1 files changed, 144 insertions, 0 deletions
diff --git a/src/nodes.py b/src/nodes.py
new file mode 100644
index 0000000..ea9517d
--- /dev/null
+++ b/src/nodes.py
@@ -0,0 +1,144 @@
+# Copyright 2015 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is licensed under the terms of the MIT License.
+# See LICENSE.txt for details.
+
+class ProgramNode:
+    def __init__(self, stmt_list):
+        self._stmt_list = stmt_list
+
+    def execute(self):
+        for stmt in self._stmt_list:
+            stmt.execute()
+
+_varmap = { }
+
+class CompoundStatementNode:
+    def __init__(self, stmt_list):
+        self._stmt_list = stmt_list
+
+    def execute(self):
+        for stmt in self._stmt_list:
+            stmt.execute()
+
+class EmptyStatementNode:
+    def execute(self):
+        pass
+
+class AssignmentNode:
+    def __init__(self, identifier, arithm_expr):
+        self._identifier = identifier
+        self._arithm_expr = arithm_expr
+
+    def execute(self):
+        _varmap[str(self._identifier)] = self._arithm_expr.execute()
+        return None
+
+class PrintStatementNode:
+    def __init__(self, arithm_expr):
+        self._arithm_expr = arithm_expr
+
+    def execute(self):
+        print(self._arithm_expr.execute())
+        return None
+
+class IdentifierNode:
+    def __init__(self, identifier):
+        self._identifier = identifier
+
+    def execute(self):
+        return _varmap[str(self._identifier)]
+
+class AdditionOpNode:
+    def __init__(self, left, right):
+        self._left = left
+        self._right = right
+
+    def execute(self):
+        return self._left.execute() + self._right.execute()
+
+class SubtractionOpNode:
+    def __init__(self, left, right):
+        self._left = left
+        self._right = right
+
+    def execute(self):
+        return self._left.execute() + self._right.execute()
+
+class MultiplicationOpNode:
+    def __init__(self, left, right):
+        self._left = left
+        self._right = right
+
+    def execute(self):
+        return self._left.execute() * self._right.execute()
+
+class DivisionOpNode:
+    def __init__(self, left, right):
+        self._left = left
+        self._right = right
+
+    def execute(self):
+        return self._left.execute() / self._right.execute()
+
+class IntegerNumberNode:
+    def __init__(self, n):
+        self._n = n
+
+    def execute(self):
+        return int(self._n)
+
+class FloatingPointNumberNode:
+    def __init__(self, n):
+        self._n = n
+
+    def execute(self):
+        return float(self._n)
+
+class IfStatementNode:
+    def __init__(self, cond, body):
+        self._cond = cond
+        self._body = body
+
+    def execute(self):
+        if self._cond.execute():
+            return self._body.execute()
+
+class TrueNode:
+    def execute(self):
+        return True
+
+class FalseNode:
+    def execute(self):
+        return False
+
+class AndOpNode:
+    def __init__(self, left, right):
+        self._left = left
+        self._right = right
+
+    def execute(self):
+        return self._left.execute() and self._right.execute()
+
+class OrOpNode:
+    def __init__(self, left, right):
+        self._left = left
+        self._right = right
+
+    def execute(self):
+        return self._left.execute() or self._right.execute()
+
+class EqualsOpNode:
+    def __init__(self, left, right):
+        self._left = left
+        self._right = right
+
+    def execute(self):
+        return self._left.execute() == self._right.execute()
+
+class NotEqualsOpNode:
+    def __init__(self, left, right):
+        self._left = left
+        self._right = right
+
+    def execute(self):
+        return self._left.execute() != self._right.execute()