erl_lint(3erl) [linux man page]

erl_lint(3erl)						     Erlang Module Definition						    erl_lint(3erl)

NAME

       erl_lint - The Erlang Code Linter

DESCRIPTION

       This  module  is  used  to check Erlang code for illegal syntax and other bugs. It also warns against coding practices which are not recom-
       mended.

       The errors detected include:

	 * redefined and undefined functions

	 * unbound and unsafe variables

	 * illegal record usage.

       Warnings include:

	 * unused functions and imports

	 * unused variables

	 * variables imported into matches

	 * variables exported from if / case / receive

	 * variables shadowed in lambdas and list comprehensions.

       Some of the warnings are optional, and can be turned on by giving the appropriate option, described below.

       The functions in this module are invoked automatically by the Erlang compiler and there is no reason to invoke these  functions	separately
       unless you have written your own Erlang compiler.

EXPORTS

       module(AbsForms) -> {ok,Warnings} | {error,Errors,Warnings}
       module(AbsForms, FileName) -> {ok,Warnings} | {error,Errors,Warnings}
       module(AbsForms, FileName, CompileOptions) -> {ok,Warnings} | {error,Errors,Warnings}

	      Types  AbsForms = [term()]
		     FileName = FileName2 = atom() | string()
		     Warnings = Errors = [{Filename2,[ErrorInfo]}]
		     ErrorInfo = see separate description below.
		     CompileOptions = [term()]

	      This function checks all the forms in a module for errors. It returns:

		{ok,Warnings} :
		  There were no errors in the module.

		{error,Errors,Warnings} :
		  There were errors in the module.

	      Since  this module is of interest only to the maintainers of the compiler, and to avoid having the same description in two places to
	      avoid the usual maintenance nightmare, the elements of Options that control the warnings are only described in compile(3erl) .

	      The AbsForms of a module which comes from a file that is read through epp , the Erlang pre-processor, can come from many files. This
	      means that any references to errors must include the file name (see epp(3erl) , or parser erl_parse(3erl) ). The warnings and errors
	      returned have the following format:

		  [{FileName2,[ErrorInfo]}]

	      The errors and warnings are listed in the order in which they are encountered in the forms. This means that the errors from one file
	      may be split into different entries in the list of errors.

       is_guard_test(Expr) -> bool()

	      Types  Expr = term()

	      This  function  tests  if  Expr  is  a  legal  guard test. Expr is an Erlang term representing the abstract form for the expression.
	      erl_parse:parse_exprs(Tokens) can be used to generate a list of Expr .

       format_error(ErrorDescriptor) -> Chars

	      Types  ErrorDescriptor = errordesc()
		     Chars = [char() | Chars]

	      Takes an ErrorDescriptor and returns a string which describes the error or warning. This function is usually called implicitly  when
	      processing an ErrorInfo structure (see below).

ERROR INFORMATION

       The ErrorInfo mentioned above is the standard ErrorInfo structure which is returned from all IO modules. It has the following format:

	   {ErrorLine, Module, ErrorDescriptor}

       A string which describes the error is obtained with the following call:

	   Module:format_error(ErrorDescriptor)

SEE ALSO

       erl_parse(3erl) , epp(3erl)

Ericsson AB							   stdlib 1.17.3						    erl_lint(3erl)

epp_dodger(3erl)					     Erlang Module Definition						  epp_dodger(3erl)

NAME

       epp_dodger - epp_dodger - bypasses the Erlang preprocessor.

DESCRIPTION

       epp_dodger - bypasses the Erlang preprocessor.

       This module tokenises and parses most Erlang source code without expanding preprocessor directives and macro applications, as long as these
       are syntactically "well-behaved". Because the normal parse trees of the erl_parse module cannot represent these things (normally, they  are
       expanded  by  the Erlang preprocessor epp(3erl) before the parser sees them), an extended syntax tree is created, using the erl_syntax mod-
       ule.

DATA TYPES

	 errorinfo() = {ErrorLine::integer(), Module::atom(), Descriptor::term()} :

	   This is a so-called Erlang I/O ErrorInfo structure; see the io(3erl) module for details.

EXPORTS

       parse(Dev::IODevice) -> {ok, Forms} | {error, errorinfo()}

	      Equivalent to parse(IODevice, 1) .

       parse(Dev::IODevice, L::StartLine) -> {ok, Forms} | {error, errorinfo()}

	      Types  IODevice = pid()
		     StartLine = integer()
		     Forms = [syntaxTree() (see module erl_syntax)]

	      Equivalent to parse(IODevice, StartLine, []) .

	      See also: parse/1 .

       parse(Dev::IODevice, L0::StartLine, Options) -> {ok, Forms} | {error, errorinfo()}

	      Types  IODevice = pid()
		     StartLine = integer()
		     Options = [term()]
		     Forms = [syntaxTree() (see module erl_syntax)]

	      Reads and parses program text from an I/O stream. Characters are read from IODevice until end-of-file; apart from this,  the  behav-
	      iour is the same as for parse_file/2 . StartLine is the initial line number, which should be a positive integer.

	      See also: parse/2 , parse_file/2 , parse_form/2 , quick_parse/3 .

       parse_file(File) -> {ok, Forms} | {error, errorinfo()}

	      Types  File = filename() (see module file)
		     Forms = [syntaxTree() (see module erl_syntax)]

	      Equivalent to parse_file(File, []) .

       parse_file(File, Options) -> {ok, Forms} | {error, errorinfo()}

	      Types  File = filename() (see module file)
		     Options = [term()]
		     Forms = [syntaxTree() (see module erl_syntax)]

	      Reads  and  parses  a  file. If successful, {ok, Forms} is returned, where Forms is a list of abstract syntax trees representing the
	      "program forms" of the file (cf. erl_syntax:is_form/1 ). Otherwise, {error, errorinfo()} is returned, typically if  the  file  could
	      not  be  opened.	Note  that parse errors show up as error markers in the returned list of forms; they do not cause this function to
	      fail or return {error, errorinfo()} .

