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#!/usr/bin/python3 -tt
# Copyright 2012 Jussi Pakkanen
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import parser
import nodes
import environment
class InterpreterException(Exception):
pass
class InvalidCode(InterpreterException):
pass
class InvalidArguments(InterpreterException):
pass
class Interpreter():
def __init__(self, code):
self.ast = parser.build_ast(code)
self.sanity_check_ast()
self.project = None
self.compilers = []
def sanity_check_ast(self):
if not isinstance(self.ast, nodes.CodeBlock):
raise InvalidCode('AST is of invalid type. Possibly a bug in the parser.')
if len(self.ast.get_statements()) == 0:
raise InvalidCode('No statements in code.')
first = self.ast.get_statements()[0]
if not isinstance(first, nodes.FunctionCall) or first.get_function_name() != 'project':
raise InvalidCode('First statement must be a call to project')
def run(self):
i = 0
statements = self.ast.get_statements()
while i < len(statements):
cur = statements[i]
if isinstance(cur, nodes.FunctionCall):
self.function_call(cur)
else:
print("Unknown statement in line %d." % cur.lineno())
i += 1
def validate_arguments(self, args, argcount, arg_types):
if argcount is not None:
if argcount != len(args):
raise InvalidArguments('Expected %d arguments, got %d',
argcount, len(args))
for i in range(min(len(args), len(arg_types))):
wanted = arg_types[i]
actual = args[i]
if wanted != None:
if not isinstance(actual, wanted):
raise InvalidArguments('Incorrect argument type.')
def func_project(self, node, args):
self.validate_arguments(args, 1, [nodes.StringStatement])
if self.project is not None:
raise InvalidCode('Second call to project() on line %d.' % node.lineno())
self.project = args[0].get_string()
print("Project name is %s." % self.project)
def func_message(self, node, args):
self.validate_arguments(args, 1, [nodes.StringStatement])
print('Message: %s' % args[0].get_string())
def func_language(self, node, args):
self.validate_arguments(args, 1, [nodes.StringStatement])
if len(self.compilers) > 0:
raise InvalidCode('Function language() can only be called once (line %d).' % node.lineno())
lang = args[0].get_string()
if lang.lower() == 'c':
self.compilers.append(environment.detect_c_compiler('gcc'))
else:
raise InvalidCode('Tried to use unknown language "%s".' % lang)
def function_call(self, node):
func_name = node.get_function_name()
args = node.arguments.arguments
if func_name == 'project':
self.func_project(node, args)
elif func_name == 'message':
self.func_message(node, args)
elif func_name == 'language':
self.func_language(node, args)
else:
raise InvalidCode('Unknown function "%s".' % func_name)
if __name__ == '__main__':
code = """project('myawesomeproject')
message('I can haz text printed out?')
message('It workses!')
language('c')
"""
i = Interpreter(code)
i.run()
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