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sugar-toolkit-gtk3/data/em.py
Marco Pesenti Gritti 79829dbbc2 empy is GPL
2007-06-24 15:04:52 +02:00

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#!/usr/bin/env python
#
# $Id: //projects/empy/em.py#146 $ $Date: 2003/10/27 $
# 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 2 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
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# 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, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
"""
A system for processing Python as markup embedded in text.
"""
__program__ = 'empy'
__version__ = '3.3'
__url__ = 'http://www.alcyone.com/software/empy/'
__author__ = 'Erik Max Francis <max@alcyone.com>'
__copyright__ = 'Copyright (C) 2002-2003 Erik Max Francis'
__license__ = 'LGPL'
import copy
import getopt
import os
import re
import string
import sys
import types
try:
# The equivalent of import cStringIO as StringIO.
import cStringIO
StringIO = cStringIO
del cStringIO
except ImportError:
import StringIO
# For backward compatibility, we can't assume these are defined.
False, True = 0, 1
# Some basic defaults.
FAILURE_CODE = 1
DEFAULT_PREFIX = '@'
DEFAULT_PSEUDOMODULE_NAME = 'empy'
DEFAULT_SCRIPT_NAME = '?'
SIGNIFICATOR_RE_SUFFIX = r"%(\S+)\s*(.*)\s*$"
SIGNIFICATOR_RE_STRING = DEFAULT_PREFIX + SIGNIFICATOR_RE_SUFFIX
BANGPATH = '#!'
DEFAULT_CHUNK_SIZE = 8192
DEFAULT_ERRORS = 'strict'
# Character information.
IDENTIFIER_FIRST_CHARS = '_abcdefghijklmnopqrstuvwxyz' \
'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
IDENTIFIER_CHARS = IDENTIFIER_FIRST_CHARS + '0123456789.'
ENDING_CHARS = {'(': ')', '[': ']', '{': '}'}
# Environment variable names.
OPTIONS_ENV = 'EMPY_OPTIONS'
PREFIX_ENV = 'EMPY_PREFIX'
PSEUDO_ENV = 'EMPY_PSEUDO'
FLATTEN_ENV = 'EMPY_FLATTEN'
RAW_ENV = 'EMPY_RAW_ERRORS'
INTERACTIVE_ENV = 'EMPY_INTERACTIVE'
BUFFERED_ENV = 'EMPY_BUFFERED_OUTPUT'
NO_OVERRIDE_ENV = 'EMPY_NO_OVERRIDE'
UNICODE_ENV = 'EMPY_UNICODE'
INPUT_ENCODING_ENV = 'EMPY_UNICODE_INPUT_ENCODING'
OUTPUT_ENCODING_ENV = 'EMPY_UNICODE_OUTPUT_ENCODING'
INPUT_ERRORS_ENV = 'EMPY_UNICODE_INPUT_ERRORS'
OUTPUT_ERRORS_ENV = 'EMPY_UNICODE_OUTPUT_ERRORS'
# Interpreter options.
BANGPATH_OPT = 'processBangpaths' # process bangpaths as comments?
BUFFERED_OPT = 'bufferedOutput' # fully buffered output?
RAW_OPT = 'rawErrors' # raw errors?
EXIT_OPT = 'exitOnError' # exit on error?
FLATTEN_OPT = 'flatten' # flatten pseudomodule namespace?
OVERRIDE_OPT = 'override' # override sys.stdout with proxy?
CALLBACK_OPT = 'noCallbackError' # is no custom callback an error?
# Usage info.
OPTION_INFO = [
("-V --version", "Print version and exit"),
("-h --help", "Print usage and exit"),
("-H --extended-help", "Print extended usage and exit"),
("-k --suppress-errors", "Do not exit on errors; go interactive"),
("-p --prefix=<char>", "Change prefix to something other than @"),
(" --no-prefix", "Do not do any markup processing at all"),
("-m --module=<name>", "Change the internal pseudomodule name"),
("-f --flatten", "Flatten the members of pseudmodule to start"),
("-r --raw-errors", "Show raw Python errors"),
("-i --interactive", "Go into interactive mode after processing"),
("-n --no-override-stdout", "Do not override sys.stdout with proxy"),
("-o --output=<filename>", "Specify file for output as write"),
("-a --append=<filename>", "Specify file for output as append"),
("-b --buffered-output", "Fully buffer output including open"),
(" --binary", "Treat the file as a binary"),
(" --chunk-size=<chunk>", "Use this chunk size for reading binaries"),
("-P --preprocess=<filename>", "Interpret EmPy file before main processing"),
("-I --import=<modules>", "Import Python modules before processing"),
("-D --define=<definition>", "Execute Python assignment statement"),
("-E --execute=<statement>", "Execute Python statement before processing"),
("-F --execute-file=<filename>", "Execute Python file before processing"),
(" --pause-at-end", "Prompt at the ending of processing"),
(" --relative-path", "Add path of EmPy script to sys.path"),
(" --no-callback-error", "Custom markup without callback is error"),
(" --no-bangpath-processing", "Suppress bangpaths as comments"),
("-u --unicode", "Enable Unicode subsystem (Python 2+ only)"),
(" --unicode-encoding=<e>", "Set both input and output encodings"),
(" --unicode-input-encoding=<e>", "Set input encoding"),
(" --unicode-output-encoding=<e>", "Set output encoding"),
(" --unicode-errors=<E>", "Set both input and output error handler"),
(" --unicode-input-errors=<E>", "Set input error handler"),
(" --unicode-output-errors=<E>", "Set output error handler"),
]
USAGE_NOTES = """\
Notes: Whitespace immediately inside parentheses of @(...) are
ignored. Whitespace immediately inside braces of @{...} are ignored,
unless ... spans multiple lines. Use @{ ... }@ to suppress newline
following expansion. Simple expressions ignore trailing dots; `@x.'
means `@(x).'. A #! at the start of a file is treated as a @#
comment."""
MARKUP_INFO = [
("@# ... NL", "Comment; remove everything up to newline"),
("@? NAME NL", "Set the current context name"),
("@! INTEGER NL", "Set the current context line number"),
("@ WHITESPACE", "Remove following whitespace; line continuation"),
("@\\ ESCAPE_CODE", "A C-style escape sequence"),
("@@", "Literal @; @ is escaped (duplicated prefix)"),
("@), @], @}", "Literal close parenthesis, bracket, brace"),
("@ STRING_LITERAL", "Replace with string literal contents"),
("@( EXPRESSION )", "Evaluate expression and substitute with str"),
("@( TEST [? THEN [! ELSE]] )", "If test is true, evaluate then, otherwise else"),
("@( TRY $ CATCH )", "Expand try expression, or catch if it raises"),
("@ SIMPLE_EXPRESSION", "Evaluate simple expression and substitute;\n"
"e.g., @x, @x.y, @f(a, b), @l[i], etc."),
("@` EXPRESSION `", "Evaluate expression and substitute with repr"),
("@: EXPRESSION : [DUMMY] :", "Evaluates to @:...:expansion:"),
("@{ STATEMENTS }", "Statements are executed for side effects"),
("@[ CONTROL ]", "Control markups: if E; elif E; for N in E;\n"
"while E; try; except E, N; finally; continue;\n"
"break; end X"),
("@%% KEY WHITESPACE VALUE NL", "Significator form of __KEY__ = VALUE"),
("@< CONTENTS >", "Custom markup; meaning provided by user"),
]
ESCAPE_INFO = [
("@\\0", "NUL, null"),
("@\\a", "BEL, bell"),
("@\\b", "BS, backspace"),
("@\\dDDD", "three-digit decimal code DDD"),
("@\\e", "ESC, escape"),
("@\\f", "FF, form feed"),
("@\\h", "DEL, delete"),
("@\\n", "LF, linefeed, newline"),
("@\\N{NAME}", "Unicode character named NAME"),
("@\\oOOO", "three-digit octal code OOO"),
("@\\qQQQQ", "four-digit quaternary code QQQQ"),
("@\\r", "CR, carriage return"),
("@\\s", "SP, space"),
("@\\t", "HT, horizontal tab"),
("@\\uHHHH", "16-bit hexadecimal Unicode HHHH"),
("@\\UHHHHHHHH", "32-bit hexadecimal Unicode HHHHHHHH"),
("@\\v", "VT, vertical tab"),
("@\\xHH", "two-digit hexadecimal code HH"),
("@\\z", "EOT, end of transmission"),
]
PSEUDOMODULE_INFO = [
("VERSION", "String representing EmPy version"),
("SIGNIFICATOR_RE_STRING", "Regular expression matching significators"),
("SIGNIFICATOR_RE_SUFFIX", "The above stub, lacking the prefix"),
("interpreter", "Currently-executing interpreter instance"),
("argv", "The EmPy script name and command line arguments"),
("args", "The command line arguments only"),
("identify()", "Identify top context as name, line"),
("setContextName(name)", "Set the name of the current context"),
("setContextLine(line)", "Set the line number of the current context"),
("atExit(callable)", "Invoke no-argument function at shutdown"),
("getGlobals()", "Retrieve this interpreter's globals"),
("setGlobals(dict)", "Set this interpreter's globals"),
("updateGlobals(dict)", "Merge dictionary into interpreter's globals"),
("clearGlobals()", "Start globals over anew"),
("saveGlobals([deep])", "Save a copy of the globals"),
("restoreGlobals([pop])", "Restore the most recently saved globals"),
("defined(name, [loc])", "Find if the name is defined"),
("evaluate(expression, [loc])", "Evaluate the expression"),
("serialize(expression, [loc])", "Evaluate and serialize the expression"),
("execute(statements, [loc])", "Execute the statements"),
("single(source, [loc])", "Execute the 'single' object"),
("atomic(name, value, [loc])", "Perform an atomic assignment"),
("assign(name, value, [loc])", "Perform an arbitrary assignment"),
("significate(key, [value])", "Significate the given key, value pair"),
("include(file, [loc])", "Include filename or file-like object"),
("expand(string, [loc])", "Explicitly expand string and return"),
("string(data, [name], [loc])", "Process string-like object"),
("quote(string)", "Quote prefixes in provided string and return"),
("flatten([keys])", "Flatten module contents into globals namespace"),
("getPrefix()", "Get current prefix"),
("setPrefix(char)", "Set new prefix"),
("stopDiverting()", "Stop diverting; data sent directly to output"),
("createDiversion(name)", "Create a diversion but do not divert to it"),
("retrieveDiversion(name)", "Retrieve the actual named diversion object"),
("startDiversion(name)", "Start diverting to given diversion"),
("playDiversion(name)", "Recall diversion and then eliminate it"),
("replayDiversion(name)", "Recall diversion but retain it"),
("purgeDiversion(name)", "Erase diversion"),
("playAllDiversions()", "Stop diverting and play all diversions in order"),
("replayAllDiversions()", "Stop diverting and replay all diversions"),
("purgeAllDiversions()", "Stop diverting and purge all diversions"),
("getFilter()", "Get current filter"),
("resetFilter()", "Reset filter; no filtering"),
("nullFilter()", "Install null filter"),
("setFilter(shortcut)", "Install new filter or filter chain"),
("attachFilter(shortcut)", "Attach single filter to end of current chain"),
("areHooksEnabled()", "Return whether or not hooks are enabled"),
("enableHooks()", "Enable hooks (default)"),
("disableHooks()", "Disable hook invocation"),
("getHooks()", "Get all the hooks"),
("clearHooks()", "Clear all hooks"),
("addHook(hook, [i])", "Register the hook (optionally insert)"),
("removeHook(hook)", "Remove an already-registered hook from name"),
("invokeHook(name_, ...)", "Manually invoke hook"),
("getCallback()", "Get interpreter callback"),
("registerCallback(callback)", "Register callback with interpreter"),
("deregisterCallback()", "Deregister callback from interpreter"),
("invokeCallback(contents)", "Invoke the callback directly"),
("Interpreter", "The interpreter class"),
]
ENVIRONMENT_INFO = [
(OPTIONS_ENV, "Specified options will be included"),
(PREFIX_ENV, "Specify the default prefix: -p <value>"),
(PSEUDO_ENV, "Specify name of pseudomodule: -m <value>"),
(FLATTEN_ENV, "Flatten empy pseudomodule if defined: -f"),
(RAW_ENV, "Show raw errors if defined: -r"),
(INTERACTIVE_ENV, "Enter interactive mode if defined: -i"),
(BUFFERED_ENV, "Fully buffered output if defined: -b"),
(NO_OVERRIDE_ENV, "Do not override sys.stdout if defined: -n"),
(UNICODE_ENV, "Enable Unicode subsystem: -n"),
(INPUT_ENCODING_ENV, "Unicode input encoding"),
(OUTPUT_ENCODING_ENV, "Unicode output encoding"),
(INPUT_ERRORS_ENV, "Unicode input error handler"),
(OUTPUT_ERRORS_ENV, "Unicode output error handler"),
]
class Error(Exception):
"""The base class for all EmPy errors."""
