[[PageOutline]]

= !RefactorErl Console Interface =

When running !RefactorErl, you can control the tool via function calls typed into the Erlang shell. !RefactorErl has many features, and is quite a complex system with dozen of functions whose name we do not expect our users to remember. In order to ease and unify the command-level access to all the analysis and refactoring functionality, we have designed a group of Erlang functions that cover the most frequently used features of the tool. The module these functions are located in is called {{{ri}}}, you can use this module to interact easily with the tool. You can add files/directories to the database, run [[SemanticQuery|semantic queries]], create backups, or even do [[RefactoringSteps|transformations]] via this Erlang-level interface.

== Command-line help ==

Help can be acquired in {{{ri}}} with

{{{
#!erlang
ri:help().
}}}

or even shorter as

{{{
#!erlang
ri:h().
}}}

This function lists several topics, on which further help is available by

{{{
#!erlang
ri:h(Topic).
}}}

If you need specific help with a function, simply call it with an {{{_h}}} postfix to the name. For example, help for the function add is available by calling

{{{
#!erlang
ri:add_h()
}}}


== Compiling the tool ==

The tool can be compiled/recompiled by invoking

{{{
#!erlang
ri:build().
}}}

You can also specify build parameters, but this feature is mostly applied through the development, so please find the module documentation for the details. Note that this build function tries to compile the [[NifDB|NIF graph representation]] as well, if these have not been compiled yet. If you want to prevent this, you can use the {{{no_nif}}} build parameter.

== Managing files ==

You can add files to the !RefactorErl database by calling the
add function with either a filename as a string or a module name as an atom.
Note that in the latter case, "ri" defaults to the current working directory
(which you may work around by including a path in your singe-quoted atom).
If you specify a directory instead of a regular filename, then it will be recursively
traversed. You may just as well give a list of atoms or strings to add more files
at once. All of the following example commands would add the same file:

{{{
#!erlang
 cd(dir), ri:add(modname).
 ri:add('dir/modname').
 ri:add(['dir/modname']).
 ri:add("dir/modname.erl").
 ri:add("/current/dir/modname.erl").
}}}

The module displays the progression of loading.
Removing files from the database is similarly easy and also recursive, except
for one difference. You need not restrict yourself to dropping a
module relative to the current directory, but in exchange you must use real module
names that do not contain path delimiters. The following will equally work:

{{{
#!erlang
 ri:drop(modname).
 ri:drop([modname]).
 ri:drop("dir/modname.erl").
 ri:drop("/current/dir/modname.erl").
}}}

Modules can be loaded as applications, but the base of your library has to
be set before:

{{{
#!erlang
ri:addenv(appbase, "path/to/my/applib").
}}}

You can check the already given application base directories:

{{{
#!erlang
ri:envs().
}}}

Let's see an example:

{{{
#!erlang
% Here 'appbase' contains 'usr'.
(refactorerl@localhost)18> ri:envs().
output = original
appbase = "/usr/local/lib/erlang/lib"

(refactorerl@localhost)19> ri:add(usr, synatx_tools).
Application synatx_tools not found under usr
not_found

% 'appbase' contains 'usr', so syntax_tools will be loaded from
% '/usr/local/lib/erlang/lib'
(refactorerl@localhost)20> ri:add(usr, syntax_tools).
Adding: /usr/local/lib/erlang/lib/syntax_tools-1.6.7.1/src
...
}}}

You can also set include directories to your include files using:

{{{
#!erlang
ri:addenv(include, "path/to/my/include").
}}}

It is possible to delete the defined environment variables:

{{{
#!erlang
ri:delenv(include).
}}}

Or you can set an environmental variable to another value:
{{{
#!erlang
ri:setenv(env_name, "path/to/new_value").
}}}


For convenience, both the filenames and the directory names can be given
as atoms as well as strings.
The list of loaded files can be obtained by calling

{{{
#!erlang
ri:ls().
}}}

This call also displays the status of the loaded files (error or no_error).
If the module m is loaded,

{{{
#!erlang
ri:ls(m).
}}}

will give information about the functions, records and macros in the file.
The contents of a file can be listed by

{{{
#!erlang
ri:cat(m).
}}}

Usually, Erlang source files (having the extension
.erl) are loaded into !RefactorErl. In addition, !RefactorErl is also capable of
loading compiled .beam files.

{{{
#!erlang
ri:add("compiled.beam").
}}}

Note that this feature is applicable only to those .beam files that were compiled
with the debug_info option. Also note that the resulting file will be pretty
printed by !RefactorErl.

