Browse files

GPL v3 license added.

  • Loading branch information...
1 parent fedfa17 commit 0ead1f2c95744151b146d7bcaaed1db004467234 @ivkosh committed Feb 23, 2011
Showing with 744 additions and 21 deletions.
  1. +674 −0 COPYING
  2. +19 −7
  3. +1 −1 src/
  4. +50 −13 src/rdbl.erl
@@ -0,0 +1,674 @@
+ Version 3, 29 June 2007
+ Copyright (C) 2007 Free Software Foundation, Inc. <>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+ Preamble
+ The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+ The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works. By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users. We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors. You can apply it to
+your programs, too.
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+ To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights. Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
+ For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received. You must make sure that they, too, receive
+or can get the source code. And you must show them these terms so they
+know their rights.
+ Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+ For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software. For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+ Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so. This is fundamentally incompatible with the aim of
+protecting users' freedom to change the software. The systematic
+pattern of such abuse occurs in the area of products for individuals to
+use, which is precisely where it is most unacceptable. Therefore, we
+have designed this version of the GPL to prohibit the practice for those
+products. If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
+of the GPL, as needed to protect the freedom of users.
+ Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
+software on general-purpose computers, but in those that do, we wish to
+avoid the special danger that patents applied to a free program could
+make it effectively proprietary. To prevent this, the GPL assures that
+patents cannot be used to render the program non-free.
+ The precise terms and conditions for copying, distribution and
+modification follow.
+ 0. Definitions.
+ "This License" refers to version 3 of the GNU General Public License.
+ "Copyright" also means copyright-like laws that apply to other kinds of
+works, such as semiconductor masks.
+ "The Program" refers to any copyrightable work licensed under this
+License. Each licensee is addressed as "you". "Licensees" and
+"recipients" may be individuals or organizations.
+ To "modify" a work means to copy from or adapt all or part of the work
+in a fashion requiring copyright permission, other than the making of an
+exact copy. The resulting work is called a "modified version" of the
+earlier work or a work "based on" the earlier work.
+ A "covered work" means either the unmodified Program or a work based
+on the Program.
+ To "propagate" a work means to do anything with it that, without
+permission, would make you directly or secondarily liable for
+infringement under applicable copyright law, except executing it on a
+computer or modifying a private copy. Propagation includes copying,
+distribution (with or without modification), making available to the
+public, and in some countries other activities as well.
+ To "convey" a work means any kind of propagation that enables other
+parties to make or receive copies. Mere interaction with a user through
+a computer network, with no transfer of a copy, is not conveying.
+ An interactive user interface displays "Appropriate Legal Notices"
+to the extent that it includes a convenient and prominently visible
+feature that (1) displays an appropriate copyright notice, and (2)
+tells the user that there is no warranty for the work (except to the
+extent that warranties are provided), that licensees may convey the
+work under this License, and how to view a copy of this License. If
+the interface presents a list of user commands or options, such as a
+menu, a prominent item in the list meets this criterion.
+ 1. Source Code.
+ The "source code" for a work means the preferred form of the work
+for making modifications to it. "Object code" means any non-source
+form of a work.
+ A "Standard Interface" means an interface that either is an official
+standard defined by a recognized standards body, or, in the case of
+interfaces specified for a particular programming language, one that
+is widely used among developers working in that language.
+ The "System Libraries" of an executable work include anything, other
+than the work as a whole, that (a) is included in the normal form of
+packaging a Major Component, but which is not part of that Major
+Component, and (b) serves only to enable use of the work with that
+Major Component, or to implement a Standard Interface for which an
+implementation is available to the public in source code form. A
+"Major Component", in this context, means a major essential component
+(kernel, window system, and so on) of the specific operating system
+(if any) on which the executable work runs, or a compiler used to
+produce the work, or an object code interpreter used to run it.
+ The "Corresponding Source" for a work in object code form means all
+the source code needed to generate, install, and (for an executable
+work) run the object code and to modify the work, including scripts to
+control those activities. However, it does not include the work's
+System Libraries, or general-purpose tools or generally available free
+programs which are used unmodified in performing those activities but
+which are not part of the work. For example, Corresponding Source
+includes interface definition files associated with source files for
+the work, and the source code for shared libraries and dynamically
+linked subprograms that the work is specifically designed to require,
+such as by intimate data communication or control flow between those
+subprograms and other parts of the work.
+ The Corresponding Source need not include anything that users
+can regenerate automatically from other parts of the Corresponding
+ The Corresponding Source for a work in source code form is that
+same work.
+ 2. Basic Permissions.
+ All rights granted under this License are granted for the term of
+copyright on the Program, and are irrevocable provided the stated
+conditions are met. This License explicitly affirms your unlimited
+permission to run the unmodified Program. The output from running a
+covered work is covered by this License only if the output, given its
+content, constitutes a covered work. This License acknowledges your
+rights of fair use or other equivalent, as provided by copyright law.
