| Name | comber JSON |
| Version |
1.0.0
JSON |
| download |
| home_page | None |
| Summary | Parser combinator library with a BNF-esque interface |
| upload_time | 2025-02-16 19:38:06 |
| maintainer | None |
| docs_url | None |
| author | None |
| requires_python | >=3.10 |
| license | GNU LESSER GENERAL PUBLIC LICENSE
Version 2.1, February 1999
Copyright (C) 1991, 1999 Free Software Foundation, Inc.
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
[This is the first released version of the Lesser GPL. It also counts
as the successor of the GNU Library Public License, version 2, hence
the version number 2.1.]
Preamble
The licenses for most software are designed to take away your
freedom to share and change it. By contrast, the GNU General Public
Licenses are intended to guarantee your freedom to share and change
free software--to make sure the software is free for all its users.
This license, the Lesser General Public License, applies to some
specially designated software packages--typically libraries--of the
Free Software Foundation and other authors who decide to use it. You
can use it too, but we suggest you first think carefully about whether
this license or the ordinary General Public License is the better
strategy to use in any particular case, based on the explanations below.
When we speak of free software, we are referring to freedom of use,
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 this service if you wish); that you receive source code or can get
it if you want it; that you can change the software and use pieces of
it in new free programs; and that you are informed that you can do
these things.
To protect your rights, we need to make restrictions that forbid
distributors to deny you these rights or to ask you to surrender these
rights. These restrictions translate to certain responsibilities for
you if you distribute copies of the library or if you modify it.
For example, if you distribute copies of the library, whether gratis
or for a fee, you must give the recipients all the rights that we gave
you. You must make sure that they, too, receive or can get the source
code. If you link other code with the library, you must provide
complete object files to the recipients, so that they can relink them
with the library after making changes to the library and recompiling
it. And you must show them these terms so they know their rights.
We protect your rights with a two-step method: (1) we copyright the
library, and (2) we offer you this license, which gives you legal
permission to copy, distribute and/or modify the library.
To protect each distributor, we want to make it very clear that
there is no warranty for the free library. Also, if the library is
modified by someone else and passed on, the recipients should know
that what they have is not the original version, so that the original
author's reputation will not be affected by problems that might be
introduced by others.
Finally, software patents pose a constant threat to the existence of
any free program. We wish to make sure that a company cannot
effectively restrict the users of a free program by obtaining a
restrictive license from a patent holder. Therefore, we insist that
any patent license obtained for a version of the library must be
consistent with the full freedom of use specified in this license.
Most GNU software, including some libraries, is covered by the
ordinary GNU General Public License. This license, the GNU Lesser
General Public License, applies to certain designated libraries, and
is quite different from the ordinary General Public License. We use
this license for certain libraries in order to permit linking those
libraries into non-free programs.
When a program is linked with a library, whether statically or using
a shared library, the combination of the two is legally speaking a
combined work, a derivative of the original library. The ordinary
General Public License therefore permits such linking only if the
entire combination fits its criteria of freedom. The Lesser General
Public License permits more lax criteria for linking other code with
the library.
We call this license the "Lesser" General Public License because it
does Less to protect the user's freedom than the ordinary General
Public License. It also provides other free software developers Less
of an advantage over competing non-free programs. These disadvantages
are the reason we use the ordinary General Public License for many
libraries. However, the Lesser license provides advantages in certain
special circumstances.
For example, on rare occasions, there may be a special need to
encourage the widest possible use of a certain library, so that it becomes
a de-facto standard. To achieve this, non-free programs must be
allowed to use the library. A more frequent case is that a free
library does the same job as widely used non-free libraries. In this
case, there is little to gain by limiting the free library to free
software only, so we use the Lesser General Public License.
In other cases, permission to use a particular library in non-free
programs enables a greater number of people to use a large body of
free software. For example, permission to use the GNU C Library in
non-free programs enables many more people to use the whole GNU
operating system, as well as its variant, the GNU/Linux operating
system.
Although the Lesser General Public License is Less protective of the
users' freedom, it does ensure that the user of a program that is
linked with the Library has the freedom and the wherewithal to run
that program using a modified version of the Library.
The precise terms and conditions for copying, distribution and
modification follow. Pay close attention to the difference between a
"work based on the library" and a "work that uses the library". The
former contains code derived from the library, whereas the latter must
be combined with the library in order to run.
GNU LESSER GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License Agreement applies to any software library or other
program which contains a notice placed by the copyright holder or
other authorized party saying it may be distributed under the terms of
this Lesser General Public License (also called "this License").
Each licensee is addressed as "you".
A "library" means a collection of software functions and/or data
prepared so as to be conveniently linked with application programs
(which use some of those functions and data) to form executables.
The "Library", below, refers to any such software library or work
which has been distributed under these terms. A "work based on the
Library" means either the Library or any derivative work under
copyright law: that is to say, a work containing the Library or a
portion of it, either verbatim or with modifications and/or translated
straightforwardly into another language. (Hereinafter, translation is
included without limitation in the term "modification".)
"Source code" for a work means the preferred form of the work for
making modifications to it. For a library, complete source code means
all the source code for all modules it contains, plus any associated
interface definition files, plus the scripts used to control compilation
and installation of the library.
Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope. The act of
running a program using the Library is not restricted, and output from
such a program is covered only if its contents constitute a work based
on the Library (independent of the use of the Library in a tool for
writing it). Whether that is true depends on what the Library does
and what the program that uses the Library does.
1. You may copy and distribute verbatim copies of the Library's
complete source code as you receive it, in any medium, provided that
you conspicuously and appropriately publish on each copy an
appropriate copyright notice and disclaimer of warranty; keep intact
all the notices that refer to this License and to the absence of any
warranty; and distribute a copy of this License along with the
Library.
You may charge a fee for the physical act of transferring a copy,
and you may at your option offer warranty protection in exchange for a
fee.
2. You may modify your copy or copies of the Library or any portion
of it, thus forming a work based on the Library, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
a) The modified work must itself be a software library.
b) You must cause the files modified to carry prominent notices
stating that you changed the files and the date of any change.
c) You must cause the whole of the work to be licensed at no
charge to all third parties under the terms of this License.
d) If a facility in the modified Library refers to a function or a
table of data to be supplied by an application program that uses
the facility, other than as an argument passed when the facility
is invoked, then you must make a good faith effort to ensure that,
in the event an application does not supply such function or
table, the facility still operates, and performs whatever part of
its purpose remains meaningful.
(For example, a function in a library to compute square roots has
a purpose that is entirely well-defined independent of the
application. Therefore, Subsection 2d requires that any
application-supplied function or table used by this function must
be optional: if the application does not supply it, the square
root function must still compute square roots.)
These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the Library,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works. But when you
distribute the same sections as part of a whole which is a work based
on the Library, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote
it.
Thus, it is not the intent of this section to claim rights or contest
your rights to work written entirely by you; rather, the intent is to
exercise the right to control the distribution of derivative or
collective works based on the Library.
In addition, mere aggregation of another work not based on the Library
with the Library (or with a work based on the Library) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.
3. You may opt to apply the terms of the ordinary GNU General Public
License instead of this License to a given copy of the Library. To do
this, you must alter all the notices that refer to this License, so
that they refer to the ordinary GNU General Public License, version 2,
instead of to this License. (If a newer version than version 2 of the
ordinary GNU General Public License has appeared, then you can specify
that version instead if you wish.) Do not make any other change in
these notices.
