19962016 Ericsson AB. All Rights Reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. epp Kenneth Lundin Kenneth Lundin 1 Kenneth Lundin 1997-01-31 B epp.xml
epp An Erlang code preprocessor.

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

The Erlang source file encoding is selected by a comment in one of the first two lines of the source file. The first string matching the regular expression coding\s*[:=]\s*([-a-zA-Z0-9])+ selects the encoding. If the matching string is not a valid encoding, it is ignored. The valid encodings are Latin-1 and UTF-8, where the case of the characters can be chosen freely.

Examples:

%% coding: utf-8
%% For this file we have chosen encoding = Latin-1
%% -*- coding: latin-1 -*-

Handle to the epp server.

Close the preprocessing of the file associated with Epp.

Closes the preprocessing of a file.

Return the default encoding of Erlang source files.

Returns the default encoding of Erlang source files.

Return a string representation of an encoding.

Returns a string representation of an encoding. The string is recognized by read_encoding/1,2, read_encoding_from_binary/1,2, and set_encoding/1,2 as a valid encoding.

Format an error descriptor.

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

Open a file for preprocessing.

Opens a file for preprocessing.

If extra is specified in Options, the return value is {ok, Epp, Extra} instead of {ok, Epp}.

Open a file for preprocessing.

Equivalent to epp:open([{name, FileName}, {includes, IncludePath}]).

Open a file for preprocessing.

Equivalent to epp:open([{name, FileName}, {includes, IncludePath}, {macros, PredefMacros}]).

Return the next Erlang form from the opened Erlang source file.

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

Preprocess and parse an Erlang source file.

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

If extra is specified in Options, the return value is {ok, [Form], Extra} instead of {ok, [Form]}.

Preprocess and parse an Erlang source file.

Equivalent to epp:parse_file(FileName, [{includes, IncludePath}, {macros, PredefMacros}]).

Read the encoding from a file.

Read the encoding from a file. Returns the read encoding, or none if no valid encoding is found.

Option in_comment_only is true by default, which is correct for Erlang source files. If set to false, the encoding string does not necessarily have to occur in a comment.

Read the encoding from a binary.

Read the encoding from a binary. Returns the read encoding, or none if no valid encoding is found.

Option in_comment_only is true by default, which is correct for Erlang source files. If set to false, the encoding string does not necessarily have to occur in a comment.

Read and set the encoding of an I/O device.

Reads the encoding from an I/O device and sets the encoding of the device accordingly. The position of the I/O device referenced by File is not affected. If no valid encoding can be read from the I/O device, the encoding of the I/O device is set to the default encoding.

Returns the read encoding, or none if no valid encoding is found.

Read and set the encoding of an I/O device.

Reads the encoding from an I/O device and sets the encoding of the device accordingly. The position of the I/O device referenced by File is not affected. If no valid encoding can be read from the I/O device, the encoding of the I/O device is set to the encoding specified by Default.

Returns the read encoding, or none if no valid encoding is found.

Error Information

ErrorInfo is the standard ErrorInfo structure that is returned from all I/O modules. The format is as follows:

{ErrorLine, Module, ErrorDescriptor}

A string describing the error is obtained with the following call:

Module:format_error(ErrorDescriptor)
See Also

erl_parse(3)