+ You may make, run and propagate covered works that you do not
+convey, without conditions so long as your license otherwise remains
+in force. You may convey covered works to others for the sole purpose
+of having them make modifications exclusively for you, or provide you
+with facilities for running those works, provided that you comply with
+the terms of this License in conveying all material for which you do
+not control copyright. Those thus making or running the covered works
+for you must do so exclusively on your behalf, under your direction
+and control, on terms that prohibit them from making any copies of
+your copyrighted material outside their relationship with you.
+ Conveying under any other circumstances is permitted solely under
+the conditions stated below. Sublicensing is not allowed; section 10
+makes it unnecessary.
+ 3. Protecting Users' Legal Rights From Anti-Circumvention Law.
+ No covered work shall be deemed part of an effective technological
+measure under any applicable law fulfilling obligations under article
+11 of the WIPO copyright treaty adopted on 20 December 1996, or
+similar laws prohibiting or restricting circumvention of such
+ When you convey a covered work, you waive any legal power to forbid
+circumvention of technological measures to the extent such circumvention
+is effected by exercising rights under this License with respect to
+the covered work, and you disclaim any intention to limit operation or
+modification of the work as a means of enforcing, against the work's
+users, your or third parties' legal rights to forbid circumvention of
+technological measures.
+ 4. Conveying Verbatim Copies.
+ You may convey verbatim copies of the Program's source code as you
+receive it, in any medium, provided that you conspicuously and
+appropriately publish on each copy an appropriate copyright notice;
+keep intact all notices stating that this License and any
+non-permissive terms added in accord with section 7 apply to the code;
+keep intact all notices of the absence of any warranty; and give all
+recipients a copy of this License along with the Program.
+ You may charge any price or no price for each copy that you convey,
+and you may offer support or warranty protection for a fee.
+ 5. Conveying Modified Source Versions.
+ You may convey a work based on the Program, or the modifications to
+produce it from the Program, in the form of source code under the
+terms of section 4, provided that you also meet all of these conditions:
+ a) The work must carry prominent notices stating that you modified
+ it, and giving a relevant date.
+ b) The work must carry prominent notices stating that it is
+ released under this License and any conditions added under section
+ 7. This requirement modifies the requirement in section 4 to
+ "keep intact all notices".
+ c) You must license the entire work, as a whole, under this
+ License to anyone who comes into possession of a copy. This
+ License will therefore apply, along with any applicable section 7
+ additional terms, to the whole of the work, and all its parts,
+ regardless of how they are packaged. This License gives no
+ permission to license the work in any other way, but it does not
+ invalidate such permission if you have separately received it.
+ d) If the work has interactive user interfaces, each must display
+ Appropriate Legal Notices; however, if the Program has interactive
+ interfaces that do not display Appropriate Legal Notices, your
+ work need not make them do so.
+ A compilation of a covered work with other separate and independent
+works, which are not by their nature extensions of the covered work,
+and which are not combined with it such as to form a larger program,
+in or on a volume of a storage or distribution medium, is called an
+"aggregate" if the compilation and its resulting copyright are not
+used to limit the access or legal rights of the compilation's users
+beyond what the individual works permit. Inclusion of a covered work
+in an aggregate does not cause this License to apply to the other
+parts of the aggregate.
+ 6. Conveying Non-Source Forms.
+ You may convey a covered work in object code form under the terms
+of sections 4 and 5, provided that you also convey the
+machine-readable Corresponding Source under the terms of this License,
+in one of these ways:
+ a) Convey the object code in, or embodied in, a physical product
+ (including a physical distribution medium), accompanied by the
+ Corresponding Source fixed on a durable physical medium
+ customarily used for software interchange.
+ b) Convey the object code in, or embodied in, a physical product
+ (including a physical distribution medium), accompanied by a
+ written offer, valid for at least three years and valid for as
+ long as you offer spare parts or customer support for that product
+ model, to give anyone who possesses the object code either (1) a
+ copy of the Corresponding Source for all the software in the
+ product that is covered by this License, on a durable physical
+ medium customarily used for software interchange, for a price no
+ more than your reasonable cost of physically performing this
+ conveying of source, or (2) access to copy the
+ Corresponding Source from a network server at no charge.
+ c) Convey individual copies of the object code with a copy of the
+ written offer to provide the Corresponding Source. This
+ alternative is allowed only occasionally and noncommercially, and
+ only if you received the object code with such an offer, in accord
+ with subsection 6b.
+ d) Convey the object code by offering access from a designated
+ place (gratis or for a charge), and offer equivalent access to the
+ Corresponding Source in the same way through the same place at no
+ further charge. You need not require recipients to copy the
+ Corresponding Source along with the object code. If the place to
+ copy the object code is a network server, the Corresponding Source
+ may be on a different server (operated by you or a third party)
+ that supports equivalent copying facilities, provided you maintain
+ clear directions next to the object code saying where to find the
+ Corresponding Source. Regardless of what server hosts the
+ Corresponding Source, you remain obligated to ensure that it is
+ available for as long as needed to satisfy these requirements.