Once this change is made in a given copy, it is irreversible for
that copy, so the ordinary GNU General Public License applies to all
subsequent copies and derivative works made from that copy.
This option is useful when you wish to copy part of the code of
the Library into a program that is not a library.
4. You may copy and distribute the Library (or a portion or
derivative of it, under Section 2) in object code or executable form
under the terms of Sections 1 and 2 above provided that you accompany
it with the complete corresponding machine-readable source code, which
must be distributed under the terms of Sections 1 and 2 above on a
medium customarily used for software interchange.
If distribution of object code is made by offering access to copy
from a designated place, then offering equivalent access to copy the
source code from the same place satisfies the requirement to
distribute the source code, even though third parties are not
compelled to copy the source along with the object code.
5. A program that contains no derivative of any portion of the
Library, but is designed to work with the Library by being compiled or
linked with it, is called a "work that uses the Library". Such a
work, in isolation, is not a derivative work of the Library, and
therefore falls outside the scope of this License.
However, linking a "work that uses the Library" with the Library
creates an executable that is a derivative of the Library (because it
contains portions of the Library), rather than a "work that uses the
library". The executable is therefore covered by this License.
Section 6 states terms for distribution of such executables.
When a "work that uses the Library" uses material from a header file
that is part of the Library, the object code for the work may be a
derivative work of the Library even though the source code is not.
Whether this is true is especially significant if the work can be
linked without the Library, or if the work is itself a library. The
threshold for this to be true is not precisely defined by law.
If such an object file uses only numerical parameters, data
structure layouts and accessors, and small macros and small inline
functions (ten lines or less in length), then the use of the object
file is unrestricted, regardless of whether it is legally a derivative
work. (Executables containing this object code plus portions of the
Library will still fall under Section 6.)
Otherwise, if the work is a derivative of the Library, you may
distribute the object code for the work under the terms of Section 6.
Any executables containing that work also fall under Section 6,
whether or not they are linked directly with the Library itself.
6. As an exception to the Sections above, you may also combine or
link a "work that uses the Library" with the Library to produce a
work containing portions of the Library, and distribute that work
under terms of your choice, provided that the terms permit
modification of the work for the customer's own use and reverse
engineering for debugging such modifications.
You must give prominent notice with each copy of the work that the
Library is used in it and that the Library and its use are covered by
this License. You must supply a copy of this License. If the work
during execution displays copyright notices, you must include the
copyright notice for the Library among them, as well as a reference
directing the user to the copy of this License. Also, you must do one
of these things:
a) Accompany the work with the complete corresponding
machine-readable source code for the Library including whatever
changes were used in the work (which must be distributed under
Sections 1 and 2 above); and, if the work is an executable linked
with the Library, with the complete machine-readable "work that
uses the Library", as object code and/or source code, so that the
user can modify the Library and then relink to produce a modified
executable containing the modified Library. (It is understood
that the user who changes the contents of definitions files in the
Library will not necessarily be able to recompile the application
to use the modified definitions.)
b) Use a suitable shared library mechanism for linking with the
Library. A suitable mechanism is one that (1) uses at run time a
copy of the library already present on the user's computer system,
rather than copying library functions into the executable, and (2)
will operate properly with a modified version of the library, if
the user installs one, as long as the modified version is
interface-compatible with the version that the work was made with.
c) Accompany the work with a written offer, valid for at
least three years, to give the same user the materials
specified in Subsection 6a, above, for a charge no more
than the cost of performing this distribution.
d) If distribution of the work is made by offering access to copy
from a designated place, offer equivalent access to copy the above
specified materials from the same place.
e) Verify that the user has already received a copy of these
materials or that you have already sent this user a copy.
For an executable, the required form of the "work that uses the
Library" must include any data and utility programs needed for
reproducing the executable from it. However, as a special exception,
the materials to be distributed need not include anything that is
normally distributed (in either source or binary form) with the major
components (compiler, kernel, and so on) of the operating system on
which the executable runs, unless that component itself accompanies
the executable.
It may happen that this requirement contradicts the license
restrictions of other proprietary libraries that do not normally
accompany the operating system. Such a contradiction means you cannot
use both them and the Library together in an executable that you
distribute.
7. You may place library facilities that are a work based on the
Library side-by-side in a single library together with other library
facilities not covered by this License, and distribute such a combined
library, provided that the separate distribution of the work based on
the Library and of the other library facilities is otherwise
permitted, and provided that you do these two things:
a) Accompany the combined library with a copy of the same work
based on the Library, uncombined with any other library
facilities. This must be distributed under the terms of the
Sections above.
b) Give prominent notice with the combined library of the fact
that part of it is a work based on the Library, and explaining
where to find the accompanying uncombined form of the same work.
8. You may not copy, modify, sublicense, link with, or distribute
the Library except as expressly provided under this License. Any
attempt otherwise to copy, modify, sublicense, link with, or
distribute the Library is void, and will automatically terminate your
rights under this License. However, parties who have received copies,
or rights, from you under this License will not have their licenses
terminated so long as such parties remain in full compliance.
9. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify or
distribute the Library or its derivative works. These actions are
prohibited by law if you do not accept this License. Therefore, by
modifying or distributing the Library (or any work based on the
Library), you indicate your acceptance of this License to do so, and
all its terms and conditions for copying, distributing or modifying
the Library or works based on it.
10. Each time you redistribute the Library (or any work based on the
Library), the recipient automatically receives a license from the
original licensor to copy, distribute, link with or modify the Library
subject to these terms and conditions. You may not impose any further
restrictions on the recipients' exercise of the rights granted herein.
You are not responsible for enforcing compliance by third parties with
this License.
11. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent issues),
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
distribute so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you
may not distribute the Library at all. For example, if a patent
license would not permit royalty-free redistribution of the Library by
all those who receive copies directly or indirectly through you, then
the only way you could satisfy both it and this License would be to
refrain entirely from distribution of the Library.
If any portion of this section is held invalid or unenforceable under any
particular circumstance, the balance of the section is intended to apply,
and the section as a whole is intended to apply in other circumstances.
It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of any
such claims; this section has the sole purpose of protecting the
integrity of the free software distribution system which is
implemented by public license practices. Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
system; it is up to the author/donor to decide if he or she is willing
to distribute software through any other system and a licensee cannot
impose that choice.
This section is intended to make thoroughly clear what is believed to
be a consequence of the rest of this License.
12. If the distribution and/or use of the Library is restricted in
certain countries either by patents or by copyrighted interfaces, the
original copyright holder who places the Library under this License may add
an explicit geographical distribution limitation excluding those countries,
so that distribution is permitted only in or among countries not thus
excluded. In such case, this License incorporates the limitation as if
written in the body of this License.
13. The Free Software Foundation may publish revised and/or new
versions of the Lesser 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 Library
specifies a version number of this License which applies to it and
"any later version", you have the option of following the terms and
conditions either of that version or of any later version published by
the Free Software Foundation. If the Library does not specify a
license version number, you may choose any version ever published by
the Free Software Foundation.
14. If you wish to incorporate parts of the Library into other free
programs whose distribution conditions are incompatible with these,
write to the author to ask for permission. For software which is
copyrighted by the Free Software Foundation, write to the Free
Software Foundation; we sometimes make exceptions for this. Our
decision will be guided by the two goals of preserving the free status
of all derivatives of our free software and of promoting the sharing
and reuse of software generally.