pass
EmpyError = EmPyError = Error # DEPRECATED
class DiversionError(Error):
"""An error related to diversions."""
pass
class FilterError(Error):
"""An error related to filters."""
pass
class StackUnderflowError(Error):
"""A stack underflow."""
pass
class SubsystemError(Error):
"""An error associated with the Unicode subsystem."""
pass
class FlowError(Error):
"""An exception related to control flow."""
pass
class ContinueFlow(FlowError):
"""A continue control flow."""
pass
class BreakFlow(FlowError):
"""A break control flow."""
pass
class ParseError(Error):
"""A parse error occurred."""
pass
class TransientParseError(ParseError):
"""A parse error occurred which may be resolved by feeding more data.
Such an error reaching the toplevel is an unexpected EOF error."""
pass
class MetaError(Exception):
"""A wrapper around a real Python exception for including a copy of
the context."""
def __init__(self, contexts, exc):
Exception.__init__(self, exc)
self.contexts = contexts
self.exc = exc
def __str__(self):
backtrace = map(lambda x: str(x), self.contexts)
return "%s: %s (%s)" % (self.exc.__class__, self.exc, \
(string.join(backtrace, ', ')))
class Subsystem:
"""The subsystem class defers file creation so that it can create
Unicode-wrapped files if desired (and possible)."""
def __init__(self):
self.useUnicode = False
self.inputEncoding = None
self.outputEncoding = None
self.errors = None
def initialize(self, inputEncoding=None, outputEncoding=None, \
inputErrors=None, outputErrors=None):
self.useUnicode = True
try:
unicode
import codecs
except (NameError, ImportError):
raise SubsystemError, "Unicode subsystem unavailable"
defaultEncoding = sys.getdefaultencoding()
if inputEncoding is None:
inputEncoding = defaultEncoding
self.inputEncoding = inputEncoding
if outputEncoding is None:
outputEncoding = defaultEncoding
self.outputEncoding = outputEncoding
if inputErrors is None:
inputErrors = DEFAULT_ERRORS
self.inputErrors = inputErrors
if outputErrors is None:
outputErrors = DEFAULT_ERRORS
self.outputErrors = outputErrors
def assertUnicode(self):
if not self.useUnicode:
raise SubsystemError, "Unicode subsystem unavailable"
def open(self, name, mode=None):
if self.useUnicode:
return self.unicodeOpen(name, mode)
else:
return self.defaultOpen(name, mode)
def defaultOpen(self, name, mode=None):
if mode is None:
mode = 'r'
return open(name, mode)
def unicodeOpen(self, name, mode=None):
import codecs
if mode is None:
mode = 'rb'
if mode.find('w') >= 0 or mode.find('a') >= 0:
encoding = self.outputEncoding
errors = self.outputErrors
else:
encoding = self.inputEncoding
errors = self.inputErrors
return codecs.open(name, mode, encoding, errors)
theSubsystem = Subsystem()
class Stack:
"""A simple stack that behaves as a sequence (with 0 being the top
of the stack, not the bottom)."""
def __init__(self, seq=None):
if seq is None:
seq = []
self.data = seq
def top(self):
"""Access the top element on the stack."""
try:
return self.data[-1]
except IndexError:
raise StackUnderflowError, "stack is empty for top"
def pop(self):
"""Pop the top element off the stack and return it."""
try:
return self.data.pop()
except IndexError:
raise StackUnderflowError, "stack is empty for pop"
def push(self, object):
"""Push an element onto the top of the stack."""
self.data.append(object)
def filter(self, function):
"""Filter the elements of the stack through the function."""
self.data = filter(function, self.data)
def purge(self):
"""Purge the stack."""
self.data = []
def clone(self):
"""Create a duplicate of this stack."""
return self.__class__(self.data[:])
def __nonzero__(self): return len(self.data) != 0
def __len__(self): return len(self.data)
def __getitem__(self, index): return self.data[-(index + 1)]
def __repr__(self):
return '<%s instance at 0x%x [%s]>' % \
(self.__class__, id(self), \
string.join(map(repr, self.data), ', '))
class AbstractFile:
"""An abstracted file that, when buffered, will totally buffer the
file, including even the file open."""
def __init__(self, filename, mode='w', buffered=False):
# The calls below might throw, so start off by marking this
# file as "done." This way destruction of a not-completely-
# initialized AbstractFile will generate no further errors.
self.done = True
self.filename = filename
self.mode = mode
self.buffered = buffered
if buffered:
self.bufferFile = StringIO.StringIO()
else:
self.bufferFile = theSubsystem.open(filename, mode)
# Okay, we got this far, so the AbstractFile is initialized.
# Flag it as "not done."
self.done = False
def __del__(self):
self.close()
def write(self, data):
self.bufferFile.write(data)
def writelines(self, data):
self.bufferFile.writelines(data)
def flush(self):
self.bufferFile.flush()
def close(self):
if not self.done:
self.commit()
self.done = True
def commit(self):
if self.buffered:
file = theSubsystem.open(self.filename, self.mode)
file.write(self.bufferFile.getvalue())
file.close()
else:
self.bufferFile.close()
def abort(self):
if self.buffered:
self.bufferFile = None
else:
self.bufferFile.close()
self.bufferFile = None
self.done = True
class Diversion:
"""The representation of an active diversion. Diversions act as
(writable) file objects, and then can be recalled either as pure
strings or (readable) file objects."""
def __init__(self):
self.file = StringIO.StringIO()
# These methods define the writable file-like interface for the
# diversion.
def write(self, data):
self.file.write(data)
def writelines(self, lines):
for line in lines:
self.write(line)
def flush(self):
self.file.flush()
def close(self):
self.file.close()
# These methods are specific to diversions.
def asString(self):
"""Return the diversion as a string."""
return self.file.getvalue()
def asFile(self):
"""Return the diversion as a file."""
return StringIO.StringIO(self.file.getvalue())
class Stream:
"""A wrapper around an (output) file object which supports
diversions and filtering."""
def __init__(self, file):
self.file = file
self.currentDiversion = None
self.diversions = {}
self.filter = file
self.done = False
def write(self, data):
if self.currentDiversion is None:
self.filter.write(data)
else:
self.diversions[self.currentDiversion].write(data)
def writelines(self, lines):
for line in lines:
self.write(line)
def flush(self):
self.filter.flush()
def close(self):
if not self.done:
self.undivertAll(True)
self.filter.close()
self.done = True
def shortcut(self, shortcut):
"""Take a filter shortcut and translate it into a filter, returning
it. Sequences don't count here; these should be detected
independently."""
if shortcut == 0:
return NullFilter()
elif type(shortcut) is types.FunctionType or \
type(shortcut) is types.BuiltinFunctionType or \
type(shortcut) is types.BuiltinMethodType or \
type(shortcut) is types.LambdaType:
return FunctionFilter(shortcut)
elif type(shortcut) is types.StringType:
return StringFilter(filter)
elif type(shortcut) is types.DictType:
raise NotImplementedError, "mapping filters not yet supported"
else:
# Presume it's a plain old filter.
return shortcut
def last(self):
"""Find the last filter in the current filter chain, or None if
there are no filters installed."""
if self.filter is None:
return None
thisFilter, lastFilter = self.filter, None
while thisFilter is not None and thisFilter is not self.file:
lastFilter = thisFilter
thisFilter = thisFilter.next()
return lastFilter
def install(self, shortcut=None):
"""Install a new filter; None means no filter. Handle all the
special shortcuts for filters here."""
# Before starting, execute a flush.
self.filter.flush()
if shortcut is None or shortcut == [] or shortcut == ():
# Shortcuts for "no filter."
self.filter = self.file
else:
if type(shortcut) in (types.ListType, types.TupleType):
shortcuts = list(shortcut)
else:
shortcuts = [shortcut]
# Run through the shortcut filter names, replacing them with
# full-fledged instances of Filter.
filters = []
for shortcut in shortcuts:
filters.append(self.shortcut(shortcut))
if len(filters) > 1:
# If there's more than one filter provided, chain them
# together.
lastFilter = None
for filter in filters:
if lastFilter is not None:
lastFilter.attach(filter)
lastFilter = filter
lastFilter.attach(self.file)
self.filter = filters[0]
else:
# If there's only one filter, assume that it's alone or it's
# part of a chain that has already been manually chained;
# just find the end.
filter = filters[0]
lastFilter = filter.last()
lastFilter.attach(self.file)
self.filter = filter
def attach(self, shortcut):
"""Attached a solitary filter (no sequences allowed here) at the
end of the current filter chain."""
lastFilter = self.last()
if lastFilter is None:
# Just install it from scratch if there is no active filter.
self.install(shortcut)
else:
# Attach the last filter to this one, and this one to the file.
filter = self.shortcut(shortcut)
lastFilter.attach(filter)
filter.attach(self.file)
def revert(self):
"""Reset any current diversions."""
self.currentDiversion = None
def create(self, name):
"""Create a diversion if one does not already exist, but do not
divert to it yet."""
if name is None:
raise DiversionError, "diversion name must be non-None"
if not self.diversions.has_key(name):
self.diversions[name] = Diversion()
def retrieve(self, name):
"""Retrieve the given diversion."""
if name is None:
raise DiversionError, "diversion name must be non-None"
if self.diversions.has_key(name):
return self.diversions[name]
else:
raise DiversionError, "nonexistent diversion: %s" % name
def divert(self, name):
"""Start diverting."""
if name is None:
raise DiversionError, "diversion name must be non-None"
self.create(name)
self.currentDiversion = name
def undivert(self, name, purgeAfterwards=False):
"""Undivert a particular diversion."""
if name is None:
raise DiversionError, "diversion name must be non-None"
if self.diversions.has_key(name):
diversion = self.diversions[name]
self.filter.write(diversion.asString())
if purgeAfterwards:
self.purge(name)
else:
raise DiversionError, "nonexistent diversion: %s" % name
def purge(self, name):
"""Purge the specified diversion."""
if name is None:
raise DiversionError, "diversion name must be non-None"
if self.diversions.has_key(name):
del self.diversions[name]
if self.currentDiversion == name:
self.currentDiversion = None
def undivertAll(self, purgeAfterwards=True):
"""Undivert all pending diversions."""
if self.diversions:
self.revert() # revert before undiverting!
names = self.diversions.keys()
names.sort()
for name in names:
self.undivert(name)
if purgeAfterwards:
self.purge(name)
def purgeAll(self):
"""Eliminate all existing diversions."""
