From cfad3eb37147c3cbe36f53bca54ebb6f10b4c1ce Mon Sep 17 00:00:00 2001
From: Jussi Pakkanen <jpakkane@gmail.com>
Date: Wed, 26 Dec 2012 20:58:48 +0200
Subject: [PATCH] Created an interpreter class and even made it interpret
 something.

---
 interpreter.py | 44 ++++++++++++++++++++++++++++++++++++++++++++
 nodes.py       |  6 ++++++
 parser.py      |  7 ++++++-
 3 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100755 interpreter.py

diff --git a/interpreter.py b/interpreter.py
new file mode 100755
index 000000000..91b6a7cc7
--- /dev/null
+++ b/interpreter.py
@@ -0,0 +1,44 @@
+#!/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
+
+class InterpreterException(Exception):
+    pass
+
+class InvalidCode(InterpreterException):
+    pass
+
+class Interpreter():
+    
+    def __init__(self, code):
+        self.ast = parser.build_ast(code)
+        self.sanity_check_ast()
+        
+    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')
+            
+
+if __name__ == '__main__':
+    code = "project('myawesomeproject')"
+    i = Interpreter(code)
diff --git a/nodes.py b/nodes.py
index 850cffb14..952319d1b 100644
--- a/nodes.py
+++ b/nodes.py
@@ -50,6 +50,9 @@ class FunctionCall(Statement):
         Statement.__init__(self)
         self.func_name = func_name
         self.arguments = arguments
+        
+    def get_function_name(self):
+        return self.func_name.value
 
 class MethodCall(Statement):
     def __init__(self, object_name, method_name, arguments):
@@ -71,6 +74,9 @@ class CodeBlock(Statement):
         
     def prepend(self, statement):
         self.statements = [statement] + self.statements
+        
+    def get_statements(self):
+        return self.statements
 
 class Arguments(Statement):
     def __init__(self):
diff --git a/parser.py b/parser.py
index a04e423ab..639a19ae3 100755
--- a/parser.py
+++ b/parser.py
@@ -143,10 +143,15 @@ def test_parser():
     objectname.methodname(abc)
     emptycall()
     """
+    print(build_ast(code))
+
+def build_ast(code):
+    if not code.endswith('\n'):
+        code = code + '\n'
     lex.lex()
     parser = yacc.yacc()
     result = parser.parse(code)
-    print(result)
+    return result
 
 if __name__ == '__main__':
     #test_lexer()