NO WARRANTY
15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO
WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR
OTHER PARTIES PROVIDE THE LIBRARY "AS IS" WITHOUT WARRANTY OF ANY
KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE
LIBRARY IS WITH YOU. SHOULD THE LIBRARY PROVE DEFECTIVE, YOU ASSUME
THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
16. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY
AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE LIABLE TO YOU
FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
LIBRARY (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
FAILURE OF THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Libraries
If you develop a new library, and you want it to be of the greatest
possible use to the public, we recommend making it free software that
everyone can redistribute and change. You can do so by permitting
redistribution under these terms (or, alternatively, under the terms of the
ordinary General Public License).
To apply these terms, attach the following notices to the library. It is
safest to attach them to the start of each source file to most effectively
convey 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 library's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
USA
Also add information on how to contact you by electronic and paper mail.
You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the library, if
necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the
library `Frob' (a library for tweaking knobs) written by James Random
Hacker.
<signature of Ty Coon>, 1 April 1990
Ty Coon, President of Vice
That's all there is to it!
|
| keywords |
parser
combinator
parsing
compiler
|
| VCS |
 |
| bugtrack_url |
|
| requirements |
No requirements were recorded.
|
| Travis-CI |
No Travis.
|
| coveralls test coverage |
No coveralls.
|
""""""
Comber
""""""
Comber is a parser combinator library for creating text parsers in plain Python with a BNF flavor.
For instance, we could define a simple grammar for calling functions on integer values like this:
.. code-block:: python
from comber import C, rs, inf
keyword = rs(r'[_a-zA-Z][_a-zA-Z0-9]*')@('keyword')
number = rs(r'[0-9]+')@('number', int)
package = keyword[1, inf, ',']
import_statement = C+ 'import' + package
value = keyword | number
function_call = keyword + '(' + value**',' + ')'
assignment = C+ 'let' + keyword + '=' + (function_call | value)
grammar = (import_statement | assignment | function_call)[0, inf]
Our toy grammar can handle simple import statements, variable assignment, and function calling. For example::
import math
import sys.io
let user_number = read()
let double = multiple(user_number, 2)
print(double)
To use our parser, we simply pass a string to it:
.. code-block:: python
from comber import ParseError
code = "add(17, 3)"
try:
parseState = grammar(code)
print('Parsed tokens: %s' % parseState.tree)
except ParseError as ex:
print(ex)
The ``grammar`` call returns the final parser state on a successful parse, from which you can retrieve the final parse
tree. In our case, it is effectively a list::
['add', '(', 17, 3, ')']
Our grammar only supports variables and integers. Suppose we tried to assign pythong-style string to a variable::
let text = "Here's some text"
If we tried to parse this, we'd get an exception like::
1:12: Unexpected Text: "Here's som. Expected one of: @keyword, @number
----------
.. contents:: Contents
:depth: 3
================
Building Parsers
================
The most basic parsers are string literals (which match exactly), ``rs`` for matching a regular expression, and ``cs`` for
matching any of the strings of an iterable.
The ``rs`` parser can be seen in our toy grammar above. Standard Python regular expressions are supported. The entire
match is used as the result of the parse, regardless of groupings etc.
The ``cs`` parse takes any iterable of strings. The first string that exactly matches (the start of) the input text. If
none of the strings match, the parse fails. Since strings are themselves iterables, we could add addition and
subtraction to our toy grammar like this:
.. code-block:: python
from comber import C, cs
addition = value + cs('+-') + value
assignment = C+ 'let' + keyword + '=' + (addition | function_call | value)
String literals can only be used in combination with other parsers. If a string literal would start a sequence, or
otherwise appear alone, make use of the C parser.
------------
The C Parser
------------
The C parser, on its own, consumes no text, produces no tokens, and always succeeds. It's most useful for starting a
parser that would otherwise begin with a string literal. E.g. this:
.. code-block:: python
'let' + keyword + '=' + (function_call | value)
would actually throw a Python error because 'let' isn't *really* a parser - yet! That's where ``C`` comes in:
.. code-block:: python
C+ 'let' + keyword + '=' + (function_call | value)
``C`` starts off the sequence, so we can use any combination of parsers and string literals we like from there. It works
similarly with alternatives, so if we wanted to allow ``set`` to be used as a synonym for ``let``, we might do:
.. code-block:: python
(C| 'let'|'set') + keyword + '=' + (function_call | value)
``C`` can also be used to wrap a parser to protect it from optimization; for instance, embedding one sequence or
alternative set inside another. If, for instance, we extended our grammar to allow a bare value to be a whole statement:
.. code-block:: python
value = (keyword | number)@'value'
grammar = (import_statement | assignment | function_call | value)[0, inf]
-----------------
Basic Combinators
-----------------
Parsers can be combined in series with ``+``:
.. code-block:: python
name + address + pet
A sequence of parsers is evaluated left to right, each consuming text before the next is evaluated. If at any point in
the sequence a parser fails, the entire sequence fails.
A set of alternatives is built with ``|``:
.. code-block:: python
name | idnumber | location
Alternatives are considered left to right, with the first successful match being the match for the entire set. Be
careful! This means that for some sets of alternatives, the "obvious" parser may not be the one used, simply because it
came after another match.
Both sequences and alternatives will flatten like combinators, such that:
.. code-block:: python
name = firstname + lastname
salutation = C+ 'Hello' + name + '!'
is equivalent to:
.. code-block:: python
salutation = C+ 'Hello' + firstname + lastname + '!'
If you need to mantain the logical separation (to parse correctly, or maintain the name of a subparser), wrap the
subparser with ``C``:
.. code-block:: python
name = C(firstname + lastname)
salutation = C+ 'Hello' + name + '!'
----------
Repetition
----------
The most flexible option for specifying repetition is brackets:
.. code-block:: python
keyword[0, 10, ',']
The above would parse ``keyword`` zero to ten times, separated by a comma. The separator is optional - without it, the
result would simply parse ``keyword`` zero to ten times.
We could also specify parsing an exact number of times:
.. code-block:: python
keyword[10]
Or, with a separator:
.. code-block:: python
keyword[10, None, ',']
Infinity - ``math.inf`` - is a valid maximum value. For convenience, it can be imported directly from Comber:
.. code-block:: python
from comber import inf
param_list = keyword[0, inf, ',']
There are several convenience combinators for common types of repetition.
For zero or more with a separator, using ``*``:
.. code-block:: python
parser*','
Or zero or more without a separator, using the unary ``+``:
.. code-block:: python
+parser
You can declare a parser as *optional* with ``~``:
.. code-block:: python
~parser
------------------
Recursive Grammars
------------------
Consider a program in our toy grammar::
let word = exp(2, 16)
let maxint = minus(word, 1)
It'd be nice to simplify this by eliminating the variable "word" and pass the exp() call directly to minus(), but to
allow that, we need to extend our grammar to consider a function call to be a value so we can use one as a function
argument. But to do that, we'd need to use ``function_call`` in our definition of ``value`` - but ``function_call`` likewise
needs to reference ``value``.
To solve this issue, we can define one of them as ``defer``.
.. code-block:: python
from comber import C, rs, inf, defer
...
value = defer()
function_call = keyword + '(' + value**',' + ')'
value.fill(keyword | number | function_call)
This way, we can refer to ``value`` wherever we want, and only define its meaning when we're ready. We can safely build
fairly complex grammars this way, but be wary of performance.
