epp

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epp An Erlang Code Preprocessor

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

open(FileName, IncludePath) -> {ok,Epp} | {error, ErrorDescriptor} open(FileName, IncludePath, PredefMacros) -> {ok,Epp} | {error, ErrorDescriptor} Open a file for preprocessing 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 Close the preprocessing of the file associated with Epp Epp = pid() -- handle to the epp server

Closes the preprocessing of a file.

parse_erl_form(Epp) -> {ok, AbsForm} | {eof, Line} | {error, ErrorInfo} Return the next Erlang form from the opened Erlang source file 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} Preprocesse and parse an Erlang source file 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)