Hacking on some AST, I think.

hy/compiler/ast27.py

@@ -2,6 +2,7 @@
 import ast
 
 from hy.lang.expression import HYExpression
+from hy.lang.number import HYNumber
 from hy.lang.string import HYString
 
 from hy.lang.builtins import builtins
@@ -23,8 +24,25 @@ def _ast_print(node, children):
     )
 
 
+def _ast_binop(node, children):
+    inv = node.get_invocation()
+    ops = {
+        "+": ast.Add
+    }
+    op = ops[inv['function']]
+
+    left = children.pop(0)
+    calc = None
+
+    for child in children:
+        calc = ast.BinOp(left=left, op=op(), right=child)
+        left = calc
+
+    return calc
+
 special_cases = {
-    "print": _ast_print
+    "print": _ast_print,
+    "+": _ast_binop
 }
 
 
@@ -32,14 +50,15 @@ class AST27Converter(object):
     def __init__(self):
         self.table = {
             HYString: self.render_string,
-            HYExpression: self.render_expression
+            HYExpression: self.render_expression,
+            HYNumber: self.render_number
         }
 
     def render_string(self, node):
         return ast.Str(s=node)
 
     def render_number(self, node):
-        pass
+        return ast.Num(n=node)
 
     def render_expression(self, node):
         c = []
@@ -68,3 +87,4 @@ def forge_ast(name, forest):
         statements.append(conv.render(tree))
 
     print [ast.dump(x) for x in statements]
+    return ast.fix_missing_locations(ast.Module(body=statements))