if self.diversions:
self.diversions = {}
self.currentDiversion = None
class NullFile:
"""A simple class that supports all the file-like object methods
but simply does nothing at all."""
def __init__(self): pass
def write(self, data): pass
def writelines(self, lines): pass
def flush(self): pass
def close(self): pass
class UncloseableFile:
"""A simple class which wraps around a delegate file-like object
and lets everything through except close calls."""
def __init__(self, delegate):
self.delegate = delegate
def write(self, data):
self.delegate.write(data)
def writelines(self, lines):
self.delegate.writelines(data)
def flush(self):
self.delegate.flush()
def close(self):
"""Eat this one."""
pass
class ProxyFile:
"""The proxy file object that is intended to take the place of
sys.stdout. The proxy can manage a stack of file objects it is
writing to, and an underlying raw file object."""
def __init__(self, bottom):
self.stack = Stack()
self.bottom = bottom
def current(self):
"""Get the current stream to write to."""
if self.stack:
return self.stack[-1][1]
else:
return self.bottom
def push(self, interpreter):
self.stack.push((interpreter, interpreter.stream()))
def pop(self, interpreter):
result = self.stack.pop()
assert interpreter is result[0]
def clear(self, interpreter):
self.stack.filter(lambda x, i=interpreter: x[0] is not i)
def write(self, data):
self.current().write(data)
def writelines(self, lines):
self.current().writelines(lines)
def flush(self):
self.current().flush()
def close(self):
"""Close the current file. If the current file is the bottom, then
close it and dispose of it."""
current = self.current()
if current is self.bottom:
self.bottom = None
current.close()
def _testProxy(self): pass
class Filter:
"""An abstract filter."""
def __init__(self):
if self.__class__ is Filter:
raise NotImplementedError
self.sink = None
def next(self):
"""Return the next filter/file-like object in the sequence, or None."""
return self.sink
def write(self, data):
"""The standard write method; this must be overridden in subclasses."""
raise NotImplementedError
def writelines(self, lines):
"""Standard writelines wrapper."""
for line in lines:
self.write(line)
def _flush(self):
"""The _flush method should always flush the sink and should not
be overridden."""
self.sink.flush()
def flush(self):
"""The flush method can be overridden."""
self._flush()
def close(self):
"""Close the filter. Do an explicit flush first, then close the
sink."""
self.flush()
self.sink.close()
def attach(self, filter):
"""Attach a filter to this one."""
if self.sink is not None:
# If it's already attached, detach it first.
self.detach()
self.sink = filter
def detach(self):
"""Detach a filter from its sink."""
self.flush()
self._flush() # do a guaranteed flush to just to be safe
self.sink = None
def last(self):
"""Find the last filter in this chain."""
this, last = self, self
while this is not None:
last = this
this = this.next()
return last
class NullFilter(Filter):
"""A filter that never sends any output to its sink."""
def write(self, data): pass
class FunctionFilter(Filter):
"""A filter that works simply by pumping its input through a
function which maps strings into strings."""
def __init__(self, function):
Filter.__init__(self)
self.function = function
def write(self, data):
self.sink.write(self.function(data))
class StringFilter(Filter):
"""A filter that takes a translation string (256 characters) and
filters any incoming data through it."""
def __init__(self, table):
if not (type(table) == types.StringType and len(table) == 256):
raise FilterError, "table must be 256-character string"
Filter.__init__(self)
self.table = table
def write(self, data):
self.sink.write(string.translate(data, self.table))
class BufferedFilter(Filter):
"""A buffered filter is one that doesn't modify the source data
sent to the sink, but instead holds it for a time. The standard
variety only sends the data along when it receives a flush
command."""
def __init__(self):
Filter.__init__(self)
self.buffer = ''
def write(self, data):
self.buffer = self.buffer + data
def flush(self):
if self.buffer:
self.sink.write(self.buffer)
self._flush()
class SizeBufferedFilter(BufferedFilter):
"""A size-buffered filter only in fixed size chunks (excepting the
final chunk)."""
def __init__(self, bufferSize):
BufferedFilter.__init__(self)
self.bufferSize = bufferSize
def write(self, data):
BufferedFilter.write(self, data)
while len(self.buffer) > self.bufferSize:
chunk, self.buffer = \
self.buffer[:self.bufferSize], self.buffer[self.bufferSize:]
self.sink.write(chunk)
class LineBufferedFilter(BufferedFilter):
"""A line-buffered filter only lets data through when it sees
whole lines."""
def __init__(self):
BufferedFilter.__init__(self)
def write(self, data):
BufferedFilter.write(self, data)
chunks = string.split(self.buffer, '\n')
for chunk in chunks[:-1]:
self.sink.write(chunk + '\n')
self.buffer = chunks[-1]
class MaximallyBufferedFilter(BufferedFilter):
"""A maximally-buffered filter only lets its data through on the final
close. It ignores flushes."""
def __init__(self):
BufferedFilter.__init__(self)
def flush(self): pass
def close(self):
if self.buffer:
BufferedFilter.flush(self)
self.sink.close()
class Context:
"""An interpreter context, which encapsulates a name, an input
file object, and a parser object."""
DEFAULT_UNIT = 'lines'
def __init__(self, name, line=0, units=DEFAULT_UNIT):
self.name = name
self.line = line
self.units = units
self.pause = False
def bump(self, quantity=1):
if self.pause:
self.pause = False
else:
self.line = self.line + quantity
def identify(self):
return self.name, self.line
def __str__(self):
if self.units == self.DEFAULT_UNIT:
return "%s:%s" % (self.name, self.line)
else:
return "%s:%s[%s]" % (self.name, self.line, self.units)
class Hook:
"""The base class for implementing hooks."""
def __init__(self):
self.interpreter = None
def register(self, interpreter):
self.interpreter = interpreter
def deregister(self, interpreter):
if interpreter is not self.interpreter:
raise Error, "hook not associated with this interpreter"
self.interpreter = None
def push(self):
self.interpreter.push()
def pop(self):
self.interpreter.pop()
def null(self): pass
def atStartup(self): pass
def atReady(self): pass
def atFinalize(self): pass
def atShutdown(self): pass
def atParse(self, scanner, locals): pass
def atToken(self, token): pass
def atHandle(self, meta): pass
def atInteract(self): pass
def beforeInclude(self, name, file, locals): pass
def afterInclude(self): pass
def beforeExpand(self, string, locals): pass
def afterExpand(self, result): pass
def beforeFile(self, name, file, locals): pass
def afterFile(self): pass
def beforeBinary(self, name, file, chunkSize, locals): pass
def afterBinary(self): pass
def beforeString(self, name, string, locals): pass
def afterString(self): pass
def beforeQuote(self, string): pass
def afterQuote(self, result): pass
def beforeEscape(self, string, more): pass
def afterEscape(self, result): pass
def beforeControl(self, type, rest, locals): pass
def afterControl(self): pass
def beforeSignificate(self, key, value, locals): pass
def afterSignificate(self): pass
def beforeAtomic(self, name, value, locals): pass
def afterAtomic(self): pass
def beforeMulti(self, name, values, locals): pass
def afterMulti(self): pass
def beforeImport(self, name, locals): pass
def afterImport(self): pass
def beforeClause(self, catch, locals): pass
def afterClause(self, exception, variable): pass
def beforeSerialize(self, expression, locals): pass
def afterSerialize(self): pass
def beforeDefined(self, name, locals): pass
def afterDefined(self, result): pass
def beforeLiteral(self, text): pass
def afterLiteral(self): pass
def beforeEvaluate(self, expression, locals): pass
def afterEvaluate(self, result): pass
def beforeExecute(self, statements, locals): pass
def afterExecute(self): pass
def beforeSingle(self, source, locals): pass
def afterSingle(self): pass
class VerboseHook(Hook):
"""A verbose hook that reports all information received by the
hook interface. This class dynamically scans the Hook base class
to ensure that all hook methods are properly represented."""
EXEMPT_ATTRIBUTES = ['register', 'deregister', 'push', 'pop']
def __init__(self, output=sys.stderr):
Hook.__init__(self)
self.output = output
self.indent = 0
class FakeMethod:
"""This is a proxy method-like object."""
def __init__(self, hook, name):
self.hook = hook
self.name = name
def __call__(self, **keywords):
self.hook.output.write("%s%s: %s\n" % \
(' ' * self.hook.indent, \
self.name, repr(keywords)))
for attribute in dir(Hook):
if attribute[:1] != '_' and \
attribute not in self.EXEMPT_ATTRIBUTES:
self.__dict__[attribute] = FakeMethod(self, attribute)
class Token:
"""An element of expansion."""
def run(self, interpreter, locals):
raise NotImplementedError
def string(self):
raise NotImplementedError
def __str__(self): return self.string()
class NullToken(Token):
"""A chunk of data not containing markups."""
def __init__(self, data):
self.data = data
def run(self, interpreter, locals):
interpreter.write(self.data)
def string(self):
return self.data
class ExpansionToken(Token):
"""A token that involves an expansion."""
def __init__(self, prefix, first):
self.prefix = prefix
self.first = first
def scan(self, scanner):
pass
def run(self, interpreter, locals):
pass
class WhitespaceToken(ExpansionToken):
"""A whitespace markup."""
def string(self):
return '%s%s' % (self.prefix, self.first)
class LiteralToken(ExpansionToken):
"""A literal markup."""
def run(self, interpreter, locals):
interpreter.write(self.first)
def string(self):
return '%s%s' % (self.prefix, self.first)
class PrefixToken(ExpansionToken):
"""A prefix markup."""
def run(self, interpreter, locals):
interpreter.write(interpreter.prefix)
def string(self):
return self.prefix * 2
class CommentToken(ExpansionToken):
"""A comment markup."""
def scan(self, scanner):
loc = scanner.find('\n')
if loc >= 0:
self.comment = scanner.chop(loc, 1)
else:
raise TransientParseError, "comment expects newline"
def string(self):
return '%s#%s\n' % (self.prefix, self.comment)
class ContextNameToken(ExpansionToken):
"""A context name change markup."""
def scan(self, scanner):
loc = scanner.find('\n')
if loc >= 0:
self.name = string.strip(scanner.chop(loc, 1))
else:
raise TransientParseError, "context name expects newline"
def run(self, interpreter, locals):
context = interpreter.context()
context.name = self.name
class ContextLineToken(ExpansionToken):
"""A context line change markup."""
def scan(self, scanner):
loc = scanner.find('\n')
if loc >= 0:
try:
self.line = int(scanner.chop(loc, 1))
except ValueError:
raise ParseError, "context line requires integer"
else:
raise TransientParseError, "context line expects newline"
def run(self, interpreter, locals):
context = interpreter.context()
context.line = self.line
context.pause = True
class EscapeToken(ExpansionToken):
"""An escape markup."""