-----------------
Controlling Space
-----------------
Before each subparser is run, Comber consumes leading whitespace. By default, this is spaces, tabs, and newlines. You
can change this in two ways: set the ``whitespace`` property on the outermost parser to a string containing the new
whitespace characters, or likewise passing a string as the second argument to the parser. In either case, the value
``None`` will disable the feature altogether.
====================
Building Parse Trees
====================
When you call a parser on a some text, they return a ``State`` object containing the resultant parse tree (``State.tree``).
By default, parsers output a "flat" tree - a list of strings parsed by the "leaf" parsers (i.e. string literals,
``rs``, and ``cs``).
To build a more useful parse tree, you have to provide *emitters*. Our toy grammar contains a simple one that converts
integers in the input to Python ``int`` values:
.. code-block:: Python
number = rs(r'[0-9]+')@('number', int)
So if we ran our parser on the input "let foo = 5" the resulting state's ``tree`` property would be ``["let", "foo", "=",
5]``. But it'd be more useful if it resulted in some kind of "let" object (that could execute the assignment, or be fed
to a VM, or whatever else). We could define one we can use as a emitter for our let statement like this:
.. code-block:: Python
class Let:
def __init__(self, let, variable, eq, value):
self.variable = variable
self.value = value
# We can ignore `let` and `eq` (which will always contain "let" and "=", respectively).
def __repr__(self):
return f'Let({self.variable}, {self.value})'
and redefine the assignment rule like:
.. code-block:: Python
assignment = (C+ 'let' + keyword + '=' + (function_call | value))@Let
Now if rerun the parser on "let foo = 5", we get ``[Let(foo, 5)]``.
As we did with number, you can also combine an emitter with a name, to improve error messages:
.. code-block:: Python
assignment = (C+ 'let' + keyword + '=' + (function_call | value))@("assignment", Let)
===========
Performance
===========
Under the covers, Comber is essentially a recursive descent parser. It's best suited for relatively shallow grammars
parsing small amounts of text.
You can gain a bit more speed by calling ``analyze()`` on the top-level/outermost parser. This modifies the parser (and
subparsers) in place:
.. code-block:: Python
grammar.analyze()
grammar('max(1, 4)'
====
TODO
====
-------------------
Available Operators
-------------------
Operators that Python allows to overridden
======== ============== ===========
Operator Method Current use
======== ============== ===========
\+ __add__ sequences
\| __or__ selection
[ ] __getitem__ repeat
@ __matmul__ names and internalization
< __lt__
> __gt__
<= __le__
>= __ge__
== __eq__
!= __ne__
is _is
is not is_not
\- __sub__
% __mod__
\* __mul__ zero or more, with provided separator
\** __pow__
/ __truediv__
// __floordiv__
& __and__
^ __xor__
<< __lshift__
>> __rshift__
in __contains__
======== ============== ===========
Unary operators:
======== =========== ===========
Operator Method Current use
======== =========== ===========
~ __invert__ optional
not __not__
\- __neg__
\+ __pos__ zero or more
======== =========== ===========
And::
() __call__ parse a string
=========
Copyright
=========
Comber copyright 2025 Ray Wallace III
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, **version 2.1**.
This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
Raw data
{
"_id": null,
"home_page": null,
"name": "comber",
"maintainer": null,
"docs_url": null,
"requires_python": ">=3.10",
"maintainer_email": null,
"keywords": "parser, combinator, parsing, compiler",
"author": null,
"author_email": "Ray Wallace III <rwallace3@proton.me>",
"download_url": "https://files.pythonhosted.org/packages/f2/56/7eb99f97948d4ae2a0d990916200c791b691135ab3f0a1ac2bf719ce4f89/comber-1.0.0.tar.gz",
"platform": null,
"description": "\"\"\"\"\"\"\nComber\n\"\"\"\"\"\"\n\nComber is a parser combinator library for creating text parsers in plain Python with a BNF flavor.\n\nFor instance, we could define a simple grammar for calling functions on integer values like this:\n\n.. code-block:: python\n\n from comber import C, rs, inf\n \n keyword = rs(r'[_a-zA-Z][_a-zA-Z0-9]*')@('keyword')\n number = rs(r'[0-9]+')@('number', int)\n package = keyword[1, inf, ',']\n import_statement = C+ 'import' + package\n value = keyword | number\n function_call = keyword + '(' + value**',' + ')'\n assignment = C+ 'let' + keyword + '=' + (function_call | value)\n grammar = (import_statement | assignment | function_call)[0, inf]\n\nOur toy grammar can handle simple import statements, variable assignment, and function calling. For example::\n\n import math\n import sys.io\n \n let user_number = read()\n let double = multiple(user_number, 2)\n \n print(double)\n\nTo use our parser, we simply pass a string to it:\n\n.. code-block:: python\n\n from comber import ParseError\n\n code = \"add(17, 3)\"\n try:\n parseState = grammar(code)\n print('Parsed tokens: %s' % parseState.tree)\n except ParseError as ex:\n print(ex)\n\nThe ``grammar`` call returns the final parser state on a successful parse, from which you can retrieve the final parse\ntree. In our case, it is effectively a list::\n\n ['add', '(', 17, 3, ')']\n\nOur grammar only supports variables and integers. Suppose we tried to assign pythong-style string to a variable::\n \n let text = \"Here's some text\"\n\nIf we tried to parse this, we'd get an exception like::\n\n 1:12: Unexpected Text: \"Here's som. Expected one of: @keyword, @number\n\n\n----------\n\n.. contents:: Contents\n :depth: 3\n\n\n================\nBuilding Parsers\n================\n\nThe most basic parsers are string literals (which match exactly), ``rs`` for matching a regular expression, and ``cs`` for\nmatching any of the strings of an iterable.\n\nThe ``rs`` parser can be seen in our toy grammar above. Standard Python regular expressions are supported. The entire\nmatch is used as the result of the parse, regardless of groupings etc.\n\nThe ``cs`` parse takes any iterable of strings. The first string that exactly matches (the start of) the input text. If\nnone of the strings match, the parse fails. Since strings are themselves iterables, we could add addition and\nsubtraction to our toy grammar like this:\n\n.. code-block:: python\n\n from comber import C, cs\n\n addition = value + cs('+-') + value\n assignment = C+ 'let' + keyword + '=' + (addition | function_call | value)\n\nString literals can only be used in combination with other parsers. If a string literal would start a sequence, or\notherwise appear alone, make use of the C parser.\n\n------------\nThe C Parser\n------------\n\nThe C parser, on its own, consumes no text, produces no tokens, and always succeeds. It's most useful for starting a\nparser that would otherwise begin with a string literal. E.g. this:\n\n.. code-block:: python\n\n 'let' + keyword + '=' + (function_call | value)\n\nwould actually throw a Python error because 'let' isn't *really* a parser - yet! That's where ``C`` comes in:\n\n.. code-block:: python\n\n C+ 'let' + keyword + '=' + (function_call | value)\n\n``C`` starts off the sequence, so we can use any combination of parsers and string literals we like from there. It works\nsimilarly with alternatives, so if we wanted to allow ``set`` to be used as a synonym for ``let``, we might do:\n\n.. code-block:: python\n\n (C| 'let'|'set') + keyword + '=' + (function_call | value)\n\n``C`` can also be used to wrap a parser to protect it from optimization; for instance, embedding one sequence or\nalternative set inside another. If, for instance, we extended our grammar to allow a bare value to be a whole statement:\n\n.. code-block:: python\n\n value = (keyword | number)@'value'\n grammar = (import_statement | assignment | function_call | value)[0, inf]\n\n\n-----------------\nBasic Combinators\n-----------------\n\nParsers can be combined in series with ``+``:\n\n.. code-block:: python\n\n name + address + pet\n\nA sequence of parsers is evaluated left to right, each consuming text before the next is evaluated. If at any point in\nthe sequence a parser fails, the entire sequence fails.\n\nA set of alternatives is built with ``|``:\n\n.. code-block:: python\n\n name | idnumber | location\n\nAlternatives are considered left to right, with the first successful match being the match for the entire set. Be\ncareful! This means that for some sets of alternatives, the \"obvious\" parser may not be the one used, simply because it\ncame after another match. \n\nBoth sequences and alternatives will flatten like combinators, such that:\n\n.. code-block:: python\n\n name = firstname + lastname\n salutation = C+ 'Hello' + name + '!'