+ e) Convey the object code using peer-to-peer transmission, provided
+ you inform other peers where the object code and Corresponding
+ Source of the work are being offered to the general public at no
+ charge under subsection 6d.
+ A separable portion of the object code, whose source code is excluded
+from the Corresponding Source as a System Library, need not be
+included in conveying the object code work.
+ A "User Product" is either (1) a "consumer product", which means any
+tangible personal property which is normally used for personal, family,
+or household purposes, or (2) anything designed or sold for incorporation
+into a dwelling. In determining whether a product is a consumer product,
+doubtful cases shall be resolved in favor of coverage. For a particular
+product received by a particular user, "normally used" refers to a
+typical or common use of that class of product, regardless of the status
+of the particular user or of the way in which the particular user
+actually uses, or expects or is expected to use, the product. A product
+is a consumer product regardless of whether the product has substantial
+commercial, industrial or non-consumer uses, unless such uses represent
+the only significant mode of use of the product.
+ "Installation Information" for a User Product means any methods,
+procedures, authorization keys, or other information required to install
+and execute modified versions of a covered work in that User Product from
+a modified version of its Corresponding Source. The information must
+suffice to ensure that the continued functioning of the modified object
+code is in no case prevented or interfered with solely because
+modification has been made.
+ If you convey an object code work under this section in, or with, or
+specifically for use in, a User Product, and the conveying occurs as
+part of a transaction in which the right of possession and use of the
+User Product is transferred to the recipient in perpetuity or for a
+fixed term (regardless of how the transaction is characterized), the
+Corresponding Source conveyed under this section must be accompanied
+by the Installation Information. But this requirement does not apply
+if neither you nor any third party retains the ability to install
+modified object code on the User Product (for example, the work has
+been installed in ROM).
+ The requirement to provide Installation Information does not include a
+requirement to continue to provide support service, warranty, or updates
+for a work that has been modified or installed by the recipient, or for
+the User Product in which it has been modified or installed. Access to a
+network may be denied when the modification itself materially and
+adversely affects the operation of the network or violates the rules and
+protocols for communication across the network.
+ Corresponding Source conveyed, and Installation Information provided,
+in accord with this section must be in a format that is publicly
+documented (and with an implementation available to the public in
+source code form), and must require no special password or key for
+unpacking, reading or copying.
+ 7. Additional Terms.
+ "Additional permissions" are terms that supplement the terms of this
+License by making exceptions from one or more of its conditions.
+Additional permissions that are applicable to the entire Program shall
+be treated as though they were included in this License, to the extent
+that they are valid under applicable law. If additional permissions
+apply only to part of the Program, that part may be used separately
+under those permissions, but the entire Program remains governed by
+this License without regard to the additional permissions.
+ When you convey a copy of a covered work, you may at your option
+remove any additional permissions from that copy, or from any part of
+it. (Additional permissions may be written to require their own
+removal in certain cases when you modify the work.) You may place
+additional permissions on material, added by you to a covered work,
+for which you have or can give appropriate copyright permission.
+ Notwithstanding any other provision of this License, for material you
+add to a covered work, you may (if authorized by the copyright holders of
+that material) supplement the terms of this License with terms:
+ a) Disclaiming warranty or limiting liability differently from the
+ terms of sections 15 and 16 of this License; or
+ b) Requiring preservation of specified reasonable legal notices or
+ author attributions in that material or in the Appropriate Legal
+ Notices displayed by works containing it; or
+ c) Prohibiting misrepresentation of the origin of that material, or
+ requiring that modified versions of such material be marked in
+ reasonable ways as different from the original version; or
+ d) Limiting the use for publicity purposes of names of licensors or
+ authors of the material; or
+ e) Declining to grant rights under trademark law for use of some
+ trade names, trademarks, or service marks; or
+ f) Requiring indemnification of licensors and authors of that
+ material by anyone who conveys the material (or modified versions of
+ it) with contractual assumptions of liability to the recipient, for
+ any liability that these contractual assumptions directly impose on
+ those licensors and authors.
+ All other non-permissive additional terms are considered "further
+restrictions" within the meaning of section 10. If the Program as you
+received it, or any part of it, contains a notice stating that it is
+governed by this License along with a term that is a further
+restriction, you may remove that term. If a license document contains
+a further restriction but permits relicensing or conveying under this
+License, you may add to a covered work material governed by the terms
+of that license document, provided that the further restriction does
+not survive such relicensing or conveying.
+ If you add terms to a covered work in accord with this section, you
+must place, in the relevant source files, a statement of the
+additional terms that apply to those files, or a notice indicating
+where to find the applicable terms.
