README

erlmacro
========
Just a couple of convenient macros for erlang programmers.

How to use
==========
Just copy files under ./include directory wherever you need.

log.hrl
=======
./test/log.erl shows how TRACE/1, DEBUG/1, INFO/1, WARNING/1 and ERROR/1 macros
work.

$ erlc -I include -o ebin -DDEBUG test/log.erl
$ erl +W w -pa ebin

1> log:showme().

Also compile without the -DDEBUG flag and do the same to find differences.

props_to_record.hrl
===================
Using proplists is a good way to transfer function parameters in erlang.
You can take only some of the parameters in your function in arbitrary order
and ignore others.

person(Props) ->
	Name = proplists:get_value(name, Props, "Default Name"),
	Sex = proplists:get_value(sex, Props, male),
	Age = proplists:get_value(age, Props), % default is undefined
	...
	
You can do the above systematically as,

-include("props_to_record.hrl").

-record(person, {name="Default Name",
                 sex=male,
                 age}).

person(Props) ->
	Person = ?PROPS_TO_RECORD(Props, person),
	% Use Person#person.name and so on...
	...
	
The macro PROPS_TO_RECORD/2 macro converts arbitrary proplists into a
predefined record which is more convenient to use.  Default values in the
record definition is preserved if there is no property of the field name as
the key.  Properties with an unknown key is ignored.