\n\nis equivalent to:\n\n.. code-block:: python\n\n salutation = C+ 'Hello' + firstname + lastname + '!'\n\nIf you need to mantain the logical separation (to parse correctly, or maintain the name of a subparser), wrap the\nsubparser with ``C``:\n\n.. code-block:: python\n\n name = C(firstname + lastname)\n salutation = C+ 'Hello' + name + '!'\n\n----------\nRepetition\n----------\n\nThe most flexible option for specifying repetition is brackets:\n\n.. code-block:: python\n\n keyword[0, 10, ',']\n\nThe above would parse ``keyword`` zero to ten times, separated by a comma. The separator is optional - without it, the\nresult would simply parse ``keyword`` zero to ten times.\n\nWe could also specify parsing an exact number of times:\n\n.. code-block:: python\n\n keyword[10]\n\nOr, with a separator: \n\n.. code-block:: python\n\n keyword[10, None, ',']\n\nInfinity - ``math.inf`` - is a valid maximum value. For convenience, it can be imported directly from Comber:\n\n.. code-block:: python\n\n from comber import inf\n\n param_list = keyword[0, inf, ',']\n\nThere are several convenience combinators for common types of repetition.\n\nFor zero or more with a separator, using ``*``:\n\n.. code-block:: python\n\n parser*','\n\nOr zero or more without a separator, using the unary ``+``:\n\n.. code-block:: python\n\n +parser\n\nYou can declare a parser as *optional* with ``~``:\n\n.. code-block:: python\n\n ~parser\n\n------------------\nRecursive Grammars\n------------------\n\nConsider a program in our toy grammar::\n\n let word = exp(2, 16)\n let maxint = minus(word, 1)\n\nIt'd be nice to simplify this by eliminating the variable \"word\" and pass the exp() call directly to minus(), but to\nallow that, we need to extend our grammar to consider a function call to be a value so we can use one as a function\nargument. But to do that, we'd need to use ``function_call`` in our definition of ``value`` - but ``function_call`` likewise\nneeds to reference ``value``.\n\nTo solve this issue, we can define one of them as ``defer``.\n\n.. code-block:: python\n\n from comber import C, rs, inf, defer\n\n ...\n\n value = defer()\n function_call = keyword + '(' + value**',' + ')'\n value.fill(keyword | number | function_call)\n\nThis way, we can refer to ``value`` wherever we want, and only define its meaning when we're ready. We can safely build\nfairly complex grammars this way, but be wary of performance.\n\n-----------------\nControlling Space\n-----------------\n\nBefore each subparser is run, Comber consumes leading whitespace. By default, this is spaces, tabs, and newlines. You\ncan change this in two ways: set the ``whitespace`` property on the outermost parser to a string containing the new\nwhitespace characters, or likewise passing a string as the second argument to the parser. In either case, the value\n``None`` will disable the feature altogether.\n\n====================\nBuilding Parse Trees\n====================\n\nWhen you call a parser on a some text, they return a ``State`` object containing the resultant parse tree (``State.tree``).\n\nBy default, parsers output a \"flat\" tree - a list of strings parsed by the \"leaf\" parsers (i.e. string literals,\n``rs``, and ``cs``).\n\nTo build a more useful parse tree, you have to provide *emitters*. Our toy grammar contains a simple one that converts\nintegers in the input to Python ``int`` values:\n\n.. code-block:: Python\n\n number = rs(r'[0-9]+')@('number', int)\n\nSo if we ran our parser on the input \"let foo = 5\" the resulting state's ``tree`` property would be ``[\"let\", \"foo\", \"=\",\n5]``. But it'd be more useful if it resulted in some kind of \"let\" object (that could execute the assignment, or be fed\nto a VM, or whatever else). We could define one we can use as a emitter for our let statement like this:\n\n.. code-block:: Python\n\n class Let:\n def __init__(self, let, variable, eq, value):\n self.variable = variable\n self.value = value\n # We can ignore `let` and `eq` (which will always contain \"let\" and \"=\", respectively).\n\n def __repr__(self):\n return f'Let({self.variable}, {self.value})'\n\nand redefine the assignment rule like:\n\n.. code-block:: Python\n\n assignment = (C+ 'let' + keyword + '=' + (function_call | value))@Let\n\nNow if rerun the parser on \"let foo = 5\", we get ``[Let(foo, 5)]``.\n\nAs we did with number, you can also combine an emitter with a name, to improve error messages:\n\n.. code-block:: Python\n\n assignment = (C+ 'let' + keyword + '=' + (function_call | value))@(\"assignment\", Let)\n\n===========\nPerformance\n===========\n\nUnder the covers, Comber is essentially a recursive descent parser. It's best suited for relatively shallow grammars\nparsing small amounts of text.\n\nYou can gain a bit more speed by calling ``analyze()`` on the top-level/outermost parser. This modifies the parser (and\nsubparsers) in place:\n\n.. code-block:: Python\n\n grammar.analyze()\n grammar('max(1, 4)'\n\n\n====\nTODO\n====\n\n-------------------\nAvailable Operators\n-------------------\n\nOperators that Python allows to overridden\n\n\n======== ============== ===========\nOperator Method Current use\n======== ============== ===========\n\\+ __add__ sequences\n\\| __or__ selection\n[ ] __getitem__ repeat\n@ __matmul__ names and internalization\n< __lt__\n> __gt__\n<= __le__\n>= __ge__\n== __eq__\n!= __ne__\nis _is\nis not is_not\n\\- __sub__\n% __mod__\n\\* __mul__ zero or more, with provided separator\n\\** __pow__\n/ __truediv__\n// __floordiv__\n& __and__\n^ __xor__\n<< __lshift__\n>> __rshift__\nin __contains__\n======== ============== ===========\n\n\nUnary operators:\n\n======== =========== ===========\nOperator Method Current use\n======== =========== ===========\n~ __invert__ optional\nnot __not__\n\\- __neg__\n\\+ __pos__ zero or more\n======== =========== ===========\n\nAnd::\n\n () __call__ parse a string\n\n\n=========\nCopyright\n=========\n\nComber copyright 2025 Ray Wallace III\n\nThis library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, **version 2.1**.\n \nThis library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.\n \nYou should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA\n",
"bugtrack_url": null,
"license": "GNU LESSER GENERAL PUBLIC LICENSE\n Version 2.1, February 1999\n \n Copyright (C) 1991, 1999 Free Software Foundation, Inc.\n 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA\n Everyone is permitted to copy and distribute verbatim copies\n of this license document, but changing it is not allowed.\n \n [This is the first released version of the Lesser GPL. It also counts\n as the successor of the GNU Library Public License, version 2, hence\n the version number 2.1.]\n \n Preamble\n \n The licenses for most software are designed to take away your\n freedom to share and change it. By contrast, the GNU General Public\n Licenses are intended to guarantee your freedom to share and change\n free software--to make sure the software is free for all its users.\n \n This license, the Lesser General Public License, applies to some\n specially designated software packages--typically libraries--of the\n Free Software Foundation and other authors who decide to use it. You\n can use it too, but we suggest you first think carefully about whether\n this license or the ordinary General Public License is the better\n strategy to use in any particular case, based on the explanations below.\n \n When we speak of free software, we are referring to freedom of use,\n not price. Our General Public Licenses are designed to make sure that\n you have the freedom to distribute copies of free software (and charge\n for this service if you wish); that you receive source code or can get\n it if you want it; that you can change the software and use pieces of\n it in new free programs; and that you are informed that you can do\n these things.\n \n To protect your rights, we need to make restrictions that forbid\n distributors to deny you these rights or to ask you to surrender these\n rights. These restrictions translate to certain responsibilities for\n you if you distribute copies of the library or if you modify it.\n \n For example, if you distribute copies of the library, whether gratis\n or for a fee, you must give the recipients all the rights that we gave\n you. You must make sure that they, too, receive or can get the source\n code. If you link other code with the library, you must provide\n complete object files to the recipients, so that they can relink them\n with the library after making changes to the library and recompiling\n it. And you must show them these terms so they know their rights.