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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 reasonably 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.

DATA TYPES

         filename() = file:filename():

         syntaxTree() = erl_syntax:syntaxTree():

           An abstract syntax tree. See the erl_syntax module for details.

EXPORTS

       dir() -> ok

              Equivalent to dir("").

       dir(Dir) -> ok

              Equivalent to dir(Dir, []).

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

              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 re). 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: re(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 specified, the  Name  argument  is
                  used.

                {printer, Function}:

                  * Function = (syntaxTree(), [term()]) -> 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.

                {stdout, boolean()}:
                  If the value is true, instead of the file being written  to  disk  it  will  be
                  printed to stdout. 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()]

              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
                  functions 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 <carlsson.richard@gmail.com>

                                        syntax_tools 2.1.4                         erl_tidy(3erl)