epp(3erl) [linux man page]

epp(3erl)						     Erlang Module Definition							 epp(3erl)

NAME

       epp - An Erlang Code Preprocessor

DESCRIPTION

       The  Erlang code preprocessor includes functions which are used by compile to preprocess macros and include files before the actual parsing
       takes place.

EXPORTS

       open(FileName, IncludePath) -> {ok,Epp} | {error, ErrorDescriptor}
       open(FileName, IncludePath, PredefMacros) -> {ok,Epp} | {error, ErrorDescriptor}

	      Types  FileName = atom() | string()
		     IncludePath = [DirectoryName]
		     DirectoryName = atom() | string()
		     PredefMacros = [{atom(),term()}]
		     Epp = pid() -- handle to the epp server
		     ErrorDescriptor = term()

	      Opens a file for preprocessing.

       close(Epp) -> ok

	      Types  Epp = pid() -- handle to the epp server

	      Closes the preprocessing of a file.

       parse_erl_form(Epp) -> {ok, AbsForm} | {eof, Line} | {error, ErrorInfo}

	      Types  Epp = pid()
		     AbsForm = term()
		     Line = integer()
		     ErrorInfo = see separate description below.

	      Returns the next Erlang form from the opened Erlang source file. The tuple {eof, Line} is returned at end-of-file.  The  first  form
	      corresponds to an implicit attribute -file(File,1). , where File is the name of the file.

       parse_file(FileName,IncludePath,PredefMacro) -> {ok,[Form]} | {error,OpenError}

	      Types  FileName = atom() | string()
		     IncludePath = [DirectoryName]
		     DirectoryName = atom() | string()
		     PredefMacros = [{atom(),term()}]
		     Form = term() -- same as returned by erl_parse:parse_form

	      Preprocesses and parses an Erlang source file. Note that the tuple {eof, Line} returned at end-of-file is included as a "form".

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)

Ericsson AB							   stdlib 1.17.3							 epp(3erl)

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)