\n \n We protect your rights with a two-step method: (1) we copyright the\n library, and (2) we offer you this license, which gives you legal\n permission to copy, distribute and/or modify the library.\n \n To protect each distributor, we want to make it very clear that\n there is no warranty for the free library. Also, if the library is\n modified by someone else and passed on, the recipients should know\n that what they have is not the original version, so that the original\n author's reputation will not be affected by problems that might be\n introduced by others.\n \n Finally, software patents pose a constant threat to the existence of\n any free program. We wish to make sure that a company cannot\n effectively restrict the users of a free program by obtaining a\n restrictive license from a patent holder. Therefore, we insist that\n any patent license obtained for a version of the library must be\n consistent with the full freedom of use specified in this license.\n \n Most GNU software, including some libraries, is covered by the\n ordinary GNU General Public License. This license, the GNU Lesser\n General Public License, applies to certain designated libraries, and\n is quite different from the ordinary General Public License. We use\n this license for certain libraries in order to permit linking those\n libraries into non-free programs.\n \n When a program is linked with a library, whether statically or using\n a shared library, the combination of the two is legally speaking a\n combined work, a derivative of the original library. The ordinary\n General Public License therefore permits such linking only if the\n entire combination fits its criteria of freedom. The Lesser General\n Public License permits more lax criteria for linking other code with\n the library.\n \n We call this license the \"Lesser\" General Public License because it\n does Less to protect the user's freedom than the ordinary General\n Public License. It also provides other free software developers Less\n of an advantage over competing non-free programs. These disadvantages\n are the reason we use the ordinary General Public License for many\n libraries. However, the Lesser license provides advantages in certain\n special circumstances.\n \n For example, on rare occasions, there may be a special need to\n encourage the widest possible use of a certain library, so that it becomes\n a de-facto standard. To achieve this, non-free programs must be\n allowed to use the library. A more frequent case is that a free\n library does the same job as widely used non-free libraries. In this\n case, there is little to gain by limiting the free library to free\n software only, so we use the Lesser General Public License.\n \n In other cases, permission to use a particular library in non-free\n programs enables a greater number of people to use a large body of\n free software. For example, permission to use the GNU C Library in\n non-free programs enables many more people to use the whole GNU\n operating system, as well as its variant, the GNU/Linux operating\n system.\n \n Although the Lesser General Public License is Less protective of the\n users' freedom, it does ensure that the user of a program that is\n linked with the Library has the freedom and the wherewithal to run\n that program using a modified version of the Library.\n \n The precise terms and conditions for copying, distribution and\n modification follow. Pay close attention to the difference between a\n \"work based on the library\" and a \"work that uses the library\". The\n former contains code derived from the library, whereas the latter must\n be combined with the library in order to run.\n \n GNU LESSER GENERAL PUBLIC LICENSE\n TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION\n \n 0. This License Agreement applies to any software library or other\n program which contains a notice placed by the copyright holder or\n other authorized party saying it may be distributed under the terms of\n this Lesser General Public License (also called \"this License\").\n Each licensee is addressed as \"you\".\n \n A \"library\" means a collection of software functions and/or data\n prepared so as to be conveniently linked with application programs\n (which use some of those functions and data) to form executables.\n \n The \"Library\", below, refers to any such software library or work\n which has been distributed under these terms. A \"work based on the\n Library\" means either the Library or any derivative work under\n copyright law: that is to say, a work containing the Library or a\n portion of it, either verbatim or with modifications and/or translated\n straightforwardly into another language. (Hereinafter, translation is\n included without limitation in the term \"modification\".)\n \n \"Source code\" for a work means the preferred form of the work for\n making modifications to it. For a library, complete source code means\n all the source code for all modules it contains, plus any associated\n interface definition files, plus the scripts used to control compilation\n and installation of the library.\n \n Activities other than copying, distribution and modification are not\n covered by this License; they are outside its scope. The act of\n running a program using the Library is not restricted, and output from\n such a program is covered only if its contents constitute a work based\n on the Library (independent of the use of the Library in a tool for\n writing it). Whether that is true depends on what the Library does\n and what the program that uses the Library does.\n \n 1. You may copy and distribute verbatim copies of the Library's\n complete source code as you receive it, in any medium, provided that\n you conspicuously and appropriately publish on each copy an\n appropriate copyright notice and disclaimer of warranty; keep intact\n all the notices that refer to this License and to the absence of any\n warranty; and distribute a copy of this License along with the\n Library.\n \n You may charge a fee for the physical act of transferring a copy,\n and you may at your option offer warranty protection in exchange for a\n fee.\n \n 2. You may modify your copy or copies of the Library or any portion\n of it, thus forming a work based on the Library, and copy and\n distribute such modifications or work under the terms of Section 1\n above, provided that you also meet all of these conditions:\n \n a) The modified work must itself be a software library.\n \n b) You must cause the files modified to carry prominent notices\n stating that you changed the files and the date of any change.\n \n c) You must cause the whole of the work to be licensed at no\n charge to all third parties under the terms of this License.\n \n d) If a facility in the modified Library refers to a function or a\n table of data to be supplied by an application program that uses\n the facility, other than as an argument passed when the facility\n is invoked, then you must make a good faith effort to ensure that,\n in the event an application does not supply such function or\n table, the facility still operates, and performs whatever part of\n its purpose remains meaningful.\n \n (For example, a function in a library to compute square roots has\n a purpose that is entirely well-defined independent of the\n application. Therefore, Subsection 2d requires that any\n application-supplied function or table used by this function must\n be optional: if the application does not supply it, the square\n root function must still compute square roots.)\n \n These requirements apply to the modified work as a whole. If\n identifiable sections of that work are not derived from the Library,\n and can be reasonably considered independent and separate works in\n themselves, then this License, and its terms, do not apply to those\n sections when you distribute them as separate works. But when you\n distribute the same sections as part of a whole which is a work based\n on the Library, the distribution of the whole must be on the terms of\n this License, whose permissions for other licensees extend to the\n entire whole, and thus to each and every part regardless of who wrote\n it.\n \n Thus, it is not the intent of this section to claim rights or contest\n your rights to work written entirely by you; rather, the intent is to\n exercise the right to control the distribution of derivative or\n collective works based on the Library.\n \n In addition, mere aggregation of another work not based on the Library\n with the Library (or with a work based on the Library) on a volume of\n a storage or distribution medium does not bring the other work under\n the scope of this License.