def scan(self, scanner):
try:
code = scanner.chop(1)
result = None
if code in '()[]{}\'\"\\': # literals
result = code
elif code == '0': # NUL
result = '\x00'
elif code == 'a': # BEL
result = '\x07'
elif code == 'b': # BS
result = '\x08'
elif code == 'd': # decimal code
decimalCode = scanner.chop(3)
result = chr(string.atoi(decimalCode, 10))
elif code == 'e': # ESC
result = '\x1b'
elif code == 'f': # FF
result = '\x0c'
elif code == 'h': # DEL
result = '\x7f'
elif code == 'n': # LF (newline)
result = '\x0a'
elif code == 'N': # Unicode character name
theSubsystem.assertUnicode()
import unicodedata
if scanner.chop(1) != '{':
raise ParseError, r"Unicode name escape should be \N{...}"
i = scanner.find('}')
name = scanner.chop(i, 1)
try:
result = unicodedata.lookup(name)
except KeyError:
raise SubsystemError, \
"unknown Unicode character name: %s" % name
elif code == 'o': # octal code
octalCode = scanner.chop(3)
result = chr(string.atoi(octalCode, 8))
elif code == 'q': # quaternary code
quaternaryCode = scanner.chop(4)
result = chr(string.atoi(quaternaryCode, 4))
elif code == 'r': # CR
result = '\x0d'
elif code in 's ': # SP
result = ' '
elif code == 't': # HT
result = '\x09'
elif code in 'u': # Unicode 16-bit hex literal
theSubsystem.assertUnicode()
hexCode = scanner.chop(4)
result = unichr(string.atoi(hexCode, 16))
elif code in 'U': # Unicode 32-bit hex literal
theSubsystem.assertUnicode()
hexCode = scanner.chop(8)
result = unichr(string.atoi(hexCode, 16))
elif code == 'v': # VT
result = '\x0b'
elif code == 'x': # hexadecimal code
hexCode = scanner.chop(2)
result = chr(string.atoi(hexCode, 16))
elif code == 'z': # EOT
result = '\x04'
elif code == '^': # control character
controlCode = string.upper(scanner.chop(1))
if controlCode >= '@' and controlCode <= '`':
result = chr(ord(controlCode) - ord('@'))
elif controlCode == '?':
result = '\x7f'
else:
raise ParseError, "invalid escape control code"
else:
raise ParseError, "unrecognized escape code"
assert result is not None
self.code = result
except ValueError:
raise ParseError, "invalid numeric escape code"
def run(self, interpreter, locals):
interpreter.write(self.code)
def string(self):
return '%s\\x%02x' % (self.prefix, ord(self.code))
class SignificatorToken(ExpansionToken):
"""A significator markup."""
def scan(self, scanner):
loc = scanner.find('\n')
if loc >= 0:
line = scanner.chop(loc, 1)
if not line:
raise ParseError, "significator must have nonblank key"
if line[0] in ' \t\v\n':
raise ParseError, "no whitespace between % and key"
# Work around a subtle CPython-Jython difference by stripping
# the string before splitting it: 'a '.split(None, 1) has two
# elements in Jython 2.1).
fields = string.split(string.strip(line), None, 1)
if len(fields) == 2 and fields[1] == '':
fields.pop()
self.key = fields[0]
if len(fields) < 2:
fields.append(None)
self.key, self.valueCode = fields
else:
raise TransientParseError, "significator expects newline"
def run(self, interpreter, locals):
value = self.valueCode
if value is not None:
value = interpreter.evaluate(string.strip(value), locals)
interpreter.significate(self.key, value)
def string(self):
if self.valueCode is None:
return '%s%%%s\n' % (self.prefix, self.key)
else:
return '%s%%%s %s\n' % (self.prefix, self.key, self.valueCode)
class ExpressionToken(ExpansionToken):
"""An expression markup."""
def scan(self, scanner):
z = scanner.complex('(', ')', 0)
try:
q = scanner.next('$', 0, z, True)
except ParseError:
q = z
try:
i = scanner.next('?', 0, q, True)
try:
j = scanner.next('!', i, q, True)
except ParseError:
try:
j = scanner.next(':', i, q, True) # DEPRECATED
except ParseError:
j = q
except ParseError:
i = j = q
code = scanner.chop(z, 1)
self.testCode = code[:i]
self.thenCode = code[i + 1:j]
self.elseCode = code[j + 1:q]
self.exceptCode = code[q + 1:z]
def run(self, interpreter, locals):
try:
result = interpreter.evaluate(self.testCode, locals)
if self.thenCode:
if result:
result = interpreter.evaluate(self.thenCode, locals)
else:
if self.elseCode:
result = interpreter.evaluate(self.elseCode, locals)
else:
result = None
except SyntaxError:
# Don't catch syntax errors; let them through.
raise
except:
if self.exceptCode:
result = interpreter.evaluate(self.exceptCode, locals)
else:
raise
if result is not None:
interpreter.write(str(result))
def string(self):
result = self.testCode
if self.thenCode:
result = result + '?' + self.thenCode
if self.elseCode:
result = result + '!' + self.elseCode
if self.exceptCode:
result = result + '$' + self.exceptCode
return '%s(%s)' % (self.prefix, result)
class StringLiteralToken(ExpansionToken):
"""A string token markup."""
def scan(self, scanner):
scanner.retreat()
assert scanner[0] == self.first
i = scanner.quote()
self.literal = scanner.chop(i)
def run(self, interpreter, locals):
interpreter.literal(self.literal)
def string(self):
return '%s%s' % (self.prefix, self.literal)
class SimpleExpressionToken(ExpansionToken):
"""A simple expression markup."""
def scan(self, scanner):
i = scanner.simple()
self.code = self.first + scanner.chop(i)
def run(self, interpreter, locals):
interpreter.serialize(self.code, locals)
def string(self):
return '%s%s' % (self.prefix, self.code)
class ReprToken(ExpansionToken):
"""A repr markup."""
def scan(self, scanner):
i = scanner.next('`', 0)
self.code = scanner.chop(i, 1)
def run(self, interpreter, locals):
interpreter.write(repr(interpreter.evaluate(self.code, locals)))
def string(self):
return '%s`%s`' % (self.prefix, self.code)
class InPlaceToken(ExpansionToken):
"""An in-place markup."""
def scan(self, scanner):
i = scanner.next(':', 0)
j = scanner.next(':', i + 1)
self.code = scanner.chop(i, j - i + 1)
def run(self, interpreter, locals):
interpreter.write("%s:%s:" % (interpreter.prefix, self.code))
try:
interpreter.serialize(self.code, locals)
finally:
interpreter.write(":")
def string(self):
return '%s:%s::' % (self.prefix, self.code)
class StatementToken(ExpansionToken):
"""A statement markup."""
def scan(self, scanner):
i = scanner.complex('{', '}', 0)
self.code = scanner.chop(i, 1)
def run(self, interpreter, locals):
interpreter.execute(self.code, locals)
def string(self):
return '%s{%s}' % (self.prefix, self.code)
class CustomToken(ExpansionToken):
"""A custom markup."""
def scan(self, scanner):
i = scanner.complex('<', '>', 0)
self.contents = scanner.chop(i, 1)
def run(self, interpreter, locals):
interpreter.invokeCallback(self.contents)
def string(self):
return '%s<%s>' % (self.prefix, self.contents)
class ControlToken(ExpansionToken):
"""A control token."""
PRIMARY_TYPES = ['if', 'for', 'while', 'try', 'def']
SECONDARY_TYPES = ['elif', 'else', 'except', 'finally']
TERTIARY_TYPES = ['continue', 'break']
GREEDY_TYPES = ['if', 'elif', 'for', 'while', 'def', 'end']
END_TYPES = ['end']
IN_RE = re.compile(r"\bin\b")
def scan(self, scanner):
scanner.acquire()
i = scanner.complex('[', ']', 0)
self.contents = scanner.chop(i, 1)
fields = string.split(string.strip(self.contents), ' ', 1)
if len(fields) > 1:
self.type, self.rest = fields
else:
self.type = fields[0]
self.rest = None
self.subtokens = []
if self.type in self.GREEDY_TYPES and self.rest is None:
raise ParseError, "control '%s' needs arguments" % self.type
if self.type in self.PRIMARY_TYPES:
self.subscan(scanner, self.type)
self.kind = 'primary'
elif self.type in self.SECONDARY_TYPES:
self.kind = 'secondary'
elif self.type in self.TERTIARY_TYPES:
self.kind = 'tertiary'
elif self.type in self.END_TYPES:
self.kind = 'end'
else:
raise ParseError, "unknown control markup: '%s'" % self.type
scanner.release()
def subscan(self, scanner, primary):
"""Do a subscan for contained tokens."""
while True:
token = scanner.one()
if token is None:
raise TransientParseError, \
"control '%s' needs more tokens" % primary
if isinstance(token, ControlToken) and \
token.type in self.END_TYPES:
if token.rest != primary:
raise ParseError, \
"control must end with 'end %s'" % primary
break
self.subtokens.append(token)
def build(self, allowed=None):
"""Process the list of subtokens and divide it into a list of
2-tuples, consisting of the dividing tokens and the list of
subtokens that follow them. If allowed is specified, it will
represent the list of the only secondary markup types which
are allowed."""
if allowed is None:
allowed = SECONDARY_TYPES
result = []
latest = []
result.append((self, latest))
for subtoken in self.subtokens:
if isinstance(subtoken, ControlToken) and \
subtoken.kind == 'secondary':
if subtoken.type not in allowed:
raise ParseError, \
"control unexpected secondary: '%s'" % subtoken.type
latest = []
result.append((subtoken, latest))
else:
latest.append(subtoken)
return result
def run(self, interpreter, locals):
interpreter.invoke('beforeControl', type=self.type, rest=self.rest, \
locals=locals)
if self.type == 'if':
info = self.build(['elif', 'else'])
elseTokens = None
if info[-1][0].type == 'else':
elseTokens = info.pop()[1]
for secondary, subtokens in info:
if secondary.type not in ('if', 'elif'):
raise ParseError, \
"control 'if' unexpected secondary: '%s'" % secondary.type
if interpreter.evaluate(secondary.rest, locals):
self.subrun(subtokens, interpreter, locals)
break
else:
if elseTokens:
self.subrun(elseTokens, interpreter, locals)
elif self.type == 'for':
sides = self.IN_RE.split(self.rest, 1)
if len(sides) != 2:
raise ParseError, "control expected 'for x in seq'"
iterator, sequenceCode = sides
info = self.build(['else'])
elseTokens = None
if info[-1][0].type == 'else':
elseTokens = info.pop()[1]
if len(info) != 1:
raise ParseError, "control 'for' expects at most one 'else'"
sequence = interpreter.evaluate(sequenceCode, locals)
for element in sequence:
try:
interpreter.assign(iterator, element, locals)
self.subrun(info[0][1], interpreter, locals)
except ContinueFlow:
continue
except BreakFlow:
break
else:
if elseTokens:
self.subrun(elseTokens, interpreter, locals)
elif self.type == 'while':
testCode = self.rest
info = self.build(['else'])
elseTokens = None
if info[-1][0].type == 'else':
elseTokens = info.pop()[1]
if len(info) != 1:
raise ParseError, "control 'while' expects at most one 'else'"
atLeastOnce = False
while True:
try:
if not interpreter.evaluate(testCode, locals):
break
atLeastOnce = True
self.subrun(info[0][1], interpreter, locals)
except ContinueFlow:
continue
except BreakFlow:
break
if not atLeastOnce and elseTokens:
self.subrun(elseTokens, interpreter, locals)
elif self.type == 'try':
info = self.build(['except', 'finally'])
if len(info) == 1:
raise ParseError, "control 'try' needs 'except' or 'finally'"
type = info[-1][0].type
if type == 'except':
for secondary, _tokens in info[1:]:
if secondary.type != 'except':
raise ParseError, \
"control 'try' cannot have 'except' and 'finally'"
else:
assert type == 'finally'
if len(info) != 2:
raise ParseError, \
"control 'try' can only have one 'finally'"
if type == 'except':
try:
self.subrun(info[0][1], interpreter, locals)
except FlowError:
raise
except Exception, e:
for secondary, tokens in info[1:]:
exception, variable = interpreter.clause(secondary.rest)
if variable is not None:
interpreter.assign(variable, e)
if isinstance(e, exception):
self.subrun(tokens, interpreter, locals)
break
else:
raise
else:
try:
self.subrun(info[0][1], interpreter, locals)
finally:
self.subrun(info[1][1], interpreter, locals)
elif self.type == 'continue':
raise ContinueFlow, "control 'continue' without 'for', 'while'"
elif self.type == 'break':
raise BreakFlow, "control 'break' without 'for', 'while'"
elif self.type == 'def':
signature = self.rest
definition = self.substring()
code = 'def %s:\n' \
' r"""%s"""\n' \
' return %s.expand(r"""%s""", locals())\n' % \
(signature, definition, interpreter.pseudo, definition)
interpreter.execute(code, locals)
elif self.type == 'end':
raise ParseError, "control 'end' requires primary markup"
else:
raise ParseError, \
"control '%s' cannot be at this level" % self.type
interpreter.invoke('afterControl')
def subrun(self, tokens, interpreter, locals):
"""Execute a sequence of tokens."""
for token in tokens:
token.run(interpreter, locals)
def substring(self):
return string.join(map(str, self.subtokens), '')
def string(self):
if self.kind == 'primary':
return '%s[%s]%s%s[end %s]' % \
(self.prefix, self.contents, self.substring(), \
self.prefix, self.type)
else:
return '%s[%s]' % (self.prefix, self.contents)
class Scanner:
"""A scanner holds a buffer for lookahead parsing and has the
ability to scan for special symbols and indicators in that
buffer."""