+ Additional terms, permissive or non-permissive, may be stated in the
+form of a separately written license, or stated as exceptions;
+the above requirements apply either way.
+ 8. Termination.
+ You may not propagate or modify a covered work except as expressly
+provided under this License. Any attempt otherwise to propagate or
+modify it is void, and will automatically terminate your rights under
+this License (including any patent licenses granted under the third
+paragraph of section 11).
+ However, if you cease all violation of this License, then your
+license from a particular copyright holder is reinstated (a)
+provisionally, unless and until the copyright holder explicitly and
+finally terminates your license, and (b) permanently, if the copyright
+holder fails to notify you of the violation by some reasonable means
+prior to 60 days after the cessation.
+ Moreover, your license from a particular copyright holder is
+reinstated permanently if the copyright holder notifies you of the
+violation by some reasonable means, this is the first time you have
+received notice of violation of this License (for any work) from that
+copyright holder, and you cure the violation prior to 30 days after
+your receipt of the notice.
+ Termination of your rights under this section does not terminate the
+licenses of parties who have received copies or rights from you under
+this License. If your rights have been terminated and not permanently
+reinstated, you do not qualify to receive new licenses for the same
+material under section 10.
+ 9. Acceptance Not Required for Having Copies.
+ You are not required to accept this License in order to receive or
+run a copy of the Program. Ancillary propagation of a covered work
+occurring solely as a consequence of using peer-to-peer transmission
+to receive a copy likewise does not require acceptance. However,
+nothing other than this License grants you permission to propagate or
+modify any covered work. These actions infringe copyright if you do
+not accept this License. Therefore, by modifying or propagating a
+covered work, you indicate your acceptance of this License to do so.
+ 10. Automatic Licensing of Downstream Recipients.
+ Each time you convey a covered work, the recipient automatically
+receives a license from the original licensors, to run, modify and
+propagate that work, subject to this License. You are not responsible
+for enforcing compliance by third parties with this License.
+ An "entity transaction" is a transaction transferring control of an
+organization, or substantially all assets of one, or subdividing an
+organization, or merging organizations. If propagation of a covered
+work results from an entity transaction, each party to that
+transaction who receives a copy of the work also receives whatever
+licenses to the work the party's predecessor in interest had or could
+give under the previous paragraph, plus a right to possession of the
+Corresponding Source of the work from the predecessor in interest, if
+the predecessor has it or can get it with reasonable efforts.
+ You may not impose any further restrictions on the exercise of the
+rights granted or affirmed under this License. For example, you may
+not impose a license fee, royalty, or other charge for exercise of
+rights granted under this License, and you may not initiate litigation
+(including a cross-claim or counterclaim in a lawsuit) alleging that
+any patent claim is infringed by making, using, selling, offering for
+sale, or importing the Program or any portion of it.
+ 11. Patents.
+ A "contributor" is a copyright holder who authorizes use under this
+License of the Program or a work on which the Program is based. The
+work thus licensed is called the contributor's "contributor version".
+ A contributor's "essential patent claims" are all patent claims
+owned or controlled by the contributor, whether already acquired or
+hereafter acquired, that would be infringed by some manner, permitted
+by this License, of making, using, or selling its contributor version,
+but do not include claims that would be infringed only as a
+consequence of further modification of the contributor version. For
+purposes of this definition, "control" includes the right to grant
+patent sublicenses in a manner consistent with the requirements of
+this License.
+ Each contributor grants you a non-exclusive, worldwide, royalty-free
+patent license under the contributor's essential patent claims, to
+make, use, sell, offer for sale, import and otherwise run, modify and
+propagate the contents of its contributor version.
+ In the following three paragraphs, a "patent license" is any express
+agreement or commitment, however denominated, not to enforce a patent
+(such as an express permission to practice a patent or covenant not to
+sue for patent infringement). To "grant" such a patent license to a
+party means to make such an agreement or commitment not to enforce a
+patent against the party.
+ If you convey a covered work, knowingly relying on a patent license,
+and the Corresponding Source of the work is not available for anyone
+to copy, free of charge and under the terms of this License, through a
+publicly available network server or other readily accessible means,
+then you must either (1) cause the Corresponding Source to be so
+available, or (2) arrange to deprive yourself of the benefit of the
+patent license for this particular work, or (3) arrange, in a manner
+consistent with the requirements of this License, to extend the patent
+license to downstream recipients. "Knowingly relying" means you have
+actual knowledge that, but for the patent license, your conveying the
+covered work in a country, or your recipient's use of the covered work
+in a country, would infringe one or more identifiable patents in that
+country that you have reason to believe are valid.
+ If, pursuant to or in connection with a single transaction or
+arrangement, you convey, or propagate by procuring conveyance of, a
+covered work, and grant a patent license to some of the parties
+receiving the covered work authorizing them to use, propagate, modify
+or convey a specific copy of the covered work, then the patent license
+you grant is automatically extended to all recipients of the covered
+work and works based on it.