	      Options:

		{no_fail, boolean()} :
		  If true , this makes epp_dodger replace any program forms that could not be  parsed  with  nodes  of	type  text  (see  erl_syn-
		  tax:text/1 ), representing the raw token sequence of the form, instead of reporting a parse error. The default value is false .

		{clever, boolean()} :
		  If  set to true , this makes epp_dodger try to repair the source code as it seems fit, in certain cases where parsing would oth-
		  erwise fail. Currently, it inserts ++ -operators between string literals and	macros	where  it  looks  like	concatenation  was
		  intended. The default value is false .

	      See also: parse/2 , quick_parse_file/1 , erl_syntax:is_form/1 .

       parse_form(Dev::IODevice, L0::StartLine) -> {ok, Form, LineNo} | {eof, LineNo} | {error, errorinfo(), LineNo}

	      Types  IODevice = pid()
		     StartLine = integer()
		     Form = syntaxTree() (see module erl_syntax)
		     LineNo = integer()

	      Equivalent to parse_form(IODevice, StartLine, []) .

	      See also: quick_parse_form/2 .

       parse_form(Dev::IODevice, L0::StartLine, Options) -> {ok, Form, LineNo} | {eof, LineNo} | {error, errorinfo(), LineNo}

	      Types  IODevice = pid()
		     StartLine = integer()
		     Options = [term()]
		     Form = syntaxTree() (see module erl_syntax)
		     LineNo = integer()

	      Reads and parses a single program form from an I/O stream. Characters are read from IODevice until an end-of-form marker is found (a
	      period character followed by whitespace), or until end-of-file; apart from this, the behaviour is  similar  to  that  of	parse/3  ,
	      except  that  the  return  values also contain the final line number given that StartLine is the initial line number, and that {eof,
	      LineNo} may be returned.

	      See also: parse/3 , parse_form/2 , quick_parse_form/3 .

       quick_parse(Dev::IODevice) -> {ok, Forms} | {error, errorinfo()}

	      Equivalent to quick_parse(IODevice, 1) .

       quick_parse(Dev::IODevice, L::StartLine) -> {ok, Forms} | {error, errorinfo()}

	      Types  IODevice = pid()
		     StartLine = integer()
		     Forms = [syntaxTree() (see module erl_syntax)]

	      Equivalent to quick_parse(IODevice, StartLine, []) .

	      See also: quick_parse/1 .

       quick_parse(Dev::IODevice, L0::StartLine, Options) -> {ok, Forms} | {error, errorinfo()}

	      Types  IODevice = pid()
		     StartLine = integer()
		     Options = [term()]
		     Forms = [syntaxTree() (see module erl_syntax)]

	      Similar to parse/3 , but does a more quick-and-dirty processing of the code. See quick_parse_file/2 for details.

	      See also: parse/3 , quick_parse/2 , quick_parse_file/2 , quick_parse_form/2 .

       quick_parse_file(File) -> {ok, Forms} | {error, errorinfo()}

	      Types  File = filename() (see module file)
		     Forms = [syntaxTree() (see module erl_syntax)]

	      Equivalent to quick_parse_file(File, []) .

       quick_parse_file(File, Options) -> {ok, Forms} | {error, errorinfo()}

	      Types  File = filename() (see module file)
		     Options = [term()]
		     Forms = [syntaxTree() (see module erl_syntax)]

	      Similar to parse_file/2 , but does a more quick-and-dirty processing of the code. Macro definitions and  other  preprocessor  direc-
	      tives  are  discarded,  and  all	macro calls are replaced with atoms. This is useful when only the main structure of the code is of
	      interest, and not the details. Furthermore, the quick-parse method can usually handle more strange cases than the normal, more exact
	      parsing.

	      Options: see parse_file/2 . Note however that for quick_parse_file/2 , the option no_fail is true by default.

	      See also: parse_file/2 , quick_parse/2 .

       quick_parse_form(Dev::IODevice, L0::StartLine) -> {ok, Form, LineNo} | {eof, LineNo} | {error, errorinfo(), LineNo}

	      Types  IODevice = pid()
		     StartLine = integer()
		     Form = syntaxTree() (see module erl_syntax) | none
		     LineNo = integer()

	      Equivalent to quick_parse_form(IODevice, StartLine, []) .

	      See also: parse_form/2 .

       quick_parse_form(Dev::IODevice, L0::StartLine, Options) -> {ok, Form, LineNo} | {eof, LineNo} | {error, errorinfo(), LineNo}

	      Types  IODevice = pid()
		     StartLine = integer()
		     Options = [term()]
		     Form = syntaxTree() (see module erl_syntax)
		     LineNo = integer()

	      Similar to parse_form/3 , but does a more quick-and-dirty processing of the code. See quick_parse_file/2 for details.

	      See also: parse/3 , parse_form/3 , quick_parse_form/2 .

       tokens_to_string(Tokens::[term()]) -> string()

	      Generates a string corresponding to the given token sequence. The string can be re-tokenized to yield the same token list again.

AUTHORS

       Richard Carlsson <richardc@it.uu.se >

								syntax_tools 1.6.7						  epp_dodger(3erl)