\n \n 3. You may opt to apply the terms of the ordinary GNU General Public\n License instead of this License to a given copy of the Library. To do\n this, you must alter all the notices that refer to this License, so\n that they refer to the ordinary GNU General Public License, version 2,\n instead of to this License. (If a newer version than version 2 of the\n ordinary GNU General Public License has appeared, then you can specify\n that version instead if you wish.) Do not make any other change in\n these notices.\n \n Once this change is made in a given copy, it is irreversible for\n that copy, so the ordinary GNU General Public License applies to all\n subsequent copies and derivative works made from that copy.\n \n This option is useful when you wish to copy part of the code of\n the Library into a program that is not a library.\n \n 4. You may copy and distribute the Library (or a portion or\n derivative of it, under Section 2) in object code or executable form\n under the terms of Sections 1 and 2 above provided that you accompany\n it with the complete corresponding machine-readable source code, which\n must be distributed under the terms of Sections 1 and 2 above on a\n medium customarily used for software interchange.\n \n If distribution of object code is made by offering access to copy\n from a designated place, then offering equivalent access to copy the\n source code from the same place satisfies the requirement to\n distribute the source code, even though third parties are not\n compelled to copy the source along with the object code.\n \n 5. A program that contains no derivative of any portion of the\n Library, but is designed to work with the Library by being compiled or\n linked with it, is called a \"work that uses the Library\". Such a\n work, in isolation, is not a derivative work of the Library, and\n therefore falls outside the scope of this License.\n \n However, linking a \"work that uses the Library\" with the Library\n creates an executable that is a derivative of the Library (because it\n contains portions of the Library), rather than a \"work that uses the\n library\". The executable is therefore covered by this License.\n Section 6 states terms for distribution of such executables.\n \n When a \"work that uses the Library\" uses material from a header file\n that is part of the Library, the object code for the work may be a\n derivative work of the Library even though the source code is not.\n Whether this is true is especially significant if the work can be\n linked without the Library, or if the work is itself a library. The\n threshold for this to be true is not precisely defined by law.\n \n If such an object file uses only numerical parameters, data\n structure layouts and accessors, and small macros and small inline\n functions (ten lines or less in length), then the use of the object\n file is unrestricted, regardless of whether it is legally a derivative\n work. (Executables containing this object code plus portions of the\n Library will still fall under Section 6.)\n \n Otherwise, if the work is a derivative of the Library, you may\n distribute the object code for the work under the terms of Section 6.\n Any executables containing that work also fall under Section 6,\n whether or not they are linked directly with the Library itself.\n \n 6. As an exception to the Sections above, you may also combine or\n link a \"work that uses the Library\" with the Library to produce a\n work containing portions of the Library, and distribute that work\n under terms of your choice, provided that the terms permit\n modification of the work for the customer's own use and reverse\n engineering for debugging such modifications.\n \n You must give prominent notice with each copy of the work that the\n Library is used in it and that the Library and its use are covered by\n this License. You must supply a copy of this License. If the work\n during execution displays copyright notices, you must include the\n copyright notice for the Library among them, as well as a reference\n directing the user to the copy of this License. Also, you must do one\n of these things:\n \n a) Accompany the work with the complete corresponding\n machine-readable source code for the Library including whatever\n changes were used in the work (which must be distributed under\n Sections 1 and 2 above); and, if the work is an executable linked\n with the Library, with the complete machine-readable \"work that\n uses the Library\", as object code and/or source code, so that the\n user can modify the Library and then relink to produce a modified\n executable containing the modified Library. (It is understood\n that the user who changes the contents of definitions files in the\n Library will not necessarily be able to recompile the application\n to use the modified definitions.)\n \n b) Use a suitable shared library mechanism for linking with the\n Library. A suitable mechanism is one that (1) uses at run time a\n copy of the library already present on the user's computer system,\n rather than copying library functions into the executable, and (2)\n will operate properly with a modified version of the library, if\n the user installs one, as long as the modified version is\n interface-compatible with the version that the work was made with.\n \n c) Accompany the work with a written offer, valid for at\n least three years, to give the same user the materials\n specified in Subsection 6a, above, for a charge no more\n than the cost of performing this distribution.\n \n d) If distribution of the work is made by offering access to copy\n from a designated place, offer equivalent access to copy the above\n specified materials from the same place.\n \n e) Verify that the user has already received a copy of these\n materials or that you have already sent this user a copy.\n \n For an executable, the required form of the \"work that uses the\n Library\" must include any data and utility programs needed for\n reproducing the executable from it. However, as a special exception,\n the materials to be distributed need not include anything that is\n normally distributed (in either source or binary form) with the major\n components (compiler, kernel, and so on) of the operating system on\n which the executable runs, unless that component itself accompanies\n the executable.\n \n It may happen that this requirement contradicts the license\n restrictions of other proprietary libraries that do not normally\n accompany the operating system. Such a contradiction means you cannot\n use both them and the Library together in an executable that you\n distribute.\n \n 7. You may place library facilities that are a work based on the\n Library side-by-side in a single library together with other library\n facilities not covered by this License, and distribute such a combined\n library, provided that the separate distribution of the work based on\n the Library and of the other library facilities is otherwise\n permitted, and provided that you do these two things:\n \n a) Accompany the combined library with a copy of the same work\n based on the Library, uncombined with any other library\n facilities. This must be distributed under the terms of the\n Sections above.\n \n b) Give prominent notice with the combined library of the fact\n that part of it is a work based on the Library, and explaining\n where to find the accompanying uncombined form of the same work.\n \n 8. You may not copy, modify, sublicense, link with, or distribute\n the Library except as expressly provided under this License. Any\n attempt otherwise to copy, modify, sublicense, link with, or\n distribute the Library is void, and will automatically terminate your\n rights under this License. However, parties who have received copies,\n or rights, from you under this License will not have their licenses\n terminated so long as such parties remain in full compliance.\n \n 9. You are not required to accept this License, since you have not\n signed it. However, nothing else grants you permission to modify or\n distribute the Library or its derivative works. These actions are\n prohibited by law if you do not accept this License. Therefore, by\n modifying or distributing the Library (or any work based on the\n Library), you indicate your acceptance of this License to do so, and\n all its terms and conditions for copying, distributing or modifying\n the Library or works based on it.\n \n 10. Each time you redistribute the Library (or any work based on the\n Library), the recipient automatically receives a license from the\n original licensor to copy, distribute, link with or modify the Library\n subject to these terms and conditions. You may not impose any further\n restrictions on the recipients' exercise of the rights granted herein.\n You are not responsible for enforcing compliance by third parties with\n this License.