# This is the token mapping table that maps first characters to
# token classes.
TOKEN_MAP = [
(None, PrefixToken),
(' \t\v\r\n', WhitespaceToken),
(')]}', LiteralToken),
('\\', EscapeToken),
('#', CommentToken),
('?', ContextNameToken),
('!', ContextLineToken),
('%', SignificatorToken),
('(', ExpressionToken),
(IDENTIFIER_FIRST_CHARS, SimpleExpressionToken),
('\'\"', StringLiteralToken),
('`', ReprToken),
(':', InPlaceToken),
('[', ControlToken),
('{', StatementToken),
('<', CustomToken),
]
def __init__(self, prefix, data=''):
self.prefix = prefix
self.pointer = 0
self.buffer = data
self.lock = 0
def __nonzero__(self): return self.pointer < len(self.buffer)
def __len__(self): return len(self.buffer) - self.pointer
def __getitem__(self, index): return self.buffer[self.pointer + index]
def __getslice__(self, start, stop):
if stop > len(self):
stop = len(self)
return self.buffer[self.pointer + start:self.pointer + stop]
def advance(self, count=1):
"""Advance the pointer count characters."""
self.pointer = self.pointer + count
def retreat(self, count=1):
self.pointer = self.pointer - count
if self.pointer < 0:
raise ParseError, "can't retreat back over synced out chars"
def set(self, data):
"""Start the scanner digesting a new batch of data; start the pointer
over from scratch."""
self.pointer = 0
self.buffer = data
def feed(self, data):
"""Feed some more data to the scanner."""
self.buffer = self.buffer + data
def chop(self, count=None, slop=0):
"""Chop the first count + slop characters off the front, and return
the first count. If count is not specified, then return
everything."""
if count is None:
assert slop == 0
count = len(self)
if count > len(self):
raise TransientParseError, "not enough data to read"
result = self[:count]
self.advance(count + slop)
return result
def acquire(self):
"""Lock the scanner so it doesn't destroy data on sync."""
self.lock = self.lock + 1
def release(self):
"""Unlock the scanner."""
self.lock = self.lock - 1
def sync(self):
"""Sync up the buffer with the read head."""
if self.lock == 0 and self.pointer != 0:
self.buffer = self.buffer[self.pointer:]
self.pointer = 0
def unsync(self):
"""Undo changes; reset the read head."""
if self.pointer != 0:
self.lock = 0
self.pointer = 0
def rest(self):
"""Get the remainder of the buffer."""
return self[:]
def read(self, i=0, count=1):
"""Read count chars starting from i; raise a transient error if
there aren't enough characters remaining."""
if len(self) < i + count:
raise TransientParseError, "need more data to read"
else:
return self[i:i + count]
def check(self, i, archetype=None):
"""Scan for the next single or triple quote, with the specified
archetype. Return the found quote or None."""
quote = None
if self[i] in '\'\"':
quote = self[i]
if len(self) - i < 3:
for j in range(i, len(self)):
if self[i] == quote:
return quote
else:
raise TransientParseError, "need to scan for rest of quote"
if self[i + 1] == self[i + 2] == quote:
quote = quote * 3
if quote is not None:
if archetype is None:
return quote
else:
if archetype == quote:
return quote
elif len(archetype) < len(quote) and archetype[0] == quote[0]:
return archetype
else:
return None
else:
return None
def find(self, sub, start=0, end=None):
"""Find the next occurrence of the character, or return -1."""
if end is not None:
return string.find(self.rest(), sub, start, end)
else:
return string.find(self.rest(), sub, start)
def last(self, char, start=0, end=None):
"""Find the first character that is _not_ the specified character."""
if end is None:
end = len(self)
i = start
while i < end:
if self[i] != char:
return i
i = i + 1
else:
raise TransientParseError, "expecting other than %s" % char
def next(self, target, start=0, end=None, mandatory=False):
"""Scan for the next occurrence of one of the characters in
the target string; optionally, make the scan mandatory."""
if mandatory:
assert end is not None
quote = None
if end is None:
end = len(self)
i = start
while i < end:
newQuote = self.check(i, quote)
if newQuote:
if newQuote == quote:
quote = None
else:
quote = newQuote
i = i + len(newQuote)
else:
c = self[i]
if quote:
if c == '\\':
i = i + 1
else:
if c in target:
return i
i = i + 1
else:
if mandatory:
raise ParseError, "expecting %s, not found" % target
else:
raise TransientParseError, "expecting ending character"
def quote(self, start=0, end=None, mandatory=False):
"""Scan for the end of the next quote."""
assert self[start] in '\'\"'
quote = self.check(start)
if end is None:
end = len(self)
i = start + len(quote)
while i < end:
newQuote = self.check(i, quote)
if newQuote:
i = i + len(newQuote)
if newQuote == quote:
return i
else:
c = self[i]
if c == '\\':
i = i + 1
i = i + 1
else:
if mandatory:
raise ParseError, "expecting end of string literal"
else:
raise TransientParseError, "expecting end of string literal"
def nested(self, enter, exit, start=0, end=None):
"""Scan from i for an ending sequence, respecting entries and exits
only."""
depth = 0
if end is None:
end = len(self)
i = start
while i < end:
c = self[i]
if c == enter:
depth = depth + 1
elif c == exit:
depth = depth - 1
if depth < 0:
return i
i = i + 1
else:
raise TransientParseError, "expecting end of complex expression"
def complex(self, enter, exit, start=0, end=None, skip=None):
"""Scan from i for an ending sequence, respecting quotes,
entries and exits."""
quote = None
depth = 0
if end is None:
end = len(self)
last = None
i = start
while i < end:
newQuote = self.check(i, quote)
if newQuote:
if newQuote == quote:
quote = None
else:
quote = newQuote
i = i + len(newQuote)
else:
c = self[i]
if quote:
if c == '\\':
i = i + 1
else:
if skip is None or last != skip:
if c == enter:
depth = depth + 1
elif c == exit:
depth = depth - 1
if depth < 0:
return i
last = c
i = i + 1
else:
raise TransientParseError, "expecting end of complex expression"
def word(self, start=0):
"""Scan from i for a simple word."""
length = len(self)
i = start
while i < length:
if not self[i] in IDENTIFIER_CHARS:
return i
i = i + 1
else:
raise TransientParseError, "expecting end of word"
def phrase(self, start=0):
"""Scan from i for a phrase (e.g., 'word', 'f(a, b, c)', 'a[i]', or
combinations like 'x[i](a)'."""
# Find the word.
i = self.word(start)
while i < len(self) and self[i] in '([{':
enter = self[i]
if enter == '{':
raise ParseError, "curly braces can't open simple expressions"
exit = ENDING_CHARS[enter]
i = self.complex(enter, exit, i + 1) + 1
return i
def simple(self, start=0):
"""Scan from i for a simple expression, which consists of one
more phrases separated by dots."""
i = self.phrase(start)
length = len(self)
while i < length and self[i] == '.':
i = self.phrase(i)
# Make sure we don't end with a trailing dot.
while i > 0 and self[i - 1] == '.':
i = i - 1
return i
def one(self):
"""Parse and return one token, or None if the scanner is empty."""
if not self:
return None
if not self.prefix:
loc = -1
else:
loc = self.find(self.prefix)
if loc < 0:
# If there's no prefix in the buffer, then set the location to
# the end so the whole thing gets processed.
loc = len(self)
if loc == 0:
# If there's a prefix at the beginning of the buffer, process
# an expansion.
prefix = self.chop(1)
assert prefix == self.prefix
first = self.chop(1)
if first == self.prefix:
first = None
for firsts, factory in self.TOKEN_MAP:
if firsts is None:
if first is None:
break
elif first in firsts:
break
else:
raise ParseError, "unknown markup: %s%s" % (self.prefix, first)
token = factory(self.prefix, first)
try:
token.scan(self)
except TransientParseError:
# If a transient parse error occurs, reset the buffer pointer
# so we can (conceivably) try again later.
self.unsync()
raise
else:
# Process everything up to loc as a null token.
data = self.chop(loc)
token = NullToken(data)
self.sync()
return token
class Interpreter:
"""An interpreter can process chunks of EmPy code."""
# Constants.
VERSION = __version__
SIGNIFICATOR_RE_SUFFIX = SIGNIFICATOR_RE_SUFFIX
SIGNIFICATOR_RE_STRING = None
# Types.
Interpreter = None # define this below to prevent a circular reference
Hook = Hook # DEPRECATED
Filter = Filter # DEPRECATED
NullFilter = NullFilter # DEPRECATED
FunctionFilter = FunctionFilter # DEPRECATED
StringFilter = StringFilter # DEPRECATED
BufferedFilter = BufferedFilter # DEPRECATED
SizeBufferedFilter = SizeBufferedFilter # DEPRECATED
LineBufferedFilter = LineBufferedFilter # DEPRECATED
MaximallyBufferedFilter = MaximallyBufferedFilter # DEPRECATED
# Tables.
ESCAPE_CODES = {0x00: '0', 0x07: 'a', 0x08: 'b', 0x1b: 'e', 0x0c: 'f', \
0x7f: 'h', 0x0a: 'n', 0x0d: 'r', 0x09: 't', 0x0b: 'v', \
0x04: 'z'}
ASSIGN_TOKEN_RE = re.compile(r"[_a-zA-Z][_a-zA-Z0-9]*|\(|\)|,")
DEFAULT_OPTIONS = {BANGPATH_OPT: True,
BUFFERED_OPT: False,
RAW_OPT: False,
EXIT_OPT: True,
FLATTEN_OPT: False,
OVERRIDE_OPT: True,
CALLBACK_OPT: False}
_wasProxyInstalled = False # was a proxy installed?
