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.

Functions

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

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

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

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

Closes the preprocessing of a file.

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

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}

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)

epp