+ A patent license is "discriminatory" if it does not include within
+the scope of its coverage, prohibits the exercise of, or is
+conditioned on the non-exercise of one or more of the rights that are
+specifically granted under this License. You may not convey a covered
+work if you are a party to an arrangement with a third party that is
+in the business of distributing software, under which you make payment
+to the third party based on the extent of your activity of conveying
+the work, and under which the third party grants, to any of the
+parties who would receive the covered work from you, a discriminatory
+patent license (a) in connection with copies of the covered work
+conveyed by you (or copies made from those copies), or (b) primarily
+for and in connection with specific products or compilations that
+contain the covered work, unless you entered into that arrangement,
+or that patent license was granted, prior to 28 March 2007.
+ Nothing in this License shall be construed as excluding or limiting
+any implied license or other defenses to infringement that may
+otherwise be available to you under applicable patent law.
+ 12. No Surrender of Others' Freedom.
+ If conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License. If you cannot convey a
+covered work so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you may
+not convey it at all. For example, if you agree to terms that obligate you
+to collect a royalty for further conveying from those to whom you convey
+the Program, the only way you could satisfy both those terms and this
+License would be to refrain entirely from conveying the Program.
+ 13. Use with the GNU Affero General Public License.
+ Notwithstanding any other provision of this License, you have
+permission to link or combine any covered work with a work licensed
+under version 3 of the GNU Affero General Public License into a single
+combined work, and to convey the resulting work. The terms of this
+License will continue to apply to the part which is the covered work,
+but the special requirements of the GNU Affero General Public License,
+section 13, concerning interaction through a network will apply to the
+combination as such.
+ 14. Revised Versions of this License.
+ The Free Software Foundation may publish revised and/or new versions of
+the GNU General Public License from time to time. Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+ Each version is given a distinguishing version number. If the
+Program specifies that a certain numbered version of the GNU General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation. If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+ If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+ Later license versions may give you additional or different
+permissions. However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+ 15. Disclaimer of Warranty.
+ 16. Limitation of Liability.
+ 17. Interpretation of Sections 15 and 16.
+ If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+ How to Apply These Terms to Your New Programs
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+ <one line to give the program's name and a brief idea of what it does.>
+ Copyright (C) <year> <name of author>
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ GNU General Public License for more details.
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <>.
+Also add information on how to contact you by electronic and paper mail.
+ If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+ <program> Copyright (C) <year> <name of author>
+ This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+ You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+ The GNU General Public License does not permit incorporating your program
+into proprietary programs. If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License. But first, please read
@@ -1,8 +1,19 @@
rdbl.erl - Erlang readability library
This is Erlang library to extract reasonable content and remove junk from html pages.
-Based on ideas from readability.js by arc90.
+Inspired by readability.js from arc90.
+Source is primary hosted at [github/ivkosh](
+My [Readabilizer service]( is using this library to extract content from web pages.
+Licensing and author
+This library is distributed under the GNU General Public License version 3 and is also available
+under alternative licenses negotiated directly with rdbl author Ivan Koshkin <>.
+The GPL (version 3) is included in this source tree in the file COPYING.
@@ -24,8 +35,9 @@ See other examples in rdbl.erl.
Library uses [mochiweb]( html library to parse HTML-content (included).
-Only following files from mochiweb needed:
+Only following files from mochiweb are needed:
+ mochinum.erl
+ mochiutf8.erl
+ mochiweb_charref.erl
+ mochiweb_html.erl
2 src/
@@ -1,7 +1,7 @@
{application, rdbl,
{description, ""},
- {vsn, "0.3"},
+ {vsn, "0.4"},
{registered, []},
{applications, [
63 src/rdbl.erl
@@ -1,12 +1,28 @@
-%% Erlang readability library inspired by readability.js
%% @author Ivan Koshkin <>
%% @copyright 2011 by Ivan Koshkin
+%% @doc
+%% rdbl.erl - Erlang readability library.
+%% Extracts reasonable content and removes junk from html pages.
+%% @reference See <a href="">Readabilizer</a> service for more information.
+%% @end
+%% This libray is free software: you can redistribute it and/or modify
+%% it under the terms of the GNU General Public License as published by
+%% the Free Software Foundation, either version 3 of the License, or
+%% (at your option) any later version.
+%% This library is distributed in the hope that it will be useful,
+%% but WITHOUT ANY WARRANTY; without even the implied warranty of
+%% GNU General Public License for more details.
+%% You should have received a copy of the GNU General Public License
+%% along with this library. If not, see <>.
-author('Ivan Koshkin <>').
-export([simplify_url/1, simplify_url/2, simplify_file/2, simplify_page/1, simplify_page/3]).
@@ -24,18 +40,14 @@
%% Keeps readability score and additional references for every HTML tree element
-record(score, {
- readability=0,
+ rdbl=0,
-define(RE_NEGATIVE, "\\b(comment|meta|footer|footnote)\\b").