# Construction, initialization, destruction.
def __init__(self, output=None, argv=None, prefix=DEFAULT_PREFIX, \
pseudo=None, options=None, globals=None, hooks=None):
self.interpreter = self # DEPRECATED
# Set up the stream.
if output is None:
output = UncloseableFile(sys.__stdout__)
self.output = output
self.prefix = prefix
if pseudo is None:
pseudo = DEFAULT_PSEUDOMODULE_NAME
self.pseudo = pseudo
if argv is None:
argv = [DEFAULT_SCRIPT_NAME]
self.argv = argv
self.args = argv[1:]
if options is None:
options = {}
self.options = options
# Initialize any hooks.
self.hooksEnabled = None # special sentinel meaning "false until added"
self.hooks = []
if hooks is None:
hooks = []
for hook in hooks:
self.register(hook)
# Initialize callback.
self.callback = None
# Finalizers.
self.finals = []
# The interpreter stacks.
self.contexts = Stack()
self.streams = Stack()
# Now set up the globals.
self.globals = globals
self.fix()
self.history = Stack()
# Install a proxy stdout if one hasn't been already.
self.installProxy()
# Finally, reset the state of all the stacks.
self.reset()
# Okay, now flatten the namespaces if that option has been set.
if self.options.get(FLATTEN_OPT, False):
self.flatten()
# Set up old pseudomodule attributes.
if prefix is None:
self.SIGNIFICATOR_RE_STRING = None
else:
self.SIGNIFICATOR_RE_STRING = prefix + self.SIGNIFICATOR_RE_SUFFIX
self.Interpreter = self.__class__
# Done. Now declare that we've started up.
self.invoke('atStartup')
def __del__(self):
self.shutdown()
def __repr__(self):
return '<%s pseudomodule/interpreter at 0x%x>' % \
(self.pseudo, id(self))
def ready(self):
"""Declare the interpreter ready for normal operations."""
self.invoke('atReady')
def fix(self):
"""Reset the globals, stamping in the pseudomodule."""
if self.globals is None:
self.globals = {}
# Make sure that there is no collision between two interpreters'
# globals.
if self.globals.has_key(self.pseudo):
if self.globals[self.pseudo] is not self:
raise Error, "interpreter globals collision"
self.globals[self.pseudo] = self
def unfix(self):
"""Remove the pseudomodule (if present) from the globals."""
UNWANTED_KEYS = [self.pseudo, '__builtins__']
for unwantedKey in UNWANTED_KEYS:
if self.globals.has_key(unwantedKey):
del self.globals[unwantedKey]
def update(self, other):
"""Update the current globals dictionary with another dictionary."""
self.globals.update(other)
self.fix()
def clear(self):
"""Clear out the globals dictionary with a brand new one."""
self.globals = {}
self.fix()
def save(self, deep=True):
if deep:
copyMethod = copy.deepcopy
else:
copyMethod = copy.copy
"""Save a copy of the current globals on the history stack."""
self.unfix()
self.history.push(copyMethod(self.globals))
self.fix()
def restore(self, destructive=True):
"""Restore the topmost historic globals."""
if destructive:
fetchMethod = self.history.pop
else:
fetchMethod = self.history.top
self.unfix()
self.globals = fetchMethod()
self.fix()
def shutdown(self):
"""Declare this interpreting session over; close the stream file
object. This method is idempotent."""
if self.streams is not None:
try:
self.finalize()
self.invoke('atShutdown')
while self.streams:
stream = self.streams.pop()
stream.close()
finally:
self.streams = None
def ok(self):
"""Is the interpreter still active?"""
return self.streams is not None
# Writeable file-like methods.
def write(self, data):
self.stream().write(data)
def writelines(self, stuff):
self.stream().writelines(stuff)
def flush(self):
self.stream().flush()
def close(self):
self.shutdown()
# Stack-related activity.
def context(self):
return self.contexts.top()
def stream(self):
return self.streams.top()
def reset(self):
self.contexts.purge()
self.streams.purge()
self.streams.push(Stream(self.output))
if self.options.get(OVERRIDE_OPT, True):
sys.stdout.clear(self)
def push(self):
if self.options.get(OVERRIDE_OPT, True):
sys.stdout.push(self)
def pop(self):
if self.options.get(OVERRIDE_OPT, True):
sys.stdout.pop(self)
# Higher-level operations.
def include(self, fileOrFilename, locals=None):
"""Do an include pass on a file or filename."""
if type(fileOrFilename) is types.StringType:
# Either it's a string representing a filename ...
filename = fileOrFilename
name = filename
file = theSubsystem.open(filename, 'r')
else:
# ... or a file object.
file = fileOrFilename
name = "<%s>" % str(file.__class__)
self.invoke('beforeInclude', name=name, file=file, locals=locals)
self.file(file, name, locals)
self.invoke('afterInclude')
def expand(self, data, locals=None):
"""Do an explicit expansion on a subordinate stream."""
outFile = StringIO.StringIO()
stream = Stream(outFile)
self.invoke('beforeExpand', string=data, locals=locals)
self.streams.push(stream)
try:
self.string(data, '<expand>', locals)
stream.flush()
expansion = outFile.getvalue()
self.invoke('afterExpand', result=expansion)
return expansion
finally:
self.streams.pop()
def quote(self, data):
"""Quote the given string so that if it were expanded it would
evaluate to the original."""
self.invoke('beforeQuote', string=data)
scanner = Scanner(self.prefix, data)
result = []
i = 0
try:
j = scanner.next(self.prefix, i)
result.append(data[i:j])
result.append(self.prefix * 2)
i = j + 1
except TransientParseError:
pass
result.append(data[i:])
result = string.join(result, '')
self.invoke('afterQuote', result=result)
return result
def escape(self, data, more=''):
"""Escape a string so that nonprintable characters are replaced
with compatible EmPy expansions."""
self.invoke('beforeEscape', string=data, more=more)
result = []
for char in data:
if char < ' ' or char > '~':
charOrd = ord(char)
if Interpreter.ESCAPE_CODES.has_key(charOrd):
result.append(self.prefix + '\\' + \
Interpreter.ESCAPE_CODES[charOrd])
else:
result.append(self.prefix + '\\x%02x' % charOrd)
elif char in more:
result.append(self.prefix + '\\' + char)
else:
result.append(char)
result = string.join(result, '')
self.invoke('afterEscape', result=result)
return result
# Processing.
def wrap(self, callable, args):
"""Wrap around an application of a callable and handle errors.
Return whether no error occurred."""
try:
apply(callable, args)
self.reset()
return True
except KeyboardInterrupt, e:
# Handle keyboard interrupts specially: we should always exit
# from these.
self.fail(e, True)
except Exception, e:
# A standard exception (other than a keyboard interrupt).
self.fail(e)
except:
# If we get here, then either it's an exception not derived from
# Exception or it's a string exception, so get the error type
# from the sys module.
e = sys.exc_type
self.fail(e)
# An error occurred if we leak through to here, so do cleanup.
self.reset()
return False
def interact(self):
"""Perform interaction."""
self.invoke('atInteract')
done = False
while not done:
result = self.wrap(self.file, (sys.stdin, '<interact>'))
if self.options.get(EXIT_OPT, True):
done = True
else:
if result:
done = True
else:
self.reset()
def fail(self, error, fatal=False):
"""Handle an actual error that occurred."""
if self.options.get(BUFFERED_OPT, False):
try:
self.output.abort()
except AttributeError:
# If the output file object doesn't have an abort method,
# something got mismatched, but it's too late to do
# anything about it now anyway, so just ignore it.
pass
meta = self.meta(error)
self.handle(meta)
if self.options.get(RAW_OPT, False):
raise
if fatal or self.options.get(EXIT_OPT, True):
sys.exit(FAILURE_CODE)
def file(self, file, name='<file>', locals=None):
"""Parse the entire contents of a file-like object, line by line."""
context = Context(name)
self.contexts.push(context)
self.invoke('beforeFile', name=name, file=file, locals=locals)
scanner = Scanner(self.prefix)
first = True
done = False
while not done:
self.context().bump()
line = file.readline()
if first:
if self.options.get(BANGPATH_OPT, True) and self.prefix:
# Replace a bangpath at the beginning of the first line
# with an EmPy comment.
if string.find(line, BANGPATH) == 0:
line = self.prefix + '#' + line[2:]
first = False
if line:
scanner.feed(line)
else:
done = True
self.safe(scanner, done, locals)
self.invoke('afterFile')
self.contexts.pop()
def binary(self, file, name='<binary>', chunkSize=0, locals=None):
"""Parse the entire contents of a file-like object, in chunks."""
if chunkSize <= 0:
chunkSize = DEFAULT_CHUNK_SIZE
context = Context(name, units='bytes')
self.contexts.push(context)
self.invoke('beforeBinary', name=name, file=file, \
chunkSize=chunkSize, locals=locals)
scanner = Scanner(self.prefix)
done = False
while not done:
chunk = file.read(chunkSize)
if chunk:
scanner.feed(chunk)
else:
done = True
self.safe(scanner, done, locals)
self.context().bump(len(chunk))
self.invoke('afterBinary')
self.contexts.pop()
def string(self, data, name='<string>', locals=None):
"""Parse a string."""
context = Context(name)
self.contexts.push(context)
self.invoke('beforeString', name=name, string=data, locals=locals)
context.bump()
scanner = Scanner(self.prefix, data)
self.safe(scanner, True, locals)
self.invoke('afterString')
self.contexts.pop()
def safe(self, scanner, final=False, locals=None):
"""Do a protected parse. Catch transient parse errors; if
final is true, then make a final pass with a terminator,
otherwise ignore the transient parse error (more data is
pending)."""
try:
self.parse(scanner, locals)
except TransientParseError:
if final:
# If the buffer doesn't end with a newline, try tacking on
# a dummy terminator.
buffer = scanner.rest()
if buffer and buffer[-1] != '\n':
scanner.feed(self.prefix + '\n')
# A TransientParseError thrown from here is a real parse
# error.
self.parse(scanner, locals)
def parse(self, scanner, locals=None):
"""Parse and run as much from this scanner as possible."""
self.invoke('atParse', scanner=scanner, locals=locals)
while True:
token = scanner.one()
if token is None:
break
self.invoke('atToken', token=token)
token.run(self, locals)
# Medium-level evaluation and execution.
def tokenize(self, name):
"""Take an lvalue string and return a name or a (possibly recursive)
list of names."""
result = []
stack = [result]
for garbage in self.ASSIGN_TOKEN_RE.split(name):
garbage = string.strip(garbage)
if garbage:
raise ParseError, "unexpected assignment token: '%s'" % garbage
tokens = self.ASSIGN_TOKEN_RE.findall(name)
# While processing, put a None token at the start of any list in which
# commas actually appear.
for token in tokens:
if token == '(':
stack.append([])
elif token == ')':
top = stack.pop()
if len(top) == 1:
top = top[0] # no None token means that it's not a 1-tuple
elif top[0] is None:
del top[0] # remove the None token for real tuples
stack[-1].append(top)
elif token == ',':
if len(stack[-1]) == 1:
stack[-1].insert(0, None)
else:
stack[-1].append(token)
# If it's a 1-tuple at the top level, turn it into a real subsequence.
if result and result[0] is None:
result = [result[1:]]
if len(result) == 1:
return result[0]
else:
return result
def significate(self, key, value=None, locals=None):
"""Declare a significator."""
self.invoke('beforeSignificate', key=key, value=value, locals=locals)
name = '__%s__' % key
self.atomic(name, value, locals)
self.invoke('afterSignificate')
def atomic(self, name, value, locals=None):
"""Do an atomic assignment."""
self.invoke('beforeAtomic', name=name, value=value, locals=locals)
if locals is None:
self.globals[name] = value
else:
locals[name] = value
self.invoke('afterAtomic')
def multi(self, names, values, locals=None):
"""Do a (potentially recursive) assignment."""
self.invoke('beforeMulti', names=names, values=values, locals=locals)
# No zip in 1.5, so we have to do it manually.
i = 0
try:
values = tuple(values)
except TypeError:
raise TypeError, "unpack non-sequence"
if len(names) != len(values):
raise ValueError, "unpack tuple of wrong size"
for i in range(len(names)):
name = names[i]
if type(name) is types.StringType:
self.atomic(name, values[i], locals)
else:
self.multi(name, values[i], locals)
self.invoke('afterMulti')
def assign(self, name, value, locals=None):
"""Do a potentially complex (including tuple unpacking) assignment."""