== Using transformations ==
Transformations can be called using their abbreviated
names, and the list of required parameters. These commands are listed in
[[RefactoringSteps|refactoring functionalities]].
There is another way to call a transormation. This way let the user to
choose: user wants to specify all of arguments or not. There are lots of cases
when the user can not specify all of the required arguments. In this case the
tool can help the user with interactions. The tool ask questions and the user
has to answer it to specify the missing arguments. The interactions also work if
there are problems with the given arguments.

== Manipulating the graph ==
You can reset the database by invoking

{{{
#!erlang
ri:reset().
}}}

This will remove all loaded files. This function should be called if the graph
gets corrupted.
You can add a checkpoint using

{{{
#!erlang
ri:backup().
}}}

If the transformations you have performed are not satisfactory, you can go
back to the previous checkpoint using

{{{
#!erlang
ri:undo().
}}}

If you use [[NifDB|NIF graph database]], then it is little different:[[BR]]
You can create backups with '''ri:backup/0''' or '''ri:backup/1''' and you can load
these backups with '''ri:restore/1'''.
When execute a transformation a backup will be created, which name differs
from the ordinary backups, and the '''ri:undo/0''' function will restore that.

== Inspecting the graph ==
You can draw the semantic representation graph of !RefactorErl by calling

{{{
#!erlang
ri:graph().
}}}

This function produces a .dot file (by default, graph.dot, although this can be
customised), which can be transformed to several visual formats using Graphviz.
One of these transformations is available from !RefactorErl for convenience:

{{{
#!erlang
ri:svg().
}}}

The representation can be altered:

{{{
#!erlang
ri:svg(OutFile, Filter).
}}}

where Filter is one of the following:\\
* '''all''': default, all edges except environmental ones are shown.\\
* '''syn''': only syntactic edges are shown.\\
* '''sem''': only semantic edges are shown.\\
* '''lex''': only lexical edges are shown.\\
* '''all_env''': all edges are shown, no filtering.\\
* '''ctx''': context related edges are shown.\\
* '''not_lex''': all edges except lexical ones are shown.\\
* '''dataflow''': dataflow related edges are shown.\\
* '''a list of the above''': shows the union of the designated subgraphs.\\

== Using queries ==
Queries can be invoked by either

{{{
#!erlang
ri:q(Query).
}}}

or

{{{
#!erlang
ri:q(Module, Regexp, Query).
}}}

The former is applicable when a query starts generally, such as

{{{
#!erlang
ri:q("mods.funs.name").
}}}

For those queries that begin from a selected position (these queries start
with "@" when used from Emacs), the second variant is required. As the console
cannot mark a position, the first and the second component indicate the starting
point for the query. The following example shows how to get all the variables
used in the body of the function '''f/2''' from the module '''m'''.

{{{
#!erlang
ri:q(m, "f\\(X, Y\\)", "@fun.var").
}}}

Additional options can be given to a [[SemanticQuery|semantic query]] in a proplist as the last
argument. The following arguments are currently recognized:\\
* '''{out,!FileName}''': write the textual output of a query to a file.\\
* '''linenum''': prepends match sites with file and line number information.\\
similar to '''grep -n'''.
The following example outputs all defined functions with line numbers to a
file named result.txt.

{{{
#!erlang
ri:q("mods.funs",[linenum,{out,"result.txt"}]).
}}}

There is a [[SemanticQuery|semantic queries]] page, where you can learn more about this topic.

== Dependency analysis ==

The two interface functions are:

1. For drawing:
{{{#!erlang
ri:draw_dep/1
}}}
2. For printing the result to stdout:
{{{#!erlang
ri:print_dep/1
}}}

=== Options ===

The parameter of the interface functions is a proplist setting the options of the analysis. The available options are:

 * {{{level (mod | func)}}}
    The level of the dependency query (module or function).
 * {{{type (all | cycles)}}}
    Whether the investigation should be done on the whole graph, or just on the cyclic part (if exists). When printing out the cycles, type {{{all}}} returns graph nodes, while {{{cycles}}} returns names.
 * {{{otp (true | false)}}}
    Whether Erlang/OTP standard modules should be included in the analysis or not.
 * {{{gnode}}}
    List of entity or entities that should be the starting point of the analysis. Especially at function level, the list is compulsory when the functions are identified by their module, name, arity.
 * exception
    List of entities excluded from the analysis.
 * leaves
    List of those entities which should be included in the analysis, but their children should not (and consequently the children become exceptions).
 * {{{dot}}}
    The file path of the generated {{{.dot}}} graph description. Unless it is a non-existing absolute path, the graph will be placed into the {{{./dep_files}}} directory. This option is only available when using {{{draw_dep}}}.