-define(RE_POSITIVE, "\\b(post|hentry|entry[-]?(content|text|body)?|article[-]?(content|text|body)?)\\b").
-define(USER_AGENT, "Safari/5.0.3").
-% TODO: comments are entry-content-only and entry-content, fix this
-% maybe add dependency score algorithm from page url?
-% or maybe commas are not counted???
%% @type scored_html_node() = {string(), score(), [html_attr()], [html_node() | string()]}
@@ -50,6 +62,7 @@
%% @spec simplify_url(string()) -> string()
%% @doc fetches url, simplifies its content and returns simplified page as a string()
%% example: simplify_url("") -> SimplifiedPageText
+%% @end
simplify_url(Url0) ->
Url = add_proto_if_none(Url0),
{ContentType, Body} = fetch_page(Url), % TODO: делать в отдельном процессе и слать сообщение по завершению
@@ -59,6 +72,7 @@ simplify_url(Url0) ->
%% @spec simplify_url(string(), string()) -> ok
%% @doc fetches url, simplifies its content and saves to file
%% example: simplify_url("", "out.html")
+%% @end
simplify_url(Url, FileName) ->
Page = simplify_url(Url),
{ok, F} = file:open(FileName, [binary, write]), % TODO: check if file open
@@ -69,6 +83,7 @@ simplify_url(Url, FileName) ->
%% @spec simplify_file(string(), string()) -> ok
%% @doc reads file from disk, simplifies its content and saves to file
%% example: simplify_url("index.html", "out.html")
+%% @end
simplify_file(FileNameIn, FileNameOut) ->
{ok, Html} = file:read_file(FileNameIn),% TODO: check errors
Page = simplify_page(Html),
@@ -79,6 +94,7 @@ simplify_file(FileNameIn, FileNameOut) ->
%% @spec simplify_page(string()) -> string()
%% @doc wrapper for simplify_page/2 (starts with empty url context)
+%% @end
simplify_page(Body) ->
simplify_page(Body, {"", ""}, "text/html"). % empty context
@@ -107,6 +123,7 @@ extract_content_type(Tree, DefaultContentType) ->
%% @doc main function
%% takes document contens (Body) and document context (Ctx, see url_context/1)
%% returns simplified page as a string()
+%% @end
simplify_page(Body0, Ctx, DefaultContentType) ->
Body = re:replace(Body0, "&nbsp;", " ", [global]), % mochiweb_html:parse has a bug with &nbsp;, just hotfix
try mochiweb_html:parse(Body) of % parse() will not work if Body contains no html tags
@@ -180,18 +197,21 @@ simplify_page(Body0, Ctx, DefaultContentType) ->
%% @spec find_node(reference() | binary(), html_node() | scored_html_node()) -> html_node() | scored_html_node()
%% @doc returns first node from HTML tree with specific HTML tag. If tree is scored, search can be done by node reference
+%% @end
find_node(Ref, HtmlNode) when is_reference(Ref) -> find_node_byref(Ref, HtmlNode);
find_node(Key, HtmlNode) when is_binary(Key) -> find_node_bykey(Key, HtmlNode, first).
%% @spec find_all_nodes(binary(), html_node() | scored_html_node()) -> [html_node() | scored_html_node()]
%% @doc the same as find_node(), but returns all nodes with specific tag as a list
+%% @end
find_all_nodes(Key, HtmlNode) when is_binary(Key) -> find_node_bykey(Key, HtmlNode, multi).
%% @spec find_node_bykey(binary(), html_node() | scored_html_node(), first | multi) -> html_node() | scored_html_node() | [html_node() | scored_html_node()]
%% @doc helper function for find_node() and find_all_nodes()
%% returns:
%% - first element found as html_node() | scored_html_node() if SearchType != multi
%% - list of all found elements as [html_node() | scored_html_node()] if SearchType == multi
+%% @end
find_node_bykey(_, HtmlNode, _) when is_binary(HtmlNode) -> []; % don't searching for leafs
find_node_bykey(_, {comment, _}, _) -> []; % comments in mochiweb_html:parse are 2-element tuples, dropping them
find_node_bykey(Key, Elem, SearchType) when is_tuple(Elem) -> % Element found
@@ -225,6 +245,7 @@ find_node_bykey(Key, [H|T], SearchType) ->
%% @spec find_node_byref(reference(), scored_html_node()) -> scored_html_node()
%% @doc helper function for find_node()
+%% @end
find_node_byref(_Ref, HtmlNode) when is_binary(HtmlNode) -> []; % leaf is not an option
find_node_byref(_, {comment, _}) -> []; % comment is not an option
%tree is already modified, so we have 4-elem tuple in scored_html_node()
@@ -242,6 +263,7 @@ find_node_byref(Ref, [H|T]) -> % walk list if it is not empty
%% @spec remove_node(binary() | [binary()], html_node() | scored_html_node()) -> html_node() | scored_html_node()
%% @doc HTML tag remover. Removes from node all subtrees with Key and returns cleaned html_node() | scored_html_node()
%% example: remove_node(<<"script">>, HtmlTree) -> HtmlTreeWithoutScripts
+%% @end
% if Key is a list - removing all list elements from tree
remove_node([], HtmlTree) -> HtmlTree;
% TODO: неэфективно - дерево пробегается столько раз, какова длина списка ключей.