left = self.tokenize(name)
# The return value of tokenize can either be a string or a list of
# (lists of) strings.
if type(left) is types.StringType:
self.atomic(left, value, locals)
else:
self.multi(left, value, locals)
def import_(self, name, locals=None):
"""Do an import."""
self.invoke('beforeImport', name=name, locals=locals)
self.execute('import %s' % name, locals)
self.invoke('afterImport')
def clause(self, catch, locals=None):
"""Given the string representation of an except clause, turn it into
a 2-tuple consisting of the class name, and either a variable name
or None."""
self.invoke('beforeClause', catch=catch, locals=locals)
if catch is None:
exceptionCode, variable = None, None
elif string.find(catch, ',') >= 0:
exceptionCode, variable = string.split(string.strip(catch), ',', 1)
variable = string.strip(variable)
else:
exceptionCode, variable = string.strip(catch), None
if not exceptionCode:
exception = Exception
else:
exception = self.evaluate(exceptionCode, locals)
self.invoke('afterClause', exception=exception, variable=variable)
return exception, variable
def serialize(self, expression, locals=None):
"""Do an expansion, involving evaluating an expression, then
converting it to a string and writing that string to the
output if the evaluation is not None."""
self.invoke('beforeSerialize', expression=expression, locals=locals)
result = self.evaluate(expression, locals)
if result is not None:
self.write(str(result))
self.invoke('afterSerialize')
def defined(self, name, locals=None):
"""Return a Boolean indicating whether or not the name is
defined either in the locals or the globals."""
self.invoke('beforeDefined', name=name, local=local)
if locals is not None:
if locals.has_key(name):
result = True
else:
result = False
elif self.globals.has_key(name):
result = True
else:
result = False
self.invoke('afterDefined', result=result)
def literal(self, text):
"""Process a string literal."""
self.invoke('beforeLiteral', text=text)
self.serialize(text)
self.invoke('afterLiteral')
# Low-level evaluation and execution.
def evaluate(self, expression, locals=None):
"""Evaluate an expression."""
if expression in ('1', 'True'): return True
if expression in ('0', 'False'): return False
self.push()
try:
self.invoke('beforeEvaluate', \
expression=expression, locals=locals)
if locals is not None:
result = eval(expression, self.globals, locals)
else:
result = eval(expression, self.globals)
self.invoke('afterEvaluate', result=result)
return result
finally:
self.pop()
def execute(self, statements, locals=None):
"""Execute a statement."""
# If there are any carriage returns (as opposed to linefeeds/newlines)
# in the statements code, then remove them. Even on DOS/Windows
# platforms,
if string.find(statements, '\r') >= 0:
statements = string.replace(statements, '\r', '')
# If there are no newlines in the statements code, then strip any
# leading or trailing whitespace.
if string.find(statements, '\n') < 0:
statements = string.strip(statements)
self.push()
try:
self.invoke('beforeExecute', \
statements=statements, locals=locals)
if locals is not None:
exec statements in self.globals, locals
else:
exec statements in self.globals
self.invoke('afterExecute')
finally:
self.pop()
def single(self, source, locals=None):
"""Execute an expression or statement, just as if it were
entered into the Python interactive interpreter."""
self.push()
try:
self.invoke('beforeSingle', \
source=source, locals=locals)
code = compile(source, '<single>', 'single')
if locals is not None:
exec code in self.globals, locals
else:
exec code in self.globals
self.invoke('afterSingle')
finally:
self.pop()
# Hooks.
def register(self, hook, prepend=False):
"""Register the provided hook."""
hook.register(self)
if self.hooksEnabled is None:
# A special optimization so that hooks can be effectively
# disabled until one is added or they are explicitly turned on.
self.hooksEnabled = True
if prepend:
self.hooks.insert(0, hook)
else:
self.hooks.append(hook)
def deregister(self, hook):
"""Remove an already registered hook."""
hook.deregister(self)
self.hooks.remove(hook)
def invoke(self, _name, **keywords):
"""Invoke the hook(s) associated with the hook name, should they
exist."""
if self.hooksEnabled:
for hook in self.hooks:
hook.push()
try:
method = getattr(hook, _name)
apply(method, (), keywords)
finally:
hook.pop()
def finalize(self):
"""Execute any remaining final routines."""
self.push()
self.invoke('atFinalize')
try:
# Pop them off one at a time so they get executed in reverse
# order and we remove them as they're executed in case something
# bad happens.
while self.finals:
final = self.finals.pop()
final()
finally:
self.pop()
# Error handling.
def meta(self, exc=None):
"""Construct a MetaError for the interpreter's current state."""
return MetaError(self.contexts.clone(), exc)
def handle(self, meta):
"""Handle a MetaError."""
first = True
self.invoke('atHandle', meta=meta)
for context in meta.contexts:
if first:
if meta.exc is not None:
desc = "error: %s: %s" % (meta.exc.__class__, meta.exc)
else:
desc = "error"
else:
desc = "from this context"
first = False
sys.stderr.write('%s: %s\n' % (context, desc))
def installProxy(self):
"""Install a proxy if necessary."""
# Unfortunately, there's no surefire way to make sure that installing
# a sys.stdout proxy is idempotent, what with different interpreters
# running from different modules. The best we can do here is to try
# manipulating the proxy's test function ...
try:
sys.stdout._testProxy()
except AttributeError:
# ... if the current stdout object doesn't have one, then check
# to see if we think _this_ particularly Interpreter class has
# installed it before ...
if Interpreter._wasProxyInstalled:
# ... and if so, we have a proxy problem.
raise Error, "interpreter stdout proxy lost"
else:
# Otherwise, install the proxy and set the flag.
sys.stdout = ProxyFile(sys.stdout)
Interpreter._wasProxyInstalled = True
#
# Pseudomodule routines.
#
# Identification.
def identify(self):
"""Identify the topmost context with a 2-tuple of the name and
line number."""
return self.context().identify()
def atExit(self, callable):
"""Register a function to be called at exit."""
self.finals.append(callable)
# Context manipulation.
def pushContext(self, name='<unnamed>', line=0):
"""Create a new context and push it."""
self.contexts.push(Context(name, line))
def popContext(self):
"""Pop the top context."""
self.contexts.pop()
def setContextName(self, name):
"""Set the name of the topmost context."""
context = self.context()
context.name = name
def setContextLine(self, line):
"""Set the name of the topmost context."""
context = self.context()
context.line = line
setName = setContextName # DEPRECATED
setLine = setContextLine # DEPRECATED
# Globals manipulation.
def getGlobals(self):
"""Retrieve the globals."""
return self.globals
def setGlobals(self, globals):
"""Set the globals to the specified dictionary."""
self.globals = globals
self.fix()
def updateGlobals(self, otherGlobals):
"""Merge another mapping object into this interpreter's globals."""
self.update(otherGlobals)
def clearGlobals(self):
"""Clear out the globals with a brand new dictionary."""
self.clear()
def saveGlobals(self, deep=True):
"""Save a copy of the globals off onto the history stack."""
self.save(deep)
def restoreGlobals(self, destructive=True):
"""Restore the most recently saved copy of the globals."""
self.restore(destructive)
# Hook support.
def areHooksEnabled(self):
"""Return whether or not hooks are presently enabled."""
if self.hooksEnabled is None:
return True
else:
return self.hooksEnabled
def enableHooks(self):
"""Enable hooks."""
self.hooksEnabled = True
def disableHooks(self):
"""Disable hooks."""
self.hooksEnabled = False
def getHooks(self):
"""Get the current hooks."""
return self.hooks[:]
def clearHooks(self):
"""Clear all hooks."""
self.hooks = []
def addHook(self, hook, prepend=False):
"""Add a new hook; optionally insert it rather than appending it."""
self.register(hook, prepend)
def removeHook(self, hook):
"""Remove a preexisting hook."""
self.deregister(hook)
def invokeHook(self, _name, **keywords):
"""Manually invoke a hook."""
apply(self.invoke, (_name,), keywords)
# Callbacks.
def getCallback(self):
"""Get the callback registered with this interpreter, or None."""
return self.callback
def registerCallback(self, callback):
"""Register a custom markup callback with this interpreter."""
self.callback = callback
def deregisterCallback(self):
"""Remove any previously registered callback with this interpreter."""
self.callback = None
def invokeCallback(self, contents):
"""Invoke the callback."""
if self.callback is None:
if self.options.get(CALLBACK_OPT, False):
raise Error, "custom markup invoked with no defined callback"
else:
self.callback(contents)
# Pseudomodule manipulation.
def flatten(self, keys=None):
"""Flatten the contents of the pseudo-module into the globals
namespace."""
if keys is None:
keys = self.__dict__.keys() + self.__class__.__dict__.keys()
dict = {}
for key in keys:
# The pseudomodule is really a class instance, so we need to
# fumble use getattr instead of simply fumbling through the
# instance's __dict__.
dict[key] = getattr(self, key)
# Stomp everything into the globals namespace.
self.globals.update(dict)
# Prefix.
def getPrefix(self):
"""Get the current prefix."""
return self.prefix
def setPrefix(self, prefix):
"""Set the prefix."""
self.prefix = prefix
# Diversions.
def stopDiverting(self):
"""Stop any diverting."""
self.stream().revert()
def createDiversion(self, name):
"""Create a diversion (but do not divert to it) if it does not
already exist."""
self.stream().create(name)
def retrieveDiversion(self, name):
"""Retrieve the diversion object associated with the name."""
return self.stream().retrieve(name)
def startDiversion(self, name):
"""Start diverting to the given diversion name."""
self.stream().divert(name)
def playDiversion(self, name):
"""Play the given diversion and then purge it."""
self.stream().undivert(name, True)
def replayDiversion(self, name):
"""Replay the diversion without purging it."""
self.stream().undivert(name, False)
def purgeDiversion(self, name):
"""Eliminate the given diversion."""
self.stream().purge(name)
def playAllDiversions(self):
"""Play all existing diversions and then purge them."""
self.stream().undivertAll(True)
def replayAllDiversions(self):
"""Replay all existing diversions without purging them."""
self.stream().undivertAll(False)
def purgeAllDiversions(self):
"""Purge all existing diversions."""
self.stream().purgeAll()
def getCurrentDiversion(self):
"""Get the name of the current diversion."""
return self.stream().currentDiversion
def getAllDiversions(self):
"""Get the names of all existing diversions."""
names = self.stream().diversions.keys()
names.sort()
return names
# Filter.
def resetFilter(self):
"""Reset the filter so that it does no filtering."""
self.stream().install(None)
def nullFilter(self):
"""Install a filter that will consume all text."""
self.stream().install(0)
def getFilter(self):
"""Get the current filter."""
filter = self.stream().filter
if filter is self.stream().file:
return None
else:
return filter
def setFilter(self, shortcut):
"""Set the filter."""
self.stream().install(shortcut)
def attachFilter(self, shortcut):
"""Attach a single filter to the end of the current filter chain."""
self.stream().attach(shortcut)
class Document:
"""A representation of an individual EmPy document, as used by a
processor."""
def __init__(self, ID, filename):
self.ID = ID
self.filename = filename
self.significators = {}
class Processor:
"""An entity which is capable of processing a hierarchy of EmPy
files and building a dictionary of document objects associated
with them describing their significator contents."""
