def __init__(self, program_name, program, namespace, debug=False): """ :param str program_name: name of the program :param str program: program to execute :param dict namespace: Namespace in which program executes """ self.debug = debug self._program_name = program_name self._program = program self._namespace = namespace # Keep this pointer self._controller = BlockExecutionController(None)
class ProgramExecuter(object):
"""
Executes a program. Provides exception reporting.
"""
def __init__(self, program_name, program, namespace, debug=False):
"""
:param str program_name: name of the program
:param str program: program to execute
:param dict namespace: Namespace in which program executes
"""
self.debug = debug
self._program_name = program_name
self._program = program
self._namespace = namespace # Keep this pointer
self._controller = BlockExecutionController(None)
def getNamespace(self):
return self._namespace
def _wrapProgram(self):
"""
Puts a wrapper around the program so that an exception can
be caught and its location determined within the program.
:returns str: program wrapped in try/catch blocks
:sideeffects: puts CONTROLLER object in the namespace
"""
self._namespace[CONTROLLER] = self._controller
sa = StatementAccumulator()
sa.add("try:")
sa.indent(1)
statement = "%s.startBlock('%s')" % (CONTROLLER, self._program_name)
sa.add(statement)
sa.add(self._program)
statement = "%s.endBlock()" % CONTROLLER
sa.add(statement)
sa.indent(-1)
statement = """
except Exception as exc:
%s.exceptionForBlock(exc)""" % CONTROLLER
sa.add(statement)
return sa.get()
def execute(self):
"""
Executes the program.
:returns str: error message or None
"""
# Check for syntax errors
error = None
wrapped_program = self._wrapProgram()
try:
exec wrapped_program in self._namespace
except Exception as exc:
if isinstance(exc, exceptions.SyntaxError):
error = exc
if error is not None:
msg = "In %s, syntax error at line %d: %s" % \
(self._program_name, error.lineno, str(error))
return msg
return self._controller.formatError()
def checkSyntax(self, adjust_linenumber=0):
"""
Checks the syntax.
:param int adjust_linenumber:
:returns str: error message or None
"""
# Check for syntax errors
msg = None
lineno = None
error = None
try:
exec self._program in self._namespace
except Exception as exc:
if isinstance(exc, exceptions.SyntaxError):
error = exc
lineno = exc.lineno + adjust_linenumber
if error is not None:
msg = "In %s, syntax error at line %d: %s" % \
(self._program_name, lineno, str(error))
return msg
def getException(self):
return self._controller.getException()
