp(3erl) , file/2 .

       file(Name) -> ok

	      Equivalent to file(Name, []) .

       file(Name::filename(), Options::[term()]) -> ok

	      Tidies an Erlang source code file.

	      Available options are:

		{backup_suffix, string()} :
		  Specifies the file name suffix to be used when a backup file is created; the default value is ".bak" (cf. the backups option).

		{backups, boolean()} :
		  If  the  value  is  true  ,  existing files will be renamed before new files are opened for writing. The new names are formed by
		  appending the string given by the backup_suffix option to the original name. The default value is true .

		{dir, filename()} :
		  Specifies the name of the directory in which the output file is to be written. By default, the current directory is used. If the
		  value is an empty string, the current directory is used.

		{outfile, filename()} :
		  Specifies the name of the file (without suffix) to which the resulting source code is to be written. If this option is not spec-
		  ified, the Name argument is used.

		{printer, Function} :

		  * Function = (syntaxTree()) -> string()

		  Specifies a function for prettyprinting Erlang syntax trees. This is used for outputting the resulting  module  definition.  The
		  function  is	assumed  to return formatted text for the given syntax tree, and should raise an exception if an error occurs. The
		  default formatting function calls erl_prettypr:format/2 .

		{test, boolean()} :
		  If the value is true , no files will be modified; this is typically most useful if the verbose  flag	is  enabled,  to  generate
		  reports about the program files without affecting them. The default value is false .

	      See the function module/2 for further options.

	      See also: module/2 , erl_prettypr:format/2 .

       module(Forms) -> syntaxTree()

	      Equivalent to module(Forms, []) .

       module(Forms, Options::[term()]) -> syntaxTree()

	      Types  Forms = syntaxTree() | [syntaxTree()]
		     syntaxTree() (see module erl_syntax)

	      Tidies  a  syntax tree representation of a module definition. The given Forms may be either a single syntax tree of type form_list ,
	      or a list of syntax trees representing "program forms". In either case, Forms must represent a single  complete  module  definition.
	      The returned syntax tree has type form_list and represents a tidied-up version of the same source code.

	      Available options are:

		{auto_export_vars, boolean()} :
		  If the value is true , all matches " {V1, ..., Vn} = E " where E is a case-, if- or receive-expression whose branches all return
		  n-tuples (or explicitly throw exceptions) will be rewritten to bind and export the variables V1 , ..., Vn directly. The  default
		  value is false .

		  For example:

				 {X, Y} = case ... of
					      ... -> {17, foo()};
					      ... -> {42, bar()}
					  end

		  will be rewritten to:

				 case ... of
				     ... -> X = 17, Y = foo(), {X, Y};
				     ... -> X = 42, Y = bar(), {X, Y}
				 end

		{auto_list_comp, boolean()} :
		  If the value is true , calls to lists:map/2 and lists:filter/2 will be rewritten using list comprehensions. The default value is
		  true .

		{file, string()} :
		  Specifies the name of the file from which the source code was taken. This is only used for  generation  of  error  reports.  The
		  default value is the empty string.

		{idem, boolean()} :
		  If  the  value  is  true , all options that affect how the code is modified are set to "no changes". For example, to only update
		  guard tests, and nothing else, use the options [new_guard_tests, idem] . (Recall that options closer to  the	beginning  of  the
		  list have higher precedence.)

		{keep_unused, boolean()} :
		  If the value is true , unused functions will not be removed from the code. The default value is false .

		{new_guard_tests, boolean()} :
		  If  the  value is true , guard tests will be updated to use the new names, e.g. " is_integer(X) " instead of " integer(X) ". The
		  default value is true . See also old_guard_tests .

		{no_imports, boolean()} :
		  If the value is true , all import statements will be removed and calls to imported functions will be expanded to explicit remote
		  calls. The default value is false .

		{old_guard_tests, boolean()} :
		  If  the value is true , guard tests will be changed to use the old names instead of the new ones, e.g. " integer(X) " instead of
		  " is_integer(X) ". The default value is false . This option overrides the new_guard_tests option.

		{quiet, boolean()} :
		  If the value is true , all information messages and warning messages will be suppressed. The default value is false .

		{rename, [{{atom(), atom(), integer()}, {atom(), atom()}}]} :
		  The value is a list of pairs, associating tuples {Module, Name, Arity} with tuples {NewModule, NewName} ,  specifying  renamings
		  of calls to remote functions. By default, the value is the empty list.

		  The  renaming  affects  only	remote	calls  (also  when  disguised by import declarations); local calls within a module are not
		  affected, and no function definitions are renamed. Since the arity cannot change, the new name  is  represented  by  {NewModule,
		  NewName}  only.  Only  calls matching the specified arity will match; multiple entries are necessary for renaming calls to func-
		  tions that have the same module and function name, but different arities.

		  This option can also be used to override the default renaming of calls which use obsolete function names.

		{verbose, boolean()} :
		  If the value is true , progress messages will be output while the program is running, unless the quiet  option  is  true  .  The
		  default value is false .

AUTHORS

       Richard Carlsson <richardc@it.uu.se >

								syntax_tools 1.6.7						    erl_tidy(3erl)