DEFAULT_EMPY_EXTENSIONS = ('.em',)
SIGNIFICATOR_RE = re.compile(SIGNIFICATOR_RE_STRING)
def __init__(self, factory=Document):
self.factory = factory
self.documents = {}
def identifier(self, pathname, filename): return filename
def clear(self):
self.documents = {}
def scan(self, basename, extensions=DEFAULT_EMPY_EXTENSIONS):
if type(extensions) is types.StringType:
extensions = (extensions,)
def _noCriteria(x):
return True
def _extensionsCriteria(pathname, extensions=extensions):
if extensions:
for extension in extensions:
if pathname[-len(extension):] == extension:
return True
return False
else:
return True
self.directory(basename, _noCriteria, _extensionsCriteria, None)
self.postprocess()
def postprocess(self):
pass
def directory(self, basename, dirCriteria, fileCriteria, depth=None):
if depth is not None:
if depth <= 0:
return
else:
depth = depth - 1
filenames = os.listdir(basename)
for filename in filenames:
pathname = os.path.join(basename, filename)
if os.path.isdir(pathname):
if dirCriteria(pathname):
self.directory(pathname, dirCriteria, fileCriteria, depth)
elif os.path.isfile(pathname):
if fileCriteria(pathname):
documentID = self.identifier(pathname, filename)
document = self.factory(documentID, pathname)
self.file(document, open(pathname))
self.documents[documentID] = document
def file(self, document, file):
while True:
line = file.readline()
if not line:
break
self.line(document, line)
def line(self, document, line):
match = self.SIGNIFICATOR_RE.search(line)
if match:
key, valueS = match.groups()
valueS = string.strip(valueS)
if valueS:
value = eval(valueS)
else:
value = None
document.significators[key] = value
def expand(_data, _globals=None, \
_argv=None, _prefix=DEFAULT_PREFIX, _pseudo=None, _options=None, \
**_locals):
"""Do an atomic expansion of the given source data, creating and
shutting down an interpreter dedicated to the task. The sys.stdout
object is saved off and then replaced before this function
returns."""
if len(_locals) == 0:
# If there were no keyword arguments specified, don't use a locals
# dictionary at all.
_locals = None
output = NullFile()
interpreter = Interpreter(output, argv=_argv, prefix=_prefix, \
pseudo=_pseudo, options=_options, \
globals=_globals)
if interpreter.options.get(OVERRIDE_OPT, True):
oldStdout = sys.stdout
try:
result = interpreter.expand(_data, _locals)
finally:
interpreter.shutdown()
if _globals is not None:
interpreter.unfix() # remove pseudomodule to prevent clashes
if interpreter.options.get(OVERRIDE_OPT, True):
sys.stdout = oldStdout
return result
def environment(name, default=None):
"""Get data from the current environment. If the default is True
or False, then presume that we're only interested in the existence
or non-existence of the environment variable."""
if os.environ.has_key(name):
# Do the True/False test by value for future compatibility.
if default == False or default == True:
return True
else:
return os.environ[name]
else:
return default
def info(table):
DEFAULT_LEFT = 28
maxLeft = 0
maxRight = 0
for left, right in table:
if len(left) > maxLeft:
maxLeft = len(left)
if len(right) > maxRight:
maxRight = len(right)
FORMAT = ' %%-%ds %%s\n' % max(maxLeft, DEFAULT_LEFT)
for left, right in table:
if right.find('\n') >= 0:
for right in right.split('\n'):
sys.stderr.write(FORMAT % (left, right))
left = ''
else:
sys.stderr.write(FORMAT % (left, right))
def usage(verbose=True):
"""Print usage information."""
programName = sys.argv[0]
def warn(line=''):
sys.stderr.write("%s\n" % line)
warn("""\
Usage: %s [options] [<filename, or '-' for stdin> [<argument>...]]
Welcome to EmPy version %s.""" % (programName, __version__))
warn()
warn("Valid options:")
info(OPTION_INFO)
if verbose:
warn()
warn("The following markups are supported:")
info(MARKUP_INFO)
warn()
warn("Valid escape sequences are:")
info(ESCAPE_INFO)
warn()
warn("The %s pseudomodule contains the following attributes:" % \
DEFAULT_PSEUDOMODULE_NAME)
info(PSEUDOMODULE_INFO)
warn()
warn("The following environment variables are recognized:")
info(ENVIRONMENT_INFO)
warn()
warn(USAGE_NOTES)
else:
warn()
warn("Type %s -H for more extensive help." % programName)
def invoke(args):
"""Run a standalone instance of an EmPy interpeter."""
# Initialize the options.
_output = None
_options = {BUFFERED_OPT: environment(BUFFERED_ENV, False),
RAW_OPT: environment(RAW_ENV, False),
EXIT_OPT: True,
FLATTEN_OPT: environment(FLATTEN_ENV, False),
OVERRIDE_OPT: not environment(NO_OVERRIDE_ENV, False),
CALLBACK_OPT: False}
_preprocessing = []
_prefix = environment(PREFIX_ENV, DEFAULT_PREFIX)
_pseudo = environment(PSEUDO_ENV, None)
_interactive = environment(INTERACTIVE_ENV, False)
_extraArguments = environment(OPTIONS_ENV)
_binary = -1 # negative for not, 0 for default size, positive for size
_unicode = environment(UNICODE_ENV, False)
_unicodeInputEncoding = environment(INPUT_ENCODING_ENV, None)
_unicodeOutputEncoding = environment(OUTPUT_ENCODING_ENV, None)
_unicodeInputErrors = environment(INPUT_ERRORS_ENV, None)
_unicodeOutputErrors = environment(OUTPUT_ERRORS_ENV, None)
_hooks = []
_pauseAtEnd = False
_relativePath = False
if _extraArguments is not None:
_extraArguments = string.split(_extraArguments)
args = _extraArguments + args
# Parse the arguments.
pairs, remainder = getopt.getopt(args, 'VhHvkp:m:frino:a:buBP:I:D:E:F:', ['version', 'help', 'extended-help', 'verbose', 'null-hook', 'suppress-errors', 'prefix=', 'no-prefix', 'module=', 'flatten', 'raw-errors', 'interactive', 'no-override-stdout', 'binary', 'chunk-size=', 'output=' 'append=', 'preprocess=', 'import=', 'define=', 'execute=', 'execute-file=', 'buffered-output', 'pause-at-end', 'relative-path', 'no-callback-error', 'no-bangpath-processing', 'unicode', 'unicode-encoding=', 'unicode-input-encoding=', 'unicode-output-encoding=', 'unicode-errors=', 'unicode-input-errors=', 'unicode-output-errors='])
for option, argument in pairs:
if option in ('-V', '--version'):
sys.stderr.write("%s version %s\n" % (__program__, __version__))
return
elif option in ('-h', '--help'):
usage(False)
return
elif option in ('-H', '--extended-help'):
usage(True)
return
elif option in ('-v', '--verbose'):
_hooks.append(VerboseHook())
elif option in ('--null-hook',):
_hooks.append(Hook())
elif option in ('-k', '--suppress-errors'):
_options[EXIT_OPT] = False
_interactive = True # suppress errors implies interactive mode
elif option in ('-m', '--module'):
_pseudo = argument
elif option in ('-f', '--flatten'):
_options[FLATTEN_OPT] = True
elif option in ('-p', '--prefix'):
_prefix = argument
elif option in ('--no-prefix',):
_prefix = None
elif option in ('-r', '--raw-errors'):
_options[RAW_OPT] = True
elif option in ('-i', '--interactive'):
_interactive = True
elif option in ('-n', '--no-override-stdout'):
_options[OVERRIDE_OPT] = False
elif option in ('-o', '--output'):
_output = argument, 'w', _options[BUFFERED_OPT]
elif option in ('-a', '--append'):
_output = argument, 'a', _options[BUFFERED_OPT]
elif option in ('-b', '--buffered-output'):
_options[BUFFERED_OPT] = True
elif option in ('-B',): # DEPRECATED
_options[BUFFERED_OPT] = True
elif option in ('--binary',):
_binary = 0
elif option in ('--chunk-size',):
_binary = int(argument)
elif option in ('-P', '--preprocess'):
_preprocessing.append(('pre', argument))
elif option in ('-I', '--import'):
for module in string.split(argument, ','):
module = string.strip(module)
_preprocessing.append(('import', module))
elif option in ('-D', '--define'):
_preprocessing.append(('define', argument))
elif option in ('-E', '--execute'):
_preprocessing.append(('exec', argument))
elif option in ('-F', '--execute-file'):
_preprocessing.append(('file', argument))
elif option in ('-u', '--unicode'):
_unicode = True
elif option in ('--pause-at-end',):
_pauseAtEnd = True
elif option in ('--relative-path',):
_relativePath = True
elif option in ('--no-callback-error',):
_options[CALLBACK_OPT] = True
elif option in ('--no-bangpath-processing',):
_options[BANGPATH_OPT] = False
elif option in ('--unicode-encoding',):
_unicodeInputEncoding = _unicodeOutputEncoding = argument
elif option in ('--unicode-input-encoding',):
_unicodeInputEncoding = argument
elif option in ('--unicode-output-encoding',):
_unicodeOutputEncoding = argument
elif option in ('--unicode-errors',):
_unicodeInputErrors = _unicodeOutputErrors = argument
elif option in ('--unicode-input-errors',):
_unicodeInputErrors = argument
elif option in ('--unicode-output-errors',):
_unicodeOutputErrors = argument
# Set up the Unicode subsystem if required.
if _unicode or \
_unicodeInputEncoding or _unicodeOutputEncoding or \
_unicodeInputErrors or _unicodeOutputErrors:
theSubsystem.initialize(_unicodeInputEncoding, \
_unicodeOutputEncoding, \
_unicodeInputErrors, _unicodeOutputErrors)
# Now initialize the output file if something has already been selected.
if _output is not None:
_output = apply(AbstractFile, _output)
# Set up the main filename and the argument.
if not remainder:
remainder.append('-')
filename, arguments = remainder[0], remainder[1:]
# Set up the interpreter.
if _options[BUFFERED_OPT] and _output is None:
raise ValueError, "-b only makes sense with -o or -a arguments"
if _prefix == 'None':
_prefix = None
if _prefix and type(_prefix) is types.StringType and len(_prefix) != 1:
raise Error, "prefix must be single-character string"
interpreter = Interpreter(output=_output, \
argv=remainder, \
prefix=_prefix, \
pseudo=_pseudo, \
options=_options, \
hooks=_hooks)
try:
# Execute command-line statements.
i = 0
for which, thing in _preprocessing:
if which == 'pre':
command = interpreter.file
target = theSubsystem.open(thing, 'r')
name = thing
elif which == 'define':
command = interpreter.string
if string.find(thing, '=') >= 0:
target = '%s{%s}' % (_prefix, thing)
else:
target = '%s{%s = None}' % (_prefix, thing)
name = '<define:%d>' % i
elif which == 'exec':
command = interpreter.string
target = '%s{%s}' % (_prefix, thing)
name = '<exec:%d>' % i
elif which == 'file':
command = interpreter.string
name = '<file:%d (%s)>' % (i, thing)
target = '%s{execfile("""%s""")}' % (_prefix, thing)
elif which == 'import':
command = interpreter.string
name = '<import:%d>' % i
target = '%s{import %s}' % (_prefix, thing)
else:
assert 0
interpreter.wrap(command, (target, name))
i = i + 1
# Now process the primary file.
interpreter.ready()
if filename == '-':
if not _interactive:
name = '<stdin>'
path = ''
file = sys.stdin
else:
name, file = None, None
else:
name = filename
file = theSubsystem.open(filename, 'r')
path = os.path.split(filename)[0]
if _relativePath:
sys.path.insert(0, path)
if file is not None:
if _binary < 0:
interpreter.wrap(interpreter.file, (file, name))
else:
chunkSize = _binary
interpreter.wrap(interpreter.binary, (file, name, chunkSize))
# If we're supposed to go interactive afterwards, do it.
if _interactive:
interpreter.interact()
finally:
interpreter.shutdown()
# Finally, if we should pause at the end, do it.
if _pauseAtEnd:
try:
raw_input()
except EOFError:
pass
def main():
invoke(sys.argv[1:])
if __name__ == '__main__': main()
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