@@ -266,6 +288,7 @@ remove_node(Key, [H|T]) -> [remove_node(Key, H) | remove_node(Key, T)]. % proces
%% example: replace_node(<<"br">>, <<"p">>, HtmlTree) -> HtmlTreeWithBrReplacedToP
%% example: replace_node(<<"br">>, <<"br">>, fun(L)->TransformedL end, HtmlTree) -> HtmlTreeWithBrReplacedToP
+%% @end
replace_node(Ks, NodeIn) -> replace_node(Ks, fun(L)->L end, NodeIn).
replace_node(_Ks, _Func, NodeIn) when is_binary(NodeIn) -> NodeIn;
@@ -289,6 +312,7 @@ replace_node(Ks, Func, [H|T]) -> [replace_node(Ks, Func, H) | replace_node(Ks, F
%% @spec brbr_to_p(html_node() | scored_html_node()) -> html_node() | scored_html_node()
%% @doc replaces more than 2 <br>s in row with <p>
+%% @end
brbr_to_p(NodeIn) when is_binary(NodeIn) -> NodeIn;
brbr_to_p({comment, _}) -> []; % dropping comments
brbr_to_p({E, A, R}) -> {E, A, brbr_to_p(R)}; % continue to subtree
@@ -302,6 +326,7 @@ brbr_to_p([H|T]) -> [brbr_to_p(H) | brbr_to_p(T)]. % processing list recursively
%% @spec count_commas(html_node() | scored_html_node()) -> int()
%% @doc counts number of commas (,) in HTML tree
+%% @end
count_commas({comment, _}) -> 0;
count_commas({_,_,R}) -> count_commas(R);
count_commas({_,_,_,R}) -> count_commas(R);
@@ -319,6 +344,7 @@ count_commas(Leaf) when is_binary(Leaf) -> lists:foldl(fun(E, S) -> if E == $, -
%% @doc transforms html_node() to scored_html_node(). It now has 4 elements in tuple (not 3 as in mochiweb_html type),
%% the second element in tuple is Score - record of #score, containing readability score, current element ref
%% and ref to parent of current element (see -record(score, ...) below)
+%% @end
init_scores(Tree) -> init_scores(Tree, make_ref()). % adding reference for topmost element too
init_scores(R, _) when is_binary(R) -> R;
@@ -329,20 +355,22 @@ init_scores([H|T], Parent) -> [init_scores(H, Parent) | init_scores(T, Parent)].
%% @spec clean_scores(scored_html_node()) -> html_node()
%% @doc transforms scored tree to normal tree which can be processed by mochiweb_html functions
+%% @end
clean_scores(NodeIn) when is_binary(NodeIn) -> NodeIn;
clean_scores({comment, _}) -> [];
clean_scores({E, _Score, A, Rest}) -> {E, A, clean_scores(Rest)};
-%clean_scores({E, Score, A, Rest}) -> {E, [{<<"readability">>, Score#score.readability}|A], clean_scores(Rest)}; %DEBUG - save score to attrs
+%clean_scores({E, Score, A, Rest}) -> {E, [{<<"rdbl">>, Score#score.rdbl}|A], clean_scores(Rest)}; %DEBUG - save score to attrs
clean_scores({E, A, Rest}) -> {E, A, clean_scores(Rest)};
clean_scores([]) -> [];
clean_scores([H|T]) -> [clean_scores(H) | clean_scores(T)].
%% @spec modify_score(reference(), scored_html_node(), int()) -> scored_html_node()
%% @doc modify readability score for specific element on scored tree. Score is added to current node score
%% e.g. int() is ScoreDiff, to subtract score for element pass negative int()
+%% @end
modify_score(_, Leaf, _) when is_binary(Leaf) -> Leaf;
modify_score(_, {comment, _}, _) -> [];
-modify_score(Ref, {Key, #score{ref=Ref, readability=Rdbl, parent=ParentRef}, A, R}, Score) -> {Key, #score{ref=Ref, readability=Rdbl+Score, parent=ParentRef}, A, R};
+modify_score(Ref, {Key, #score{ref=Ref, rdbl=Rdbl, parent=ParentRef}, A, R}, Score) -> {Key, #score{ref=Ref, rdbl=Rdbl+Score, parent=ParentRef}, A, R};
modify_score(Ref, {E, S, A, R}, Score) -> {E, S, A, modify_score(Ref, R, Score)};
modify_score(_, [], _) -> [];
modify_score(Ref, [H|T], Score) -> [modify_score(Ref, H, Score) | modify_score(Ref, T, Score)].