You can specify entities either with graph nodes (such as {{{{'$gn', func, 123}}}}) or with their identifier. Modules can be specified with their names as atoms (e.g. 'mnesia'), while functions are specified by their MFA descriptor as a string (e.g. "io:format/2")

=== Examples for listing results ===

* Checking for cycles in module level.
{{{#!erlang
ri:print_dep([{level, mod}, {type, all}]).
}}}
  

* Checking for cycles in function level, and printing out names of the functions (Module:Function/Arity).
{{{#!erlang
ri:print_dep([{level, func}, {type, cycles}]).
}}}
{{{#!erlang
  [['foo:fv4/1','foo:fv4/1'],
  ['test3:p/1','test:fv6/1','test3:p/1'],
  ['cycle4:f4/1','cycle3:f3/1','cycle4:f4/1'],
  ['cycle2:fv2/1','cycle1:fv1/0','cycle2:fv2/1'],
  ['test:fv5/1','test:fv4/2','test:fv5/1'],
  ['cycle4:f5/1','cycle3:f6/1','cycle4:f5/1']]
}}}


* Checking for cycles in function level, and printing out the graph nodes of the functions.
{{{#!erlang
ri:print_dep([{level, func}, {type, all}]).
}}}
{{{#!erlang
  {"6 cycle(s)",
  {[[{'$gn',func,28},{'$gn',func,28}], 
  [{'$gn',func,29},{'$gn',func,37},{'$gn',func,29}],
  [{'$gn',func,7},{'$gn',func,9},{'$gn',func,7}],
  [{'$gn',func,2},{'$gn',func,1},{'$gn',func,2}],
  [{'$gn',func,36},{'$gn',func,35},{'$gn',func,36}],
  [{'$gn',func,8},{'$gn',func,6},{'$gn',func,8}]]}
}}}

* Checking for cycles in module level from a given node
{{{#!erlang
ri:print_dep([{level, mod}, {gnode, {'$gn', module, 24}}]). 
}}}
{{{#!erlang
  {true,[[{'$gn',module,24},
          {'$gn',module,25},
          {'$gn',module,24}]]}
}}}

* Checking for cycles in function level from a node given with its identifier
{{{#!erlang
ri:print_dep([{level, func}, {gnode, ["cycle4:f5/1"]}]).
}}}

== Server management command list ==

Here's the list of supported server management commands:\\
* '''add(FDML)''': add a module, file, directory or a list of these to the database. \\
* '''drop(FDML)''': drop a module from the database. \\
* '''ls()''': list files that are in the database. \\
* '''backup()''': update the backup (checkpoint). \\
* '''undo()''': undo the transformation (rollback, only one step). \\
* '''clean()''': clean backups (delete all checkpoints). \\
* '''reset()''': reset the database to an empty state, but valid schema. \\
* '''graph(Target)''': assume no options and call one of the next two. \\
* '''graph(Atom,Options)''': assume ".dot" extension and call the one below. \\
* '''graph(File,Options)''': draw the graph with the given options. \\
* '''svg()''': draw the graph to graph.svg and call Graphviz. \\
* '''svg(File)''' \\
* '''svg(File, Options)''' \\
The additional/modied commands, that you can use, if you use the [[NifDB|NIF database engine]]:\\
* '''backup()''': creates a backup. \\
* '''backup(!CommitLog)''': creates a backup as '''ri:backup/0''', but here the user can attach a commit log to the backup file. \\
* '''ls_backups()''': returns a lists of backups, that has been created before with '''ri:backup/0''' or '''ri:backup/1'''. \\
* '''backup_info(Backup)''': returns information about the given backup. \\
* '''restore(Backup)''': restores the given backup. \\
* '''create_graph(Name)''': creates a graph with the given name. \\
* '''rename_graph(!OldName, !NewName)''': renames a graph that has the given !OldName, with the given !NewName. \\
* '''ls_graphs()''': returns a list of the created graphs. \\
* '''actual_graph()''': returns the actual graph's name. \\
* '''load_graph(Name)''': loads the given graph. \\
* '''delete_graph(Name)''': removes the given graph. \\
* '''delete_all_graphs()''': removes all graphs. \\