\n \n 11. If, as a consequence of a court judgment or allegation of patent\n infringement or for any other reason (not limited to patent issues),\n conditions are imposed on you (whether by court order, agreement or\n otherwise) that contradict the conditions of this License, they do not\n excuse you from the conditions of this License. If you cannot\n distribute so as to satisfy simultaneously your obligations under this\n License and any other pertinent obligations, then as a consequence you\n may not distribute the Library at all. For example, if a patent\n license would not permit royalty-free redistribution of the Library by\n all those who receive copies directly or indirectly through you, then\n the only way you could satisfy both it and this License would be to\n refrain entirely from distribution of the Library.\n \n If any portion of this section is held invalid or unenforceable under any\n particular circumstance, the balance of the section is intended to apply,\n and the section as a whole is intended to apply in other circumstances.\n \n It is not the purpose of this section to induce you to infringe any\n patents or other property right claims or to contest validity of any\n such claims; this section has the sole purpose of protecting the\n integrity of the free software distribution system which is\n implemented by public license practices. Many people have made\n generous contributions to the wide range of software distributed\n through that system in reliance on consistent application of that\n system; it is up to the author/donor to decide if he or she is willing\n to distribute software through any other system and a licensee cannot\n impose that choice.\n \n This section is intended to make thoroughly clear what is believed to\n be a consequence of the rest of this License.\n \n 12. If the distribution and/or use of the Library is restricted in\n certain countries either by patents or by copyrighted interfaces, the\n original copyright holder who places the Library under this License may add\n an explicit geographical distribution limitation excluding those countries,\n so that distribution is permitted only in or among countries not thus\n excluded. In such case, this License incorporates the limitation as if\n written in the body of this License.\n \n 13. The Free Software Foundation may publish revised and/or new\n versions of the Lesser General Public License from time to time.\n Such new versions will be similar in spirit to the present version,\n but may differ in detail to address new problems or concerns.\n \n Each version is given a distinguishing version number. If the Library\n specifies a version number of this License which applies to it and\n \"any later version\", you have the option of following the terms and\n conditions either of that version or of any later version published by\n the Free Software Foundation. If the Library does not specify a\n license version number, you may choose any version ever published by\n the Free Software Foundation.\n \n 14. If you wish to incorporate parts of the Library into other free\n programs whose distribution conditions are incompatible with these,\n write to the author to ask for permission. For software which is\n copyrighted by the Free Software Foundation, write to the Free\n Software Foundation; we sometimes make exceptions for this. Our\n decision will be guided by the two goals of preserving the free status\n of all derivatives of our free software and of promoting the sharing\n and reuse of software generally.\n \n NO WARRANTY\n \n 15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO\n WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW.\n EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR\n OTHER PARTIES PROVIDE THE LIBRARY \"AS IS\" WITHOUT WARRANTY OF ANY\n KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE\n IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR\n PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE\n LIBRARY IS WITH YOU. SHOULD THE LIBRARY PROVE DEFECTIVE, YOU ASSUME\n THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.\n \n 16. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN\n WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY\n AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE LIABLE TO YOU\n FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR\n CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE\n LIBRARY (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING\n RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A\n FAILURE OF THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF\n SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH\n DAMAGES.\n \n END OF TERMS AND CONDITIONS\n \n How to Apply These Terms to Your New Libraries\n \n If you develop a new library, and you want it to be of the greatest\n possible use to the public, we recommend making it free software that\n everyone can redistribute and change. You can do so by permitting\n redistribution under these terms (or, alternatively, under the terms of the\n ordinary General Public License).\n \n To apply these terms, attach the following notices to the library. It is\n safest to attach them to the start of each source file to most effectively\n convey the exclusion of warranty; and each file should have at least the\n \"copyright\" line and a pointer to where the full notice is found.\n \n <one line to give the library's name and a brief idea of what it does.>\n Copyright (C) <year> <name of author>\n \n This library is free software; you can redistribute it and/or\n modify it under the terms of the GNU Lesser General Public\n License as published by the Free Software Foundation; either\n version 2.1 of the License, or (at your option) any later version.\n \n This library is distributed in the hope that it will be useful,\n but WITHOUT ANY WARRANTY; without even the implied warranty of\n MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU\n Lesser General Public License for more details.\n \n You should have received a copy of the GNU Lesser General Public\n License along with this library; if not, write to the Free Software\n Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301\n USA\n \n Also add information on how to contact you by electronic and paper mail.\n \n You should also get your employer (if you work as a programmer) or your\n school, if any, to sign a \"copyright disclaimer\" for the library, if\n necessary. Here is a sample; alter the names:\n \n Yoyodyne, Inc., hereby disclaims all copyright interest in the\n library `Frob' (a library for tweaking knobs) written by James Random\n Hacker.\n \n <signature of Ty Coon>, 1 April 1990\n Ty Coon, President of Vice\n \n That's all there is to it!\n ",
"summary": "Parser combinator library with a BNF-esque interface",
"version": "1.0.0",
"project_urls": {
"Homepage": "https://github.com/faboo/comber",
"Repository": "https://github.com/faboo/comber.git"
},
"split_keywords": [
"parser",
" combinator",
" parsing",
" compiler"
],
"urls": [
{
"comment_text": null,
"digests": {
"blake2b_256": "2f41f5d937d46fefd3a167ca432f0dec4e2659fe2cc02fed8ef7a259366815a2",
"md5": "3cfb36a17c27066e44fd049bb135889a",
"sha256": "ca302ab149a67506b578ff82282545f6645493e20c782d27aa712b30de50e91f"
},
"downloads": -1,
"filename": "comber-1.0.0-py3-none-any.whl",
"has_sig": false,
"md5_digest": "3cfb36a17c27066e44fd049bb135889a",
"packagetype": "bdist_wheel",
"python_version": "py3",
"requires_python": ">=3.10",
"size": 30843,
"upload_time": "2025-02-16T19:38:04",
"upload_time_iso_8601": "2025-02-16T19:38:04.802065Z",
"url": "https://files.pythonhosted.org/packages/2f/41/f5d937d46fefd3a167ca432f0dec4e2659fe2cc02fed8ef7a259366815a2/comber-1.0.0-py3-none-any.whl",
"yanked": false,
"yanked_reason": null
},
{
"comment_text": null,
"digests": {
"blake2b_256": "f2567eb99f97948d4ae2a0d990916200c791b691135ab3f0a1ac2bf719ce4f89",
"md5": "2f4b1ea784c6cd1e82fbf3535a3e367b",
"sha256": "fd02ff469b283f6d67578832bb5c1b31a1c09bce579bb3b1bdd2b8ecc8e6ebff"
},
"downloads": -1,
"filename": "comber-1.0.0.tar.gz",
"has_sig": false,
"md5_digest": "2f4b1ea784c6cd1e82fbf3535a3e367b",
"packagetype": "sdist",
"python_version": "source",
"requires_python": ">=3.10",
"size": 39623,
"upload_time": "2025-02-16T19:38:06",
"upload_time_iso_8601": "2025-02-16T19:38:06.506801Z",
"url": "https://files.pythonhosted.org/packages/f2/56/7eb99f97948d4ae2a0d990916200c791b691135ab3f0a1ac2bf719ce4f89/comber-1.0.0.tar.gz",
"yanked": false,
"yanked_reason": null
}
],
"upload_time": "2025-02-16 19:38:06",
"github": true,
"gitlab": false,
"bitbucket": false,
"codeberg": false,
"github_user": "faboo",
"github_project": "comber",
"github_not_found": true,
"lcname": "comber"
}