@@ -356,6 +384,7 @@ modify_score(Ref, [H|T], Score) -> [modify_score(Ref, H, Score) | modify_score(R
%% @spec fetch_page(string()) -> string()
%% @doc fetches url and returns its content as a string()
+%% @end
fetch_page(Url) ->
inets:start(), % TODO: handle errors & not start if already started
@@ -382,6 +411,7 @@ fetch_page(Url) ->
%% @spec clean_html_tree(html_node() | scored_html_node()) -> html_node() | scored_html_node()
%% @doc cleans first-level unreadable junk from html tree
+%% @end
clean_html_tree(Tree) ->
% TODO: add: find max <frame> in frameset and use it as document
@@ -398,6 +428,7 @@ get_title(Tree) ->
%% @spec to_abs_url({binary(), binary()}, string()) -> {binary(), binary()}
%% @doc helper function for simplify_page/2 - converts href & src in element attr to absolute path
+%% @end
to_abs_url({<<"src">>, U}, Ctx) -> {<<"src">>, list_to_binary(full_url(Ctx, binary_to_list(U)))};
to_abs_url({<<"href">>, U}, Ctx) -> {<<"href">>, list_to_binary(full_url(Ctx, binary_to_list(U)))};
to_abs_url(A, _) -> A.
@@ -414,12 +445,13 @@ get_ref(Node) ->
%% @spec get_score(scored_html_node()) -> int()
get_score(Node) ->
- {_, #score{readability=Score}, _, _} = Node,
+ {_, #score{rdbl=Score}, _, _} = Node,
%% @spec score_by_class_or_id(scored_html_node()) -> int()
%% @spec score_by_class_or_id([html_attr()]) -> int()
%% @doc calculates score for node element by its id or class name
+%% @end
score_by_class_or_id({_, _, Attrs, _})-> score_by_class_or_id(Attrs);
score_by_class_or_id([]) -> 0;
score_by_class_or_id(Attrs=[_|_]) ->
@@ -445,6 +477,7 @@ score_by_class_or_id(Attrs=[_|_]) ->
%% @spec score_tree(scored_html_node()) -> scored_html_node()
%% @doc score whole html tree depending on its contents
+%% @end
score_tree(Tree) -> % TODO: do score_tree in parallel (multiplie processes, map+reduce)
Paragraphs = find_all_nodes(<<"p">>, Tree),
%Map1 = [ {1, get_parent_ref(P)} || P <- Paragraphs ], % список вида {1, Parent} для каждого P (пары могут повторяться)
@@ -500,6 +533,7 @@ gather(N, Dict) ->
%% @spec get_max_score_ref(scored_html_node()) -> reference()
%% @doc finds ref to node with maximum readability score
+%% @end
get_max_score_ref(Tree) ->
{Ref, _MaxScore} = lists:foldl(
fun({Ref, Score}, {Ref0, Score0}) ->
@@ -517,16 +551,18 @@ get_max_score_ref(Tree) ->
%% @spec score_list(scored_html_node()) -> [{reference(), int()}]
%% @doc builds list of pairs {Node_Ref, Node_Score} from html tree
%% helper function for get_max_score_ref()
+%% @end
score_list(HtmlNode) when is_binary(HtmlNode) -> []; % leaf
score_list({comment, _}) -> [];
-score_list({_, #score{readability=Rdbl, ref=Ref}, _, R}) -> [{Ref, Rdbl} | score_list(R)];
+score_list({_, #score{rdbl=Rdbl, ref=Ref}, _, R}) -> [{Ref, Rdbl} | score_list(R)];
score_list({_, _, _, R}) -> score_list(R);
score_list([]) -> [];
score_list([H|T]) -> score_list(H) ++ score_list(T).
%% @spec url_context(string()) -> {string(), string()}
%% @doc returns the domain, and current context path.
%% example: url_context(" -> {"", "/content"}
+%% @end
url_context(URL) ->
case http_uri:parse(URL) of
{Proto, _, Root, _Port, Path, _Query} ->
@@ -538,6 +574,7 @@ url_context(URL) ->
%% @spec full_url({string(), string()}, string()) -> string()
%% @doc example: full_url(url_context(""), "img/pic.gif" -> ""
+%% @end
full_url({Root, _Context}, ComponentUrl=[$/|_]) -> Root ++ ComponentUrl; % abs url inside the same server: /img/pig.gif
full_url({_Root, _Context}, ComponentUrl="http://"++_) -> ComponentUrl; % full url
full_url({_Root, _Context}, ComponentUrl="https://"++_) -> ComponentUrl;

0 comments on commit 0ead